Cyanogen bromide (CNBr). A compound used in molecular biology to digest some proteins and as a coupling reagent for phosphoroamidate or pyrophosphate internucleotide bonds in DNA duplexes.
Salts of hydrobromic acid, HBr, with the bromine atom in the 1- oxidation state. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
A serine endopeptidase that is formed from TRYPSINOGEN in the pancreas. It is converted into its active form by ENTEROPEPTIDASE in the small intestine. It catalyzes hydrolysis of the carboxyl group of either arginine or lysine. EC
Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.
A serine endopeptidase secreted by the pancreas as its zymogen, CHYMOTRYPSINOGEN and carried in the pancreatic juice to the duodenum where it is activated by TRYPSIN. It selectively cleaves aromatic amino acids on the carboxyl side.
A thermostable extracellular metalloendopeptidase containing four calcium ions. (Enzyme Nomenclature, 1992)
Formed from pig pepsinogen by cleavage of one peptide bond. The enzyme is a single polypeptide chain and is inhibited by methyl 2-diaazoacetamidohexanoate. It cleaves peptides preferentially at the carbonyl linkages of phenylalanine or leucine and acts as the principal digestive enzyme of gastric juice.
Enzymes that act at a free C-terminus of a polypeptide to liberate a single amino acid residue.
The sum of the weight of all the atoms in a molecule.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Analysis of PEPTIDES that are generated from the digestion or fragmentation of a protein or mixture of PROTEINS, by ELECTROPHORESIS; CHROMATOGRAPHY; or MASS SPECTROMETRY. The resulting peptide fingerprints are analyzed for a variety of purposes including the identification of the proteins in a sample, GENETIC POLYMORPHISMS, patterns of gene expression, and patterns diagnostic for diseases.
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.
Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.
A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of SKIN; CONNECTIVE TISSUE; and the organic substance of bones (BONE AND BONES) and teeth (TOOTH).
A trypanocidal agent and possible antiviral agent that is widely used in experimental cell biology and biochemistry. Ethidium has several experimentally useful properties including binding to nucleic acids, noncompetitive inhibition of nicotinic acetylcholine receptors, and fluorescence among others. It is most commonly used as the bromide.
A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
The composition, conformation, and properties of atoms and molecules, and their reaction and interaction processes.
The parts of a macromolecule that directly participate in its specific combination with another molecule.
Compounds and molecular complexes that consist of very large numbers of atoms and are generally over 500 kDa in size. In biological systems macromolecular substances usually can be visualized using ELECTRON MICROSCOPY and are distinguished from ORGANELLES by the lack of a membrane structure.
Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.
Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.
Separation technique in which the stationary phase consists of ion exchange resins. The resins contain loosely held small ions that easily exchange places with other small ions of like charge present in solutions washed over the resins.
Hydrolases that specifically cleave the peptide bonds found in PROTEINS and PEPTIDES. Examples of sub-subclasses for this group include EXOPEPTIDASES and ENDOPEPTIDASES.
Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
An enzyme catalyzing the transfer of a phosphate group from 3-phospho-D-glycerate in the presence of ATP to yield 3-phospho-D-glyceroyl phosphate and ADP. EC
Analogs of those substrates or compounds which bind naturally at the active sites of proteins, enzymes, antibodies, steroids, or physiological receptors. These analogs form a stable covalent bond at the binding site, thereby acting as inhibitors of the proteins or steroids.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
A subclass of PEPTIDE HYDROLASES that catalyze the internal cleavage of PEPTIDES or PROTEINS.
A paralytic condition of the legs caused by ingestion of lathyrogens, especially BETA-AMINOPROPIONITRILE or beta-N-oxalyl amino-L-alanine, which are found in the seeds of plants of the genus LATHYRUS.
Brominated hydrocarbons are organic compounds containing carbon (C), hydrogen (H) atoms, and bromine (Br) atoms, where bromine atoms replace some or all of the hydrogen atoms in the hydrocarbon structure.
Biologically active molecules which are covalently bound to the enzymes or binding proteins normally acting on them. Binding occurs due to activation of the label by ultraviolet light. These labels are used primarily to identify binding sites on proteins.
A biosynthetic precursor of collagen containing additional amino acid sequences at the amino-terminal and carboxyl-terminal ends of the polypeptide chains.
A zinc containing enzyme of the hydrolase class that catalyzes the removal of the N-terminal amino acid from most L-peptides, particularly those with N-terminal leucine residues but not those with N-terminal lysine or arginine residues. This occurs in tissue cell cytosol, with high activity in the duodenum, liver, and kidney. The activity of this enzyme is commonly assayed using a leucine arylamide chromogenic substrate such as leucyl beta-naphthylamide.
A muscarinic antagonist structurally related to ATROPINE but often considered safer and more effective for inhalation use. It is used for various bronchial disorders, in rhinitis, and as an antiarrhythmic.
Compounds that contain a 1-dimethylaminonaphthalene-5-sulfonyl group.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
A sulfur-containing essential L-amino acid that is important in many body functions.
A family of galactoside hydrolases that hydrolyze compounds with an O-galactosyl linkage. EC 3.2.1.-.
Sites on an antigen that interact with specific antibodies.
**Maleates** are organic compounds that contain a carboxylic acid group and a hydroxyl group attached to adjacent carbon atoms, often used as intermediates in the synthesis of pharmaceuticals and other chemicals, or as drugs themselves, such as maleic acid or its salts.
A hydroxylated derivative of the amino acid LYSINE that is present in certain collagens.
A chromatographic technique that utilizes the ability of biological molecules to bind to certain ligands specifically and reversibly. It is used in protein biochemistry. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Benzoic acid esters or salts substituted with one or more iodine atoms.
A colorless inorganic compound (HONH2) used in organic synthesis and as a reducing agent, due to its ability to donate nitric oxide.
A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.
The largest class of organic compounds, including STARCH; GLYCOGEN; CELLULOSE; POLYSACCHARIDES; and simple MONOSACCHARIDES. Carbohydrates are composed of carbon, hydrogen, and oxygen in a ratio of Cn(H2O)n.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
Contractile tissue that produces movement in animals.
The rate dynamics in chemical or physical systems.
A system of universal human blood group isoantigens with many associated subgroups. The M and N traits are codominant and the S and s traits are probably very closely linked alleles, including the U antigen. This system is most frequently used in paternity studies.
Inorganic salts of HYDROGEN CYANIDE containing the -CN radical. The concept also includes isocyanides. It is distinguished from NITRILES, which denotes organic compounds containing the -CN radical.
Organic compounds that contain the (-NH2OH) radical.
A proteolytic enzyme obtained from Carica papaya. It is also the name used for a purified mixture of papain and CHYMOPAPAIN that is used as a topical enzymatic debriding agent. EC
Any member of the group of ENDOPEPTIDASES containing at the active site a serine residue involved in catalysis.
Techniques used to separate mixtures of substances based on differences in the relative affinities of the substances for mobile and stationary phases. A mobile phase (fluid or gas) passes through a column containing a stationary phase of porous solid or liquid coated on a solid support. Usage is both analytical for small amounts and preparative for bulk amounts.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
An electrochemical process in which macromolecules or colloidal particles with a net electric charge migrate in a solution under the influence of an electric current.
The process of cleaving a chemical compound by the addition of a molecule of water.
A brominating agent that replaces hydrogen atoms in benzylic or allylic positions. It is used in the oxidation of secondary alcohols to ketones and in controlled low-energy brominations. (From Miall's Dictionary of Chemistry, 5th ed; Hawley's Condensed Chemical Dictionary, 12th ed,).
Analogs and derivatives of atropine.
COLLAGEN DISEASES characterized by brittle, osteoporotic, and easily fractured bones. It may also present with blue sclerae, loose joints, and imperfect dentin formation. Most types are autosomal dominant and are associated with mutations in COLLAGEN TYPE I.
Antimuscarinic quaternary ammonium derivative of scopolamine used to treat cramps in gastrointestinal, urinary, uterine, and biliary tracts, and to facilitate radiologic visualization of the gastrointestinal tract.
The sequential correspondence of nucleotides in one nucleic acid molecule with those of another nucleic acid molecule. Sequence homology is an indication of the genetic relatedness of different organisms and gene function.
Technique involving the diffusion of antigen or antibody through a semisolid medium, usually agar or agarose gel, with the result being a precipitin reaction.
Venoms from snakes of the subfamily Crotalinae or pit vipers, found mostly in the Americas. They include the rattlesnake, cottonmouth, fer-de-lance, bushmaster, and American copperhead. Their venoms contain nontoxic proteins, cardio-, hemo-, cyto-, and neurotoxins, and many enzymes, especially phospholipases A. Many of the toxins have been characterized.
Carbodiimides are chemical compounds containing two nitrogen atoms and one carbon atom, often used in biochemistry for the formation of amide bonds, particularly in peptide synthesis and cross-linking of proteins or other biomolecules.
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
An analytical technique for resolution of a chemical mixture into its component compounds. Compounds are separated on an adsorbent paper (stationary phase) by their varied degree of solubility/mobility in the eluting solvent (mobile phase).
Large, hoofed mammals of the family EQUIDAE. Horses are active day and night with most of the day spent seeking and consuming food. Feeding peaks occur in the early morning and late afternoon, and there are several daily periods of rest.
A ZINC-dependent carboxypeptidase primary found in the DIGESTIVE SYSTEM. The enzyme catalyzes the preferential cleavage of a C-terminal peptidyl-L-lysine or arginine. It was formerly classified as EC and EC
A covalently linked dimeric nonessential amino acid formed by the oxidation of CYSTEINE. Two molecules of cysteine are joined together by a disulfide bridge to form cystine.
A genus of ascomycetous fungi, family Sordariaceae, order SORDARIALES, comprising bread molds. They are capable of converting tryptophan to nicotinic acid and are used extensively in genetic and enzyme research. (Dorland, 27th ed)
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
A method of gel filtration chromatography using agarose, the non-ionic component of agar, for the separation of compounds with molecular weights up to several million.
An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.
One of the minor protein components of skeletal muscle. Its function is to serve as the calcium-binding component in the troponin-tropomyosin B-actin-myosin complex by conferring calcium sensitivity to the cross-linked actin and myosin filaments.
The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.
An essential amino acid. It is often added to animal feed.
Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).
Common name for the species Gallus gallus, the domestic fowl, in the family Phasianidae, order GALLIFORMES. It is descended from the red jungle fowl of SOUTHEAST ASIA.

The heparin/heparan sulfate-binding site on apo-serum amyloid A. Implications for the therapeutic intervention of amyloidosis. (1/1543)

Serum amyloid A isoforms, apoSAA1 and apoSAA2, are apolipoproteins of unknown function that become major components of high density lipoprotein (HDL) during the acute phase of an inflammatory response. ApoSAA is also the precursor of inflammation-associated amyloid, and there is strong evidence that the formation of inflammation-associated and other types of amyloid is promoted by heparan sulfate (HS). Data presented herein demonstrate that both mouse and human apoSAA contain binding sites that are specific for heparin and HS, with no binding for the other major glycosaminoglycans detected. Cyanogen bromide-generated peptides of mouse apoSAA1 and apoSAA2 were screened for heparin binding activity. Two peptides, an apoSAA1-derived 80-mer (residues 24-103) and a smaller carboxyl-terminal 27-mer peptide of apoSAA2 (residues 77-103), were retained by a heparin column. A synthetic peptide corresponding to the CNBr-generated 27-mer also bound heparin, and by substituting or deleting one or more of its six basic residues (Arg-83, His-84, Arg-86, Lys-89, Arg-95, and Lys-102), their relative importance for heparin and HS binding was determined. The Lys-102 residue appeared to be required only for HS binding. The residues Arg-86, Lys-89, Arg-95, and Lys-102 are phylogenetically conserved suggesting that the heparin/HS binding activity may be an important aspect of the function of apoSAA. HS linked by its carboxyl groups to an Affi-Gel column or treated with carbodiimide to block its carboxyl groups lost the ability to bind apoSAA. HDL-apoSAA did not bind to heparin; however, it did bind to HS, an interaction to which apoA-I contributed. Results from binding experiments with Congo Red-Sepharose 4B columns support the conclusions of a recent structural study which found that heparin binding domains have a common spatial distance of about 20 A between their two outer basic residues. Our present work provides direct evidence that apoSAA can associate with HS (and heparin) and that the occupation of its binding site by HS, and HS analogs, likely caused the previously reported increase in amyloidogenic conformation (beta-sheet) of apoSAA2 (McCubbin, W. D., Kay, C. M., Narindrasorasak, S., and Kisilevsky, R. (1988) Biochem. J. 256, 775-783) and their amyloid-suppressing effects in vivo (Kisilevsky, R., Lemieux, L. J., Fraser, P. E., Kong, X., Hultin, P. G., and Szarek, W. A. (1995) Nat. Med. 1, 143-147), respectively.  (+info)

The amino acid sequence of rabbit cardiac troponin I. (2/1543)

The complete amino acid sequence of troponin I from rabbit cardiac muscle was determined by the isolation of four unique CNBr fragments, together with overlapping tryptic peptides containing radioactive methionine residues. Overlap data for residues 35-36, 93-94 and 140-145 are incomplete, the sequence at these positions being based on homology with the sequence of the fast-skeletal-muscle protein. Cardiac troponin I is a single polypeptide chain of 206 residues with mol.wt. 23550 and an extinction coefficient, E 1%,1cm/280, of 4.37. The protein has a net positive charge of 14 and is thus somewhat more basic than troponin I from fast-skeletal muscle. Comparison of the sequences of troponin I from cardiac and fast skeletal muscle show that the cardiac protein has 26 extra residues at the N-terminus which account for the larger size of the protein. In the remainder of sequence there is a considerable degree of homology, this being greater in the C-terminal two-thirds of the molecule. The region in the cardiac protein corresponding to the peptide with inhibitory activity from the fast-skeletal-muscle protein is very similar and it seems unlikely that this is the cause of the difference in inhibitory activity between the two proteins. The region responsible for binding troponin C, however, possesses a lower degree of homology. Detailed evidence on which the sequence is based has been deposited as Supplementary Publication SUP 50072 (20 pages), at the British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7QB, U.K., from whom copies may be obtained on the terms given in Biochem. J. (1976) 153, 5.  (+info)

The primary structure of the parvalbumin II of pike (Esox lucius). (3/1543)

The amino acid sequence of the parvalbumin II of the pike is reported. The protein has a molecular weight of 11 435. It consists of a single polypeptide chain of 107 amino acid residues with an acetyl group blocking the N-terminus and an alanine residue at the C-terminus. The molecule has been enzymically cleaved by trypsin, thermolysin and by the protease of the Staphylococcus aureus strain V8. Chemical cleavages make use of the CNBr reaction and of the sulfocyanoethylation method. The comparison of this amino acid sequence with that of the parvalbumin III of the pike indicates that these two homologous proteins belong respectively to two different subgroups derived from an early gene duplication of an ancestral gene at least prior to the differentiation of the Osteichthyes.  (+info)

Thermodynamic and kinetic analysis of the Escherichia coli thioredoxin-C' fragment complementation system. (4/1543)

Escherichia coli thioredoxin was cleaved with CNBr at its single Met residue at position 37, which lies in the middle of a long alpha-helix. The two fragments, 1-37 and 38-108, were purified and characterized by using CD and fluorescence spectroscopy. Both fragments lack structure at neutral pH and room temperature. The secondary and tertiary structural contents of the non-covalent complex formed on the mixing of the two peptide fragments are 47% and 35% of the intact protein respectively. The thermodynamics and kinetics of fragment association were characterized by titration calorimetry and stopped-flow fluorescence spectroscopy. Single phases were observed for both association and dissociation, with rate constants at 298 K of kon=4971+/-160 M-1.s -1 and koff=0. 063+/-0.009 s-1 respectively. The ratio kon/koff was very similar to the binding constant determined by titration calorimetry, suggesting that binding is a two-state process. The values for DeltaCp, DeltaH0 and DeltaG0 at 298 K for dissociation of the complex were 5.7 kJ. mol-1.K-1, 45.3 kJ.mol-1 and 29.8 kJ.mol-1 respectively. The value for DeltaH0 was linearly dependent on temperature from 8-40 degrees C, suggesting that DeltaCp is independent of temperature. The values for DeltaCp and DeltaG0 are very similar to the corresponding values for the unfolding of intact thioredoxin at 25 degrees C. However, both DeltaH0 and DeltaS are significantly more positive for dissociation of the complex, suggesting a decreased hydrophobic stabilization of the complex relative to the situation for intact thioredoxin.  (+info)

Oxidative refolding of recombinant prochymosin. (5/1543)

The disulphide-coupled refolding of recombinant prochymosin from Escherichia coli inclusion bodies was investigated. Prochymosin solubilized from inclusion bodies is endowed with free thiol groups and disulphide bonds. This partially reduced form undergoes renaturation more efficiently than the fully reduced form, suggesting that some native structural elements existing in inclusion bodies and remaining after denaturation function as nuclei to initiate correct refolding. This assumption is supported by the finding that in the solubilized prochymosin molecule the cysteine residues located in the N-terminal domain of the protein are not incorrectly paired with the other cysteines in the C-terminal domain. Addition of GSH/GSSG into the refolding system facilitates disulphide rearrangement and thus enhances renaturation, especially for the fully reduced prochymosin. Based on the results described in this and previous papers [Tang, Zhang and Yang (1994) Biochem. J. 301, 17-20], a model to depict the refolding process of prochymosin is proposed. Briefly, the refolding process of prochymosin consists of two stages: the formation and rearrangement of disulphide bonds occurs at the first stage in a pH11 buffer, whereas the formation and adjustment of tertiary structure leading to the native conformation takes place at the second stage at pH8. The pH11 conditions help polypeptides to refold in such a way as to favour the formation of native disulphide bonds. Disulphide rearrangement, the rate-limiting step during refolding, can be achieved by thiol/disulphide exchange initiated by free thiol groups present in the prochymosin polypeptide, GSH/GSSG or protein disulphide isomerase.  (+info)

Characterization of the myosin light chain kinase from smooth muscle as an actin-binding protein that assembles actin filaments in vitro. (6/1543)

In addition to its kinase activity, myosin light chain kinase has an actin-binding activity, which results in bundling of actin filaments [Hayakawa et al., Biochem. Biophys. Res. Commun. 199, 786-791, 1994]. There are two actin-binding sites on the kinase: calcium- and calmodulin-sensitive and insensitive sites [Ye et al., J. Biol. Chem. 272, 32182-32189, 1997]. The calcium/calmodulin-sensitive, actin-binding site is located at Asp2-Pro41 and the insensitive site is at Ser138-Met213. The cyanogen bromide fragment, consisting of Asp2-Met213, is furnished with both sites and is the actin-binding core of myosin light chain kinase. Cross-linking between the two sites assembles actin filaments into bundles. Breaking of actin-binding at the calcium/calmodulin-sensitive site by calcium/calmodulin disassembles the bundles.  (+info)

A study of renaturation of reduced hen egg white lysozyme. Enzymically active intermediates formed during oxidation of the reduced protein. (7/1543)

The material obtained from reduced hen egg white lysozyme after complete air oxidation at pH 8.0 and 37 degrees has yielded, by gel filtration on a Bio-Gel P-30 column, enzymically active species and an enzymically inactive form which eluted sooner than the active species but later than expected for a dimer of lysozyme. Reduced lysozyme also elutes at the same position as this inactive material. Examination of the fragments produced on CNBr cleavage of the inactive form indicates that at least 24% of the population contains incorrect disulfide bonds involving half-cystine residues 6, 30, 115, and 127. Tryptophan fluorescence and the intrinsic viscosity of the inactive form show an enlarged molecular domain with a disordered conformation. The yield of the inactive form increases as the oxidation of reduced lysozyme is accelerated using cupric ion. In the presence of 4 X 10(-5) M cupric ion, reduced lysozyme forms almost quantitatively the inactive form, which is almost completely converted to the native form by sulfhydryl-disulfide interchange catalyzed by thiol groups of either reduced lysozyme or beta-mercaptoethanol. The material trapped by alkylation of the free sulfhydryl groups with [1-14C]iodoacetic acid during the early stage of air oxidation of reduced lysozyme was fractionated by gel filtration to permit separation of the active species from the inactive form. Ion exchange chromatography of the active species yielded completely renatured lysozyme and three major enzymically active radioactive derivatives. Two of these derivatives contained approximately 2 mol of S-carboxymethylcysteine. Isolation and characterization of radioactive tryptic peptides from each of the three active forms, permitted the identification of Cys 6 and Cys 127, Cys 76 and 94, and Cys 80 as the sulfhydryl groups alkylated in these three incompletely oxidized, partially active forms. Thus, it appears that the interatomic interactions maintaining the compact three-dimensional structure of native lysozyme are operational even when one of these three native disulfide bonds between Cys 6 and Cys 127, Cys 76 and Cys 94, and Cys 64 and 80 is open.  (+info)

Hydrophobic photolabeling as a new method for structural characterization of molten globule and related protein folding intermediates. (8/1543)

Recent advances in attempts to unravel the protein folding mechanism have indicated the need to identify the folding intermediates. Despite their transient nature, in a number of cases it has been possible to detect and characterize some of the equilibrium intermediates, for example, the molten globule (MG) state. The key features of the MG state are retention of substantial secondary structure of the native state, considerable loss of tertiary structure leading to increased hydrophobic exposure, and a compact structure. NMR, circular dichroism, and fluorescence spectroscopies have been most useful in characterizing such intermediates. We report here a new method for structural characterization of the MG state that involves probing the exposed hydrophobic sites with a hydrophobic photoactivable reagent--2[3H]diazofluorene. This carbene-based reagent binds to hydrophobic sites, and on photolysis covalently attaches itself to the neighboring amino acid side chains. The reagent photolabels alpha-lactalbumin as a function of pH (3-7.4), the labeling at neutral pH being negligible and maximal at pH 3. Chemical and proteolytic fragmentation of the photolabeled protein followed by peptide sequencing permitted identification of the labeled residues. The results obtained indicate that the sequence corresponding to B (23-34) and C (86-98) helix of the native structure are extensively labeled. The small beta-domain (40-50) is poorly labeled, Val42 being the only residue that is significantly labeled. Our data, like NMR data, indicate that in the MG state of alpha-lactalbumin, the alpha-domain has a greater degree of persistent structure than the beta-domain. However, unlike the NMR method, the photolabeling method is not limited by the size of the protein and can provide information on several new residues, for example, Leu115. The current method using DAF thus allows identification of stable and hydrophobic exposed regions in folding intermediates as the reagent binds and on photolysis covalently links to these regions.  (+info)

Cyanogen bromide is a solid compound with the chemical formula (CN)Br. It is a highly reactive and toxic substance that is used in research and industrial settings for various purposes, such as the production of certain types of resins and gels. Cyanogen bromide is an alkyl halide, which means it contains a bromine atom bonded to a carbon atom that is also bonded to a cyano group (a nitrogen atom bonded to a carbon atom with a triple bond).

Cyanogen bromide is classified as a class B poison, which means it can cause harm or death if swallowed, inhaled, or absorbed through the skin. It can cause irritation and burns to the eyes, skin, and respiratory tract, and prolonged exposure can lead to more serious health effects, such as damage to the nervous system and kidneys. Therefore, it is important to handle cyanogen bromide with care and to use appropriate safety precautions when working with it.

In medical terms, "bromides" refer to salts or compounds that contain bromine, a chemical element. Historically, potassium bromide was used as a sedative and anticonvulsant in the 19th and early 20th centuries. However, its use has largely been discontinued due to side effects such as neurotoxicity and kidney damage.

In modern medical language, "bromides" can also refer to something that is unoriginal, dull, or lacking in creativity, often used to describe ideas or expressions that are trite or clichéd. This usage comes from the fact that bromide salts were once commonly used as a sedative and were associated with a lack of excitement or energy.

A peptide fragment is a short chain of amino acids that is derived from a larger peptide or protein through various biological or chemical processes. These fragments can result from the natural breakdown of proteins in the body during regular physiological processes, such as digestion, or they can be produced experimentally in a laboratory setting for research or therapeutic purposes.

Peptide fragments are often used in research to map the structure and function of larger peptides and proteins, as well as to study their interactions with other molecules. In some cases, peptide fragments may also have biological activity of their own and can be developed into drugs or diagnostic tools. For example, certain peptide fragments derived from hormones or neurotransmitters may bind to receptors in the body and mimic or block the effects of the full-length molecule.

An amino acid sequence is the specific order of amino acids in a protein or peptide molecule, formed by the linking of the amino group (-NH2) of one amino acid to the carboxyl group (-COOH) of another amino acid through a peptide bond. The sequence is determined by the genetic code and is unique to each type of protein or peptide. It plays a crucial role in determining the three-dimensional structure and function of proteins.

Trypsin is a proteolytic enzyme, specifically a serine protease, that is secreted by the pancreas as an inactive precursor, trypsinogen. Trypsinogen is converted into its active form, trypsin, in the small intestine by enterokinase, which is produced by the intestinal mucosa.

Trypsin plays a crucial role in digestion by cleaving proteins into smaller peptides at specific arginine and lysine residues. This enzyme helps to break down dietary proteins into amino acids, allowing for their absorption and utilization by the body. Additionally, trypsin can activate other zymogenic pancreatic enzymes, such as chymotrypsinogen and procarboxypeptidases, thereby contributing to overall protein digestion.

Amino acids are organic compounds that serve as the building blocks of proteins. They consist of a central carbon atom, also known as the alpha carbon, which is bonded to an amino group (-NH2), a carboxyl group (-COOH), a hydrogen atom (H), and a variable side chain (R group). The R group can be composed of various combinations of atoms such as hydrogen, oxygen, sulfur, nitrogen, and carbon, which determine the unique properties of each amino acid.

There are 20 standard amino acids that are encoded by the genetic code and incorporated into proteins during translation. These include:

1. Alanine (Ala)
2. Arginine (Arg)
3. Asparagine (Asn)
4. Aspartic acid (Asp)
5. Cysteine (Cys)
6. Glutamine (Gln)
7. Glutamic acid (Glu)
8. Glycine (Gly)
9. Histidine (His)
10. Isoleucine (Ile)
11. Leucine (Leu)
12. Lysine (Lys)
13. Methionine (Met)
14. Phenylalanine (Phe)
15. Proline (Pro)
16. Serine (Ser)
17. Threonine (Thr)
18. Tryptophan (Trp)
19. Tyrosine (Tyr)
20. Valine (Val)

Additionally, there are several non-standard or modified amino acids that can be incorporated into proteins through post-translational modifications, such as hydroxylation, methylation, and phosphorylation. These modifications expand the functional diversity of proteins and play crucial roles in various cellular processes.

Amino acids are essential for numerous biological functions, including protein synthesis, enzyme catalysis, neurotransmitter production, energy metabolism, and immune response regulation. Some amino acids can be synthesized by the human body (non-essential), while others must be obtained through dietary sources (essential).

Chymotrypsin is a proteolytic enzyme, specifically a serine protease, that is produced in the pancreas and secreted into the small intestine as an inactive precursor called chymotrypsinogen. Once activated, chymotrypsin helps to digest proteins in food by breaking down specific peptide bonds in protein molecules. Its activity is based on the recognition of large hydrophobic side chains in amino acids like phenylalanine, tryptophan, and tyrosine. Chymotrypsin plays a crucial role in maintaining normal digestion and absorption processes in the human body.

Thermolysin is not a medical term per se, but it is a bacterial enzyme that is often used in biochemistry and molecular biology research. Here's the scientific or biochemical definition:

Thermolysin is a zinc metalloprotease enzyme produced by the bacteria Geobacillus stearothermophilus. It has an optimum temperature for activity at around 65°C, and it can remain active in high temperatures, which makes it useful in various industrial applications. Thermolysin is known for its ability to cleave peptide bonds, particularly those involving hydrophobic residues, making it a valuable tool in protein research and engineering.

Pepsin A is defined as a digestive enzyme that is primarily secreted by the chief cells in the stomach's fundic glands. It plays a crucial role in protein catabolism, helping to break down food proteins into smaller peptides during the digestive process. Pepsin A has an optimal pH range of 1.5-2.5 for its enzymatic activity and is activated from its inactive precursor, pepsinogen, upon exposure to acidic conditions in the stomach.

Carboxypeptidases are a group of enzymes that catalyze the cleavage of peptide bonds at the carboxyl-terminal end of polypeptides or proteins. They specifically remove the last amino acid residue from the protein chain, provided that it has a free carboxyl group and is not blocked by another chemical group. Carboxypeptidases are classified into two main types based on their catalytic mechanism: serine carboxypeptidases and metallo-carboxypeptidases.

Serine carboxypeptidases, also known as chymotrypsin C or carboxypeptidase C, use a serine residue in their active site to catalyze the hydrolysis of peptide bonds. They are found in various organisms, including animals and bacteria.

Metallo-carboxypeptidases, on the other hand, require a metal ion (usually zinc) for their catalytic activity. They can be further divided into several subtypes based on their structure and substrate specificity. For example, carboxypeptidase A prefers to cleave hydrophobic amino acids from the carboxyl-terminal end of proteins, while carboxypeptidase B specifically removes basic residues (lysine or arginine).

Carboxypeptidases have important roles in various biological processes, such as protein maturation, digestion, and regulation of blood pressure. Dysregulation of these enzymes has been implicated in several diseases, including cancer, neurodegenerative disorders, and cardiovascular disease.

Molecular weight, also known as molecular mass, is the mass of a molecule. It is expressed in units of atomic mass units (amu) or daltons (Da). Molecular weight is calculated by adding up the atomic weights of each atom in a molecule. It is a useful property in chemistry and biology, as it can be used to determine the concentration of a substance in a solution, or to calculate the amount of a substance that will react with another in a chemical reaction.

Molecular sequence data refers to the specific arrangement of molecules, most commonly nucleotides in DNA or RNA, or amino acids in proteins, that make up a biological macromolecule. This data is generated through laboratory techniques such as sequencing, and provides information about the exact order of the constituent molecules. This data is crucial in various fields of biology, including genetics, evolution, and molecular biology, allowing for comparisons between different organisms, identification of genetic variations, and studies of gene function and regulation.

Peptide mapping is a technique used in proteomics and analytical chemistry to analyze and identify the sequence and structure of peptides or proteins. This method involves breaking down a protein into smaller peptide fragments using enzymatic or chemical digestion, followed by separation and identification of these fragments through various analytical techniques such as liquid chromatography (LC) and mass spectrometry (MS).

The resulting peptide map serves as a "fingerprint" of the protein, providing information about its sequence, modifications, and structure. Peptide mapping can be used for a variety of applications, including protein identification, characterization of post-translational modifications, and monitoring of protein degradation or cleavage.

In summary, peptide mapping is a powerful tool in proteomics that enables the analysis and identification of proteins and their modifications at the peptide level.

Electrophoresis, polyacrylamide gel (EPG) is a laboratory technique used to separate and analyze complex mixtures of proteins or nucleic acids (DNA or RNA) based on their size and electrical charge. This technique utilizes a matrix made of cross-linked polyacrylamide, a type of gel, which provides a stable and uniform environment for the separation of molecules.

In this process:

1. The polyacrylamide gel is prepared by mixing acrylamide monomers with a cross-linking agent (bis-acrylamide) and a catalyst (ammonium persulfate) in the presence of a buffer solution.
2. The gel is then poured into a mold and allowed to polymerize, forming a solid matrix with uniform pore sizes that depend on the concentration of acrylamide used. Higher concentrations result in smaller pores, providing better resolution for separating smaller molecules.
3. Once the gel has set, it is placed in an electrophoresis apparatus containing a buffer solution. Samples containing the mixture of proteins or nucleic acids are loaded into wells on the top of the gel.
4. An electric field is applied across the gel, causing the negatively charged molecules to migrate towards the positive electrode (anode) while positively charged molecules move toward the negative electrode (cathode). The rate of migration depends on the size, charge, and shape of the molecules.
5. Smaller molecules move faster through the gel matrix and will migrate farther from the origin compared to larger molecules, resulting in separation based on size. Proteins and nucleic acids can be selectively stained after electrophoresis to visualize the separated bands.

EPG is widely used in various research fields, including molecular biology, genetics, proteomics, and forensic science, for applications such as protein characterization, DNA fragment analysis, cloning, mutation detection, and quality control of nucleic acid or protein samples.

High-performance liquid chromatography (HPLC) is a type of chromatography that separates and analyzes compounds based on their interactions with a stationary phase and a mobile phase under high pressure. The mobile phase, which can be a gas or liquid, carries the sample mixture through a column containing the stationary phase.

In HPLC, the mobile phase is a liquid, and it is pumped through the column at high pressures (up to several hundred atmospheres) to achieve faster separation times and better resolution than other types of liquid chromatography. The stationary phase can be a solid or a liquid supported on a solid, and it interacts differently with each component in the sample mixture, causing them to separate as they travel through the column.

HPLC is widely used in analytical chemistry, pharmaceuticals, biotechnology, and other fields to separate, identify, and quantify compounds present in complex mixtures. It can be used to analyze a wide range of substances, including drugs, hormones, vitamins, pigments, flavors, and pollutants. HPLC is also used in the preparation of pure samples for further study or use.

Gel chromatography is a type of liquid chromatography that separates molecules based on their size or molecular weight. It uses a stationary phase that consists of a gel matrix made up of cross-linked polymers, such as dextran, agarose, or polyacrylamide. The gel matrix contains pores of various sizes, which allow smaller molecules to penetrate deeper into the matrix while larger molecules are excluded.

In gel chromatography, a mixture of molecules is loaded onto the top of the gel column and eluted with a solvent that moves down the column by gravity or pressure. As the sample components move down the column, they interact with the gel matrix and get separated based on their size. Smaller molecules can enter the pores of the gel and take longer to elute, while larger molecules are excluded from the pores and elute more quickly.

Gel chromatography is commonly used to separate and purify proteins, nucleic acids, and other biomolecules based on their size and molecular weight. It is also used in the analysis of polymers, colloids, and other materials with a wide range of applications in chemistry, biology, and medicine.

Collagen is the most abundant protein in the human body, and it is a major component of connective tissues such as tendons, ligaments, skin, and bones. Collagen provides structure and strength to these tissues and helps them to withstand stretching and tension. It is made up of long chains of amino acids, primarily glycine, proline, and hydroxyproline, which are arranged in a triple helix structure. There are at least 16 different types of collagen found in the body, each with slightly different structures and functions. Collagen is important for maintaining the integrity and health of tissues throughout the body, and it has been studied for its potential therapeutic uses in various medical conditions.

Ethidium is a fluorescent, intercalating compound that is often used in molecular biology to stain DNA. When ethidium bromide, a common form of ethidium, binds to DNA, it causes the DNA to fluoresce brightly under ultraviolet light. This property makes it useful for visualizing DNA bands on gels, such as agarose or polyacrylamide gels, during techniques like gel electrophoresis.

It is important to note that ethidium bromide is a mutagen and should be handled with care. It can cause damage to DNA, which can lead to mutations, and it can also be harmful if inhaled or ingested. Therefore, appropriate safety precautions must be taken when working with this compound.

In the context of medicine, "chemistry" often refers to the field of study concerned with the properties, composition, and structure of elements and compounds, as well as their reactions with one another. It is a fundamental science that underlies much of modern medicine, including pharmacology (the study of drugs), toxicology (the study of poisons), and biochemistry (the study of the chemical processes that occur within living organisms).

In addition to its role as a basic science, chemistry is also used in medical testing and diagnosis. For example, clinical chemistry involves the analysis of bodily fluids such as blood and urine to detect and measure various substances, such as glucose, cholesterol, and electrolytes, that can provide important information about a person's health status.

Overall, chemistry plays a critical role in understanding the mechanisms of diseases, developing new treatments, and improving diagnostic tests and techniques.

Chemical phenomena refer to the changes and interactions that occur at the molecular or atomic level when chemicals are involved. These phenomena can include chemical reactions, in which one or more substances (reactants) are converted into different substances (products), as well as physical properties that change as a result of chemical interactions, such as color, state of matter, and solubility. Chemical phenomena can be studied through various scientific disciplines, including chemistry, biochemistry, and physics.

In the context of medical and biological sciences, a "binding site" refers to a specific location on a protein, molecule, or cell where another molecule can attach or bind. This binding interaction can lead to various functional changes in the original protein or molecule. The other molecule that binds to the binding site is often referred to as a ligand, which can be a small molecule, ion, or even another protein.

The binding between a ligand and its target binding site can be specific and selective, meaning that only certain ligands can bind to particular binding sites with high affinity. This specificity plays a crucial role in various biological processes, such as signal transduction, enzyme catalysis, or drug action.

In the case of drug development, understanding the location and properties of binding sites on target proteins is essential for designing drugs that can selectively bind to these sites and modulate protein function. This knowledge can help create more effective and safer therapeutic options for various diseases.

Macromolecular substances, also known as macromolecules, are large, complex molecules made up of repeating subunits called monomers. These substances are formed through polymerization, a process in which many small molecules combine to form a larger one. Macromolecular substances can be naturally occurring, such as proteins, DNA, and carbohydrates, or synthetic, such as plastics and synthetic fibers.

In the context of medicine, macromolecular substances are often used in the development of drugs and medical devices. For example, some drugs are designed to bind to specific macromolecules in the body, such as proteins or DNA, in order to alter their function and produce a therapeutic effect. Additionally, macromolecular substances may be used in the creation of medical implants, such as artificial joints and heart valves, due to their strength and durability.

It is important for healthcare professionals to have an understanding of macromolecular substances and how they function in the body, as this knowledge can inform the development and use of medical treatments.

"Cattle" is a term used in the agricultural and veterinary fields to refer to domesticated animals of the genus *Bos*, primarily *Bos taurus* (European cattle) and *Bos indicus* (Zebu). These animals are often raised for meat, milk, leather, and labor. They are also known as bovines or cows (for females), bulls (intact males), and steers/bullocks (castrated males). However, in a strict medical definition, "cattle" does not apply to humans or other animals.

Peptides are short chains of amino acid residues linked by covalent bonds, known as peptide bonds. They are formed when two or more amino acids are joined together through a condensation reaction, which results in the elimination of a water molecule and the formation of an amide bond between the carboxyl group of one amino acid and the amino group of another.

Peptides can vary in length from two to about fifty amino acids, and they are often classified based on their size. For example, dipeptides contain two amino acids, tripeptides contain three, and so on. Oligopeptides typically contain up to ten amino acids, while polypeptides can contain dozens or even hundreds of amino acids.

Peptides play many important roles in the body, including serving as hormones, neurotransmitters, enzymes, and antibiotics. They are also used in medical research and therapeutic applications, such as drug delivery and tissue engineering.

Ion exchange chromatography is a type of chromatography technique used to separate and analyze charged molecules (ions) based on their ability to exchange bound ions in a solid resin or gel with ions of similar charge in the mobile phase. The stationary phase, often called an ion exchanger, contains fixed ated functional groups that can attract counter-ions of opposite charge from the sample mixture.

In this technique, the sample is loaded onto an ion exchange column containing the charged resin or gel. As the sample moves through the column, ions in the sample compete for binding sites on the stationary phase with ions already present in the column. The ions that bind most strongly to the stationary phase will elute (come off) slower than those that bind more weakly.

Ion exchange chromatography can be performed using either cation exchangers, which exchange positive ions (cations), or anion exchangers, which exchange negative ions (anions). The pH and ionic strength of the mobile phase can be adjusted to control the binding and elution of specific ions.

Ion exchange chromatography is widely used in various applications such as water treatment, protein purification, and chemical analysis.

Peptide hydrolases, also known as proteases or peptidases, are a group of enzymes that catalyze the hydrolysis of peptide bonds in proteins and peptides. They play a crucial role in various biological processes such as protein degradation, digestion, cell signaling, and regulation of various physiological functions. Based on their catalytic mechanism and the specificity for the peptide bond, they are classified into several types, including serine proteases, cysteine proteases, aspartic proteases, and metalloproteases. These enzymes have important clinical applications in the diagnosis and treatment of various diseases, such as cancer, viral infections, and inflammatory disorders.

Disulfides are a type of organic compound that contains a sulfur-sulfur bond. In the context of biochemistry and medicine, disulfide bonds are often found in proteins, where they play a crucial role in maintaining their three-dimensional structure and function. These bonds form when two sulfhydryl groups (-SH) on cysteine residues within a protein molecule react with each other, releasing a molecule of water and creating a disulfide bond (-S-S-) between the two cysteines. Disulfide bonds can be reduced back to sulfhydryl groups by various reducing agents, which is an important process in many biological reactions. The formation and reduction of disulfide bonds are critical for the proper folding, stability, and activity of many proteins, including those involved in various physiological processes and diseases.

I believe there may be some confusion in your question. "Rabbits" is a common name used to refer to the Lagomorpha species, particularly members of the family Leporidae. They are small mammals known for their long ears, strong legs, and quick reproduction.

However, if you're referring to "rabbits" in a medical context, there is a term called "rabbit syndrome," which is a rare movement disorder characterized by repetitive, involuntary movements of the fingers, resembling those of a rabbit chewing. It is also known as "finger-chewing chorea." This condition is usually associated with certain medications, particularly antipsychotics, and typically resolves when the medication is stopped or adjusted.

Phosphoglycerate Kinase (PGK) is an enzyme that plays a crucial role in the glycolytic pathway, which is a series of reactions that convert glucose into pyruvate, producing ATP and NADH as energy-rich compounds. PGK catalyzes the conversion of 1,3-bisphosphoglycerate (1,3-BPG) to 3-phosphoglycerate (3-PG), concomitantly transferring a phosphate group to ADP to form ATP. This reaction is the fourth step in the glycolytic pathway and is reversible under certain conditions.

In humans, there are two isoforms of PGK: PGK1 and PGK2. PGK1 is widely expressed in various tissues, while PGK2 is primarily found in sperm cells. Deficiencies or mutations in the PGK1 gene can lead to a rare metabolic disorder called Phosphoglycerate Kinase Deficiency (PGKD), which can present with hemolytic anemia and neurological symptoms.

Affinity labels are chemical probes or reagents that can selectively and covalently bind to a specific protein or biomolecule based on its biological function or activity. These labels contain a functional group that interacts with the target molecule, often through non-covalent interactions such as hydrogen bonding, van der Waals forces, or ionic bonds. Once bound, the label then forms a covalent bond with the target molecule, allowing for its isolation and further study.

Affinity labels are commonly used in biochemistry and molecular biology research to identify and characterize specific proteins, enzymes, or receptors. They can be designed to bind to specific active sites, binding pockets, or other functional regions of a protein, allowing researchers to study the structure-function relationships of these molecules.

One example of an affinity label is a substrate analogue that contains a chemically reactive group. This type of affinity label can be used to identify and characterize enzymes by binding to their active sites and forming a covalent bond with the enzyme. The labeled enzyme can then be purified and analyzed to determine its structure, function, and mechanism of action.

Overall, affinity labels are valuable tools for studying the properties and functions of biological molecules in vitro and in vivo.

Protein conformation refers to the specific three-dimensional shape that a protein molecule assumes due to the spatial arrangement of its constituent amino acid residues and their associated chemical groups. This complex structure is determined by several factors, including covalent bonds (disulfide bridges), hydrogen bonds, van der Waals forces, and ionic bonds, which help stabilize the protein's unique conformation.

Protein conformations can be broadly classified into two categories: primary, secondary, tertiary, and quaternary structures. The primary structure represents the linear sequence of amino acids in a polypeptide chain. The secondary structure arises from local interactions between adjacent amino acid residues, leading to the formation of recurring motifs such as α-helices and β-sheets. Tertiary structure refers to the overall three-dimensional folding pattern of a single polypeptide chain, while quaternary structure describes the spatial arrangement of multiple folded polypeptide chains (subunits) that interact to form a functional protein complex.

Understanding protein conformation is crucial for elucidating protein function, as the specific three-dimensional shape of a protein directly influences its ability to interact with other molecules, such as ligands, nucleic acids, or other proteins. Any alterations in protein conformation due to genetic mutations, environmental factors, or chemical modifications can lead to loss of function, misfolding, aggregation, and disease states like neurodegenerative disorders and cancer.

Endopeptidases are a type of enzyme that breaks down proteins by cleaving peptide bonds inside the polypeptide chain. They are also known as proteinases or endoproteinases. These enzymes work within the interior of the protein molecule, cutting it at specific points along its length, as opposed to exopeptidases, which remove individual amino acids from the ends of the protein chain.

Endopeptidases play a crucial role in various biological processes, such as digestion, blood coagulation, and programmed cell death (apoptosis). They are classified based on their catalytic mechanism and the structure of their active site. Some examples of endopeptidase families include serine proteases, cysteine proteases, aspartic proteases, and metalloproteases.

It is important to note that while endopeptidases are essential for normal physiological functions, they can also contribute to disease processes when their activity is unregulated or misdirected. For instance, excessive endopeptidase activity has been implicated in the pathogenesis of neurodegenerative disorders, cancer, and inflammatory conditions.

Lathyrism is a neurological disorder caused by the consumption of large amounts of food sources containing a toxin called β-N-oxalyl-L-α,β-diaminopropionic acid (ODAP), which is found in certain legumes of the genus Lathyrus, particularly in grass peas (L. sativus). This disorder is characterized by the irreversible spastic paralysis of lower limbs due to damage in the upper motor neurons of the spinal cord. The onset and severity of lathyrism depend on the amount and duration of ODAP-containing food intake, with higher doses and longer exposure leading to more severe symptoms. Lathyrism is more prevalent in regions where grass peas are a staple food and access to diverse nutrition is limited.

Brominated hydrocarbons are organic compounds that contain carbon (C), hydrogen (H), and bromine (Br) atoms. These chemicals are formed by replacing one or more hydrogen atoms in a hydrocarbon molecule with bromine atoms. Depending on the number and arrangement of bromine atoms, these compounds can have different properties and uses.

Some brominated hydrocarbons occur naturally, while others are synthesized for various applications. They can be found in consumer products like flame retardants, fumigants, refrigerants, and solvents. However, some brominated hydrocarbons have been linked to health and environmental concerns, leading to regulations on their production and use.

Examples of brominated hydrocarbons include:

1. Methyl bromide (CH3Br): A colorless gas used as a pesticide and fumigant. It is also a naturally occurring compound in the atmosphere, contributing to ozone depletion.
2. Polybrominated diphenyl ethers (PBDEs): A group of chemicals used as flame retardants in various consumer products, such as electronics, furniture, and textiles. They have been linked to neurodevelopmental issues, endocrine disruption, and cancer.
3. Bromoform (CHBr3) and dibromomethane (CH2Br2): These compounds are used in chemical synthesis, as solvents, and in water treatment. They can also be found in some natural sources like seaweed or marine organisms.
4. Hexabromocyclododecane (HBCD): A flame retardant used in expanded polystyrene foam for building insulation and in high-impact polystyrene products. HBCD has been linked to reproductive and developmental toxicity, as well as endocrine disruption.

It is essential to handle brominated hydrocarbons with care due to their potential health and environmental risks. Proper storage, use, and disposal of these chemicals are crucial to minimize exposure and reduce negative impacts.

Photoaffinity labels are molecules that, upon exposure to light, form covalent bonds with nearby proteins or other biomolecules. These labels typically contain a reactive group that becomes highly reactive after photoactivation, allowing for the specific and irreversible labeling of proteins in their native environment. This technique is widely used in molecular biology research to study protein-protein interactions, protein structure, and protein function. The labeled proteins can then be identified and analyzed using various methods such as gel electrophoresis, mass spectrometry, or microscopy.

Procollagen is the precursor protein of collagen, which is a major structural protein in the extracellular matrix of various connective tissues, such as tendons, ligaments, skin, and bones. Procollagen is synthesized inside the cell (in the rough endoplasmic reticulum) and then processed by enzymes to remove specific segments, resulting in the formation of tropocollagen, which are the basic units of collagen fibrils.

Procollagen consists of three polypeptide chains (two alpha-1 and one alpha-2 chain), each containing a central triple-helical domain flanked by non-helical regions at both ends. These non-helical regions, called propeptides, are cleaved off during the processing of procollagen to tropocollagen, allowing the individual collagen molecules to align and form fibrils through covalent cross-linking.

Abnormalities in procollagen synthesis or processing can lead to various connective tissue disorders, such as osteogenesis imperfecta (brittle bone disease) and Ehlers-Danlos syndrome (a group of disorders characterized by joint hypermobility, skin hyperextensibility, and tissue fragility).

Leucyl aminopeptidase (LAP) is an enzyme that plays a role in the metabolism and breakdown of proteins. It is found in various tissues and organs throughout the body, including the small intestine, liver, and kidneys. LAP specifically catalyzes the removal of leucine, a type of amino acid, from the N-terminus (the beginning) of peptides and proteins. This enzyme is important for the proper digestion and absorption of dietary proteins, as well as for the regulation of various physiological processes in the body. Abnormal levels or activity of LAP have been implicated in certain diseases, such as cancer and liver disease.

Ipratropium is an anticholinergic bronchodilator medication that is often used to treat respiratory conditions such as chronic obstructive pulmonary disease (COPD) and asthma. It works by blocking the action of acetylcholine, a chemical messenger in the body that causes muscles around the airways to tighten and narrow. By preventing this effect, ipratropium helps to relax the muscles around the airways, making it easier to breathe.

Ipratropium is available in several forms, including an aerosol spray, nebulizer solution, and dry powder inhaler. It is typically used in combination with other respiratory medications, such as beta-agonists or corticosteroids, to provide more effective relief of symptoms. Common side effects of ipratropium include dry mouth, throat irritation, and headache.

Dansyl compounds are fluorescent compounds that contain a dansyl group, which is a chemical group made up of a sulfonated derivative of dimethylaminonaphthalene. These compounds are often used as tracers in biochemical and medical research because they emit bright fluorescence when excited by ultraviolet or visible light. This property makes them useful for detecting and quantifying various biological molecules, such as amino acids, peptides, and proteins, in a variety of assays and techniques, including high-performance liquid chromatography (HPLC), thin-layer chromatography (TLC), and fluorescence microscopy.

The dansyl group can be attached to biological molecules through chemical reactions that involve the formation of covalent bonds between the sulfonate group in the dansyl compound and amino, thiol, or hydroxyl groups in the target molecule. The resulting dansylated molecules can then be detected and analyzed using various techniques.

Dansyl compounds are known for their high sensitivity, stability, and versatility, making them valuable tools in a wide range of research applications. However, it is important to note that the use of dansyl compounds requires careful handling and appropriate safety precautions, as they can be hazardous if mishandled or ingested.

'Escherichia coli' (E. coli) is a type of gram-negative, facultatively anaerobic, rod-shaped bacterium that commonly inhabits the intestinal tract of humans and warm-blooded animals. It is a member of the family Enterobacteriaceae and one of the most well-studied prokaryotic model organisms in molecular biology.

While most E. coli strains are harmless and even beneficial to their hosts, some serotypes can cause various forms of gastrointestinal and extraintestinal illnesses in humans and animals. These pathogenic strains possess virulence factors that enable them to colonize and damage host tissues, leading to diseases such as diarrhea, urinary tract infections, pneumonia, and sepsis.

E. coli is a versatile organism with remarkable genetic diversity, which allows it to adapt to various environmental niches. It can be found in water, soil, food, and various man-made environments, making it an essential indicator of fecal contamination and a common cause of foodborne illnesses. The study of E. coli has contributed significantly to our understanding of fundamental biological processes, including DNA replication, gene regulation, and protein synthesis.

Methionine is an essential amino acid, which means that it cannot be synthesized by the human body and must be obtained through the diet. It plays a crucial role in various biological processes, including:

1. Protein synthesis: Methionine is one of the building blocks of proteins, helping to create new proteins and maintain the structure and function of cells.
2. Methylation: Methionine serves as a methyl group donor in various biochemical reactions, which are essential for DNA synthesis, gene regulation, and neurotransmitter production.
3. Antioxidant defense: Methionine can be converted to cysteine, which is involved in the formation of glutathione, a potent antioxidant that helps protect cells from oxidative damage.
4. Homocysteine metabolism: Methionine is involved in the conversion of homocysteine back to methionine through a process called remethylation, which is essential for maintaining normal homocysteine levels and preventing cardiovascular disease.
5. Fat metabolism: Methionine helps facilitate the breakdown and metabolism of fats in the body.

Foods rich in methionine include meat, fish, dairy products, eggs, and some nuts and seeds.

Galactosidases are a group of enzymes that catalyze the hydrolysis of galactose-containing sugars, specifically at the beta-glycosidic bond. There are several types of galactosidases, including:

1. Beta-galactosidase: This is the most well-known type of galactosidase and it catalyzes the hydrolysis of lactose into glucose and galactose. It has important roles in various biological processes, such as lactose metabolism in animals and cell wall biosynthesis in plants.
2. Alpha-galactosidase: This enzyme catalyzes the hydrolysis of alpha-galactosides, which are found in certain plant-derived foods like legumes. A deficiency in this enzyme can lead to a genetic disorder called Fabry disease.
3. N-acetyl-beta-glucosaminidase: This enzyme is also known as hexosaminidase and it catalyzes the hydrolysis of N-acetyl-beta-D-glucosamine residues from glycoproteins, glycolipids, and other complex carbohydrates.

Galactosidases are widely used in various industrial applications, such as food processing, biotechnology, and biofuel production. They also have potential therapeutic uses, such as in the treatment of lysosomal storage disorders like Fabry disease.

An epitope is a specific region on the surface of an antigen (a molecule that can trigger an immune response) that is recognized by an antibody, B-cell receptor, or T-cell receptor. It is also commonly referred to as an antigenic determinant. Epitopes are typically composed of linear amino acid sequences or conformational structures made up of discontinuous amino acids in the antigen. They play a crucial role in the immune system's ability to differentiate between self and non-self molecules, leading to the targeted destruction of foreign substances like viruses and bacteria. Understanding epitopes is essential for developing vaccines, diagnostic tests, and immunotherapies.

"Maleate" is not a medical term in and of itself, but it is a chemical compound that can be found in some medications. Maleic acid or its salts (maleates) are used as a keratolytic agent in topical medications, which means they help to break down and remove dead skin cells. They can also be used as a preservative or a buffering agent in various pharmaceutical preparations.

Maleic acid is a type of organic compound known as a dicarboxylic acid, which contains two carboxyl groups. In the case of maleic acid, these carboxyl groups are located on a single carbon atom, which makes it a cis-conjugated diacid. This structural feature gives maleic acid unique chemical properties that can be useful in various pharmaceutical and industrial applications.

It's worth noting that maleic acid and its salts should not be confused with "maleate" as a gender-specific term, which refers to something related to or characteristic of males.

Hydroxylysine is a modified form of the amino acid lysine, which is formed by the addition of a hydroxyl group (-OH) to the lysine molecule. This process is known as hydroxylation and is catalyzed by the enzyme lysyl hydroxylase.

In the human body, hydroxylysine is an important component of collagen, which is a protein that provides structure and strength to tissues such as skin, tendons, ligaments, and bones. Hydroxylysine helps to stabilize the triple-helix structure of collagen by forming cross-links between individual collagen molecules.

Abnormalities in hydroxylysine metabolism can lead to various connective tissue disorders, such as Ehlers-Danlos syndrome and osteogenesis imperfecta, which are characterized by joint hypermobility, skin fragility, and bone fractures.

Affinity chromatography is a type of chromatography technique used in biochemistry and molecular biology to separate and purify proteins based on their biological characteristics, such as their ability to bind specifically to certain ligands or molecules. This method utilizes a stationary phase that is coated with a specific ligand (e.g., an antibody, antigen, receptor, or enzyme) that selectively interacts with the target protein in a sample.

The process typically involves the following steps:

1. Preparation of the affinity chromatography column: The stationary phase, usually a solid matrix such as agarose beads or magnetic beads, is modified by covalently attaching the ligand to its surface.
2. Application of the sample: The protein mixture is applied to the top of the affinity chromatography column, allowing it to flow through the stationary phase under gravity or pressure.
3. Binding and washing: As the sample flows through the column, the target protein selectively binds to the ligand on the stationary phase, while other proteins and impurities pass through. The column is then washed with a suitable buffer to remove any unbound proteins and contaminants.
4. Elution of the bound protein: The target protein can be eluted from the column using various methods, such as changing the pH, ionic strength, or polarity of the buffer, or by introducing a competitive ligand that displaces the bound protein.
5. Collection and analysis: The eluted protein fraction is collected and analyzed for purity and identity, often through techniques like SDS-PAGE or mass spectrometry.

Affinity chromatography is a powerful tool in biochemistry and molecular biology due to its high selectivity and specificity, enabling the efficient isolation of target proteins from complex mixtures. However, it requires careful consideration of the binding affinity between the ligand and the protein, as well as optimization of the elution conditions to minimize potential damage or denaturation of the purified protein.

Iodobenzoates are organic compounds that consist of a benzoic acid molecule with an iodine atom substituted at the carboxyl group. Specifically, an iodobenzoate is an ester derived from benzoic acid and iodine, in which the hydrogen atom of the carboxylic acid group (-COOH) has been replaced by an iodine atom.

The general formula for an iodobenzoate can be represented as C6H4(IO)CO2R, where R represents an alkyl or aryl group. Iodobenzoates have various applications in organic synthesis and pharmaceuticals, including the production of dyes, drugs, and other chemical intermediates.

It's worth noting that iodobenzoates are not a medical condition or diagnosis but rather a class of chemical compounds with potential uses in medical research and therapeutics.

Hydroxylamine is not a medical term, but it is a chemical compound with the formula NH2OH. It's used in some industrial processes and can also be found as a byproduct of certain metabolic reactions in the body. In a medical context, exposure to high levels of hydroxylamine may cause irritation to the skin, eyes, and respiratory tract, and it may have harmful effects on the nervous system and blood if ingested or absorbed in large amounts. However, it is not a substance that is commonly encountered or monitored in medical settings.

Cysteine is a semi-essential amino acid, which means that it can be produced by the human body under normal circumstances, but may need to be obtained from external sources in certain conditions such as illness or stress. Its chemical formula is HO2CCH(NH2)CH2SH, and it contains a sulfhydryl group (-SH), which allows it to act as a powerful antioxidant and participate in various cellular processes.

Cysteine plays important roles in protein structure and function, detoxification, and the synthesis of other molecules such as glutathione, taurine, and coenzyme A. It is also involved in wound healing, immune response, and the maintenance of healthy skin, hair, and nails.

Cysteine can be found in a variety of foods, including meat, poultry, fish, dairy products, eggs, legumes, nuts, seeds, and some grains. It is also available as a dietary supplement and can be used in the treatment of various medical conditions such as liver disease, bronchitis, and heavy metal toxicity. However, excessive intake of cysteine may have adverse effects on health, including gastrointestinal disturbances, nausea, vomiting, and headaches.

Carbohydrates are a major nutrient class consisting of organic compounds that primarily contain carbon, hydrogen, and oxygen atoms. They are classified as saccharides, which include monosaccharides (simple sugars), disaccharides (double sugars), oligosaccharides (short-chain sugars), and polysaccharides (complex carbohydrates).

Monosaccharides, such as glucose, fructose, and galactose, are the simplest form of carbohydrates. They consist of a single sugar molecule that cannot be broken down further by hydrolysis. Disaccharides, like sucrose (table sugar), lactose (milk sugar), and maltose (malt sugar), are formed from two monosaccharide units joined together.

Oligosaccharides contain a small number of monosaccharide units, typically less than 20, while polysaccharides consist of long chains of hundreds to thousands of monosaccharide units. Polysaccharides can be further classified into starch (found in plants), glycogen (found in animals), and non-starchy polysaccharides like cellulose, chitin, and pectin.

Carbohydrates play a crucial role in providing energy to the body, with glucose being the primary source of energy for most cells. They also serve as structural components in plants (cellulose) and animals (chitin), participate in various metabolic processes, and contribute to the taste, texture, and preservation of foods.

Species specificity is a term used in the field of biology, including medicine, to refer to the characteristic of a biological entity (such as a virus, bacterium, or other microorganism) that allows it to interact exclusively or preferentially with a particular species. This means that the biological entity has a strong affinity for, or is only able to infect, a specific host species.

For example, HIV is specifically adapted to infect human cells and does not typically infect other animal species. Similarly, some bacterial toxins are species-specific and can only affect certain types of animals or humans. This concept is important in understanding the transmission dynamics and host range of various pathogens, as well as in developing targeted therapies and vaccines.

A muscle is a soft tissue in our body that contracts to produce force and motion. It is composed mainly of specialized cells called muscle fibers, which are bound together by connective tissue. There are three types of muscles: skeletal (voluntary), smooth (involuntary), and cardiac. Skeletal muscles attach to bones and help in movement, while smooth muscles are found within the walls of organs and blood vessels, helping with functions like digestion and circulation. Cardiac muscle is the specific type that makes up the heart, allowing it to pump blood throughout the body.

In the context of medicine and pharmacology, "kinetics" refers to the study of how a drug moves throughout the body, including its absorption, distribution, metabolism, and excretion (often abbreviated as ADME). This field is called "pharmacokinetics."

1. Absorption: This is the process of a drug moving from its site of administration into the bloodstream. Factors such as the route of administration (e.g., oral, intravenous, etc.), formulation, and individual physiological differences can affect absorption.

2. Distribution: Once a drug is in the bloodstream, it gets distributed throughout the body to various tissues and organs. This process is influenced by factors like blood flow, protein binding, and lipid solubility of the drug.

3. Metabolism: Drugs are often chemically modified in the body, typically in the liver, through processes known as metabolism. These changes can lead to the formation of active or inactive metabolites, which may then be further distributed, excreted, or undergo additional metabolic transformations.

4. Excretion: This is the process by which drugs and their metabolites are eliminated from the body, primarily through the kidneys (urine) and the liver (bile).

Understanding the kinetics of a drug is crucial for determining its optimal dosing regimen, potential interactions with other medications or foods, and any necessary adjustments for special populations like pediatric or geriatric patients, or those with impaired renal or hepatic function.

The MNSs blood group system is one of the human blood group systems, which is a classification of blood types based on the presence or absence of specific antigens on the surface of red blood cells (RBCs). This system is named after the first two letters of the surnames of the discoverers, Landsteiner and Levine, and the "s" stands for "slight."

The MNSs system includes three main antigens: M, N, and S. The M and N antigens are found on nearly all individuals, except for those who are genetically predisposed to lack both M and N antigens (M+N- or M-N-). These individuals have the "null" phenotype, also known as the "Ms" phenotype.

The S antigen is present in about 80% of people, while the s antigen is found in approximately 20% of people. The presence or absence of these antigens determines an individual's MNSs blood type. There are eight main MNSs blood types: M, N, MN, MS, NS, M+m, N+s, and M+N+S+s+.

The clinical significance of the MNSs system is relatively low compared to other blood group systems like ABO and Rh. However, it can still play a role in transfusion medicine, as antibodies against MNSs antigens may cause hemolytic transfusion reactions or hemolytic disease of the newborn (HDN) in rare cases. Therefore, it is essential to consider the MNSs blood group when performing pretransfusion testing and during pregnancy to ensure compatible blood products and prevent complications.

Cyanides are a group of chemical compounds that contain the cyano group, -CN, which consists of a carbon atom triple-bonded to a nitrogen atom. They are highly toxic and can cause rapid death due to the inhibition of cellular respiration. Cyanide ions (CN-) bind to the ferric iron in cytochrome c oxidase, a crucial enzyme in the electron transport chain, preventing the flow of electrons and the production of ATP, leading to cellular asphyxiation.

Common sources of cyanides include industrial chemicals such as hydrogen cyanide (HCN) and potassium cyanide (KCN), as well as natural sources like certain fruits, nuts, and plants. Exposure to high levels of cyanides can occur through inhalation, ingestion, or skin absorption, leading to symptoms such as headache, dizziness, nausea, vomiting, rapid heartbeat, seizures, coma, and ultimately death. Treatment for cyanide poisoning typically involves the use of antidotes that bind to cyanide ions and convert them into less toxic forms, such as thiosulfate and rhodanese.

Hydroxylamines are organic compounds that contain a hydroxy group (-OH) and an amino group (-NH2) in their structure. More specifically, they have the functional group R-N-OH, where R represents a carbon-containing radical. Hydroxylamines can be considered as derivatives of ammonia (NH3), where one hydrogen atom is replaced by a hydroxy group.

These compounds are important in organic chemistry and biochemistry due to their ability to act as reducing agents, nitrogen donors, and intermediates in various chemical reactions. They can be found in some natural substances and are also synthesized for use in pharmaceuticals, agrochemicals, and other industrial applications.

Examples of hydroxylamines include:

* Hydroxylamine (NH2OH) itself, which is a colorless liquid at room temperature with an odor similar to ammonia.
* N-Methylhydroxylamine (CH3NHOH), which is a solid that can be used as a reducing agent and a nucleophile in organic synthesis.
* Phenylhydroxylamine (C6H5NHOH), which is a solid used as an intermediate in the production of dyes, pharmaceuticals, and other chemicals.

It's important to note that hydroxylamines can be unstable and potentially hazardous, so they should be handled with care during laboratory work or industrial processes.

Papain is defined as a proteolytic enzyme that is derived from the latex of the papaya tree (Carica papaya). It has the ability to break down other proteins into smaller peptides or individual amino acids. Papain is widely used in various industries, including the food industry for tenderizing meat and brewing beer, as well as in the medical field for its digestive and anti-inflammatory properties.

In medicine, papain is sometimes used topically to help heal burns, wounds, and skin ulcers. It can also be taken orally to treat indigestion, parasitic infections, and other gastrointestinal disorders. However, its use as a medical treatment is not widely accepted and more research is needed to establish its safety and efficacy.

Serine endopeptidases are a type of enzymes that cleave peptide bonds within proteins (endopeptidases) and utilize serine as the nucleophilic amino acid in their active site for catalysis. These enzymes play crucial roles in various biological processes, including digestion, blood coagulation, and programmed cell death (apoptosis). Examples of serine endopeptidases include trypsin, chymotrypsin, thrombin, and elastase.

Chromatography is a technique used in analytical chemistry for the separation, identification, and quantification of the components of a mixture. It is based on the differential distribution of the components of a mixture between a stationary phase and a mobile phase. The stationary phase can be a solid or liquid, while the mobile phase is a gas, liquid, or supercritical fluid that moves through the stationary phase carrying the sample components.

The interaction between the sample components and the stationary and mobile phases determines how quickly each component will move through the system. Components that interact more strongly with the stationary phase will move more slowly than those that interact more strongly with the mobile phase. This difference in migration rates allows for the separation of the components, which can then be detected and quantified.

There are many different types of chromatography, including paper chromatography, thin-layer chromatography (TLC), gas chromatography (GC), liquid chromatography (LC), and high-performance liquid chromatography (HPLC). Each type has its own strengths and weaknesses, and is best suited for specific applications.

In summary, chromatography is a powerful analytical technique used to separate, identify, and quantify the components of a mixture based on their differential distribution between a stationary phase and a mobile phase.

A base sequence in the context of molecular biology refers to the specific order of nucleotides in a DNA or RNA molecule. In DNA, these nucleotides are adenine (A), guanine (G), cytosine (C), and thymine (T). In RNA, uracil (U) takes the place of thymine. The base sequence contains genetic information that is transcribed into RNA and ultimately translated into proteins. It is the exact order of these bases that determines the genetic code and thus the function of the DNA or RNA molecule.

Electrophoresis is a laboratory technique used in the field of molecular biology and chemistry to separate charged particles, such as DNA, RNA, or proteins, based on their size and charge. This technique uses an electric field to drive the movement of these charged particles through a medium, such as gel or liquid.

In electrophoresis, the sample containing the particles to be separated is placed in a matrix, such as a gel or a capillary tube, and an electric current is applied. The particles in the sample have a net charge, either positive or negative, which causes them to move through the matrix towards the oppositely charged electrode.

The rate at which the particles move through the matrix depends on their size and charge. Larger particles move more slowly than smaller ones, and particles with a higher charge-to-mass ratio move faster than those with a lower charge-to-mass ratio. By comparing the distance that each particle travels in the matrix, researchers can identify and quantify the different components of a mixture.

Electrophoresis has many applications in molecular biology and medicine, including DNA sequencing, genetic fingerprinting, protein analysis, and diagnosis of genetic disorders.

Hydrolysis is a chemical process, not a medical one. However, it is relevant to medicine and biology.

Hydrolysis is the breakdown of a chemical compound due to its reaction with water, often resulting in the formation of two or more simpler compounds. In the context of physiology and medicine, hydrolysis is a crucial process in various biological reactions, such as the digestion of food molecules like proteins, carbohydrates, and fats. Enzymes called hydrolases catalyze these hydrolysis reactions to speed up the breakdown process in the body.

Bromosuccinimide is a chemical compound with the formula C4H2BrNO2S. It is a white crystalline solid that is used as a brominating agent in organic synthesis. Bromosuccinimide is an important reagent for introducing bromine into organic molecules, and it is particularly useful for carrying out selective brominations of unsaturated compounds.

Bromosuccinimide is typically used in solution, and it can be prepared by reacting succinimide with bromine in the presence of a base. It is a relatively stable compound, but it can decompose if heated or if it is exposed to strong oxidizing agents. Bromosuccinimide is not commonly used in medical applications, but it may be encountered in laboratory settings where organic synthesis is performed.

Atropine derivatives are a class of drugs that are chemically related to atropine, an alkaloid found in the nightshade family of plants. These drugs have anticholinergic properties, which means they block the action of the neurotransmitter acetylcholine in the body.

Atropine derivatives can be used for a variety of medical purposes, including:

1. Treating motion sickness and vertigo
2. Dilating the pupils during eye examinations
3. Reducing saliva production during surgical procedures
4. Treating certain types of poisoning, such as organophosphate or nerve gas poisoning
5. Managing symptoms of some neurological disorders, such as Parkinson's disease and myasthenia gravis

Some examples of atropine derivatives include hyoscyamine, scopolamine, and ipratropium. These drugs can have side effects, including dry mouth, blurred vision, constipation, difficulty urinating, and rapid heartbeat. They should be used with caution and under the supervision of a healthcare provider.

Osteogenesis Imperfecta (OI), also known as brittle bone disease, is a group of genetic disorders that mainly affect the bones. It is characterized by bones that break easily, often from little or no apparent cause. This happens because the body produces an insufficient amount of collagen or poor quality collagen, which are crucial for the formation of healthy bones.

The severity of OI can vary greatly, even within the same family. Some people with OI have only a few fractures in their lifetime while others may have hundreds. Other symptoms can include blue or gray sclera (the white part of the eye), hearing loss, short stature, curved or bowed bones, loose joints, and a triangular face shape.

There are several types of OI, each caused by different genetic mutations. Most types of OI are inherited in an autosomal dominant pattern, meaning only one copy of the altered gene is needed to cause the condition. However, some types are inherited in an autosomal recessive pattern, which means that two copies of the altered gene must be present for the condition to occur.

There is no cure for OI, but treatment can help manage symptoms and prevent complications. Treatment may include medication to strengthen bones, physical therapy, bracing, and surgery.

Butylscopolammonium Bromide is an anticholinergic drug, which is used as a smooth muscle relaxant and an anti-spasmodic agent. It works by blocking the action of acetylcholine, a neurotransmitter in the body, on certain types of receptors, leading to relaxation of smooth muscles and reduction of spasms.

This medication is commonly used to treat gastrointestinal disorders such as irritable bowel syndrome, intestinal cramps, and spastic constipation. It may also be used in the management of bladder disorders, including neurogenic bladder and urinary incontinence.

The drug is available in various forms, including tablets, suppositories, and solutions for injection. The dosage and route of administration depend on the specific condition being treated and the patient's overall health status. As with any medication, Butylscopolammonium Bromide can cause side effects, such as dry mouth, blurred vision, dizziness, and constipation. It should be used under the guidance of a healthcare professional to ensure safe and effective treatment.

Sequence homology in nucleic acids refers to the similarity or identity between the nucleotide sequences of two or more DNA or RNA molecules. It is often used as a measure of biological relationship between genes, organisms, or populations. High sequence homology suggests a recent common ancestry or functional constraint, while low sequence homology may indicate a more distant relationship or different functions.

Nucleic acid sequence homology can be determined by various methods such as pairwise alignment, multiple sequence alignment, and statistical analysis. The degree of homology is typically expressed as a percentage of identical or similar nucleotides in a given window of comparison.

It's important to note that the interpretation of sequence homology depends on the biological context and the evolutionary distance between the sequences compared. Therefore, functional and experimental validation is often necessary to confirm the significance of sequence homology.

Immunodiffusion is a laboratory technique used in immunology to detect and measure the presence of specific antibodies or antigens in a sample. It is based on the principle of diffusion, where molecules move from an area of high concentration to an area of low concentration until they reach equilibrium. In this technique, a sample containing an unknown quantity of antigen or antibody is placed in a gel or agar medium that contains a known quantity of antibody or antigen, respectively.

The two substances then diffuse towards each other and form a visible precipitate at the point where they meet and reach equivalence, which indicates the presence and quantity of the specific antigen or antibody in the sample. There are several types of immunodiffusion techniques, including radial immunodiffusion (RID) and double immunodiffusion (Ouchterlony technique). These techniques are widely used in diagnostic laboratories to identify and measure various antigens and antibodies, such as those found in infectious diseases, autoimmune disorders, and allergic reactions.

Crotalid venoms are the toxic secretions produced by the members of the Crotalinae subfamily, also known as pit vipers. This group includes rattlesnakes, cottonmouths (or water moccasins), and copperheads, which are native to the Americas, as well as Old World vipers found in Asia and Europe, such as gaboon vipers and saw-scaled vipers.

Crotalid venoms are complex mixtures of various bioactive molecules, including enzymes, proteins, peptides, and other low molecular weight components. They typically contain a variety of pharmacologically active components, such as hemotoxic and neurotoxic agents, which can cause extensive local tissue damage, coagulopathy, cardiovascular dysfunction, and neuromuscular disorders in the victim.

The composition of crotalid venoms can vary significantly between different species and even among individual specimens within the same species. This variability is influenced by factors such as geographic location, age, sex, diet, and environmental conditions. As a result, the clinical manifestations of crotalid envenomation can be highly variable, ranging from mild local reactions to severe systemic effects that may require intensive medical treatment and supportive care.

Crotalid venoms have been the subject of extensive research in recent years due to their potential therapeutic applications. For example, certain components of crotalid venoms have shown promise as drugs for treating various medical conditions, such as cardiovascular diseases, pain, and inflammation. However, further studies are needed to fully understand the mechanisms of action of these venom components and to develop safe and effective therapies based on them.

Carbodiimides are a class of chemical compounds with the general formula R-N=C=N-R, where R can be an organic group. They are widely used in the synthesis of various chemical and biological products due to their ability to act as dehydrating agents, promoting the formation of amide bonds between carboxylic acids and amines.

In the context of medical research and biochemistry, carbodiimides are often used to modify proteins, peptides, and other biological molecules for various purposes, such as labeling, cross-linking, or functionalizing. For example, the carbodiimide cross-linker EDC (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide) is commonly used to create stable amide bonds between proteins and other molecules in a process known as "EDC coupling."

It's important to note that carbodiimides can be potentially toxic and should be handled with care. They can cause irritation to the skin, eyes, and respiratory tract, and prolonged exposure can lead to more serious health effects. Therefore, appropriate safety precautions should be taken when working with these compounds in a laboratory setting.

Protein binding, in the context of medical and biological sciences, refers to the interaction between a protein and another molecule (known as the ligand) that results in a stable complex. This process is often reversible and can be influenced by various factors such as pH, temperature, and concentration of the involved molecules.

In clinical chemistry, protein binding is particularly important when it comes to drugs, as many of them bind to proteins (especially albumin) in the bloodstream. The degree of protein binding can affect a drug's distribution, metabolism, and excretion, which in turn influence its therapeutic effectiveness and potential side effects.

Protein-bound drugs may be less available for interaction with their target tissues, as only the unbound or "free" fraction of the drug is active. Therefore, understanding protein binding can help optimize dosing regimens and minimize adverse reactions.

Paper chromatography is a type of chromatography technique that involves the separation and analysis of mixtures based on their components' ability to migrate differently upon capillary action on a paper medium. This simple and cost-effective method utilizes a paper, typically made of cellulose, as the stationary phase. The sample mixture is applied as a small spot near one end of the paper, and then the other end is dipped into a developing solvent or a mixture of solvents (mobile phase) in a shallow container.

As the mobile phase moves up the paper by capillary action, components within the sample mixture separate based on their partition coefficients between the stationary and mobile phases. The partition coefficient describes how much a component prefers to be in either the stationary or mobile phase. Components with higher partition coefficients in the mobile phase will move faster and further than those with lower partition coefficients.

Once separation is complete, the paper is dried and can be visualized under ultraviolet light or by using chemical reagents specific for the components of interest. The distance each component travels from the origin (point of application) and its corresponding solvent front position are measured, allowing for the calculation of Rf values (retardation factors). Rf is a dimensionless quantity calculated as the ratio of the distance traveled by the component to the distance traveled by the solvent front.

Rf = (distance traveled by component) / (distance traveled by solvent front)

Paper chromatography has been widely used in various applications, such as:

1. Identification and purity analysis of chemical compounds in pharmaceuticals, forensics, and research laboratories.
2. Separation and detection of amino acids, sugars, and other biomolecules in biological samples.
3. Educational purposes to demonstrate the principles of chromatography and separation techniques.

Despite its limitations, such as lower resolution compared to high-performance liquid chromatography (HPLC) and less compatibility with volatile or nonpolar compounds, paper chromatography remains a valuable tool for quick, qualitative analysis in various fields.

I'm sorry for any confusion, but "horses" is not a medical term. It is the common name given to the species *Equus ferus caballus*, which are large domesticated mammals used for transportation, work, and recreation. If you have any questions about horses or a related topic that you would like a medical perspective on, please let me know and I'd be happy to help!

Carboxypeptidase B is a type of enzyme that belongs to the peptidase family. It is also known as carboxypeptidase B1 or CpB. This enzyme plays a crucial role in the digestion of proteins by cleaving specific amino acids from the carboxyl-terminal end of polypeptides.

Carboxypeptidase B preferentially removes basic arginine and lysine residues from protein substrates, making it an essential enzyme in various physiological processes, including blood clotting, hormone processing, and neuropeptide metabolism. It is synthesized as an inactive zymogen, procarboxypeptidase B, which is converted to its active form upon proteolytic activation.

In addition to its physiological functions, carboxypeptidase B has applications in research and industry, such as protein sequencing, peptide synthesis, and food processing.

Cystine is a naturally occurring amino acid in the body, which is formed from the oxidation of two cysteine molecules. It is a non-essential amino acid, meaning that it can be produced by the body and does not need to be obtained through diet. Cystine plays important roles in various biological processes, including protein structure and antioxidant defense. However, when cystine accumulates in large amounts, it can form crystals or stones, leading to conditions such as cystinuria, a genetic disorder characterized by the formation of cystine kidney stones.

Neurospora is not a medical term, but a genus of fungi commonly found in the environment. It is often used in scientific research, particularly in the fields of genetics and molecular biology. The most common species used in research is Neurospora crassa, which has been studied extensively due to its haploid nature, simple genetic structure, and rapid growth rate. Research using Neurospora has contributed significantly to our understanding of fundamental biological processes such as gene regulation, metabolism, and circadian rhythms.

Molecular cloning is a laboratory technique used to create multiple copies of a specific DNA sequence. This process involves several steps:

1. Isolation: The first step in molecular cloning is to isolate the DNA sequence of interest from the rest of the genomic DNA. This can be done using various methods such as PCR (polymerase chain reaction), restriction enzymes, or hybridization.
2. Vector construction: Once the DNA sequence of interest has been isolated, it must be inserted into a vector, which is a small circular DNA molecule that can replicate independently in a host cell. Common vectors used in molecular cloning include plasmids and phages.
3. Transformation: The constructed vector is then introduced into a host cell, usually a bacterial or yeast cell, through a process called transformation. This can be done using various methods such as electroporation or chemical transformation.
4. Selection: After transformation, the host cells are grown in selective media that allow only those cells containing the vector to grow. This ensures that the DNA sequence of interest has been successfully cloned into the vector.
5. Amplification: Once the host cells have been selected, they can be grown in large quantities to amplify the number of copies of the cloned DNA sequence.

Molecular cloning is a powerful tool in molecular biology and has numerous applications, including the production of recombinant proteins, gene therapy, functional analysis of genes, and genetic engineering.

Chromatography, agarose is a type of chromatography technique that utilizes agarose gel as the stationary phase in the separation and analysis of biological molecules, such as DNA, RNA, and proteins. This method is commonly used in molecular biology for various applications, including DNA fragment separation, protein purification, and detection of specific nucleic acid sequences or proteins.

Agarose gel is a matrix made from agarose, a polysaccharide derived from seaweed. It has a porous structure with uniform pore size that allows for the size-based separation of molecules based on their ability to migrate through the gel under an electric field (in the case of electrophoresis) or by capillary action (in the case of capillary electrophoresis).

The charged molecules, such as DNA or proteins, interact with the agarose matrix and move through the gel at different rates depending on their size, charge, and shape. Smaller molecules can migrate more quickly through the pores of the gel, while larger molecules are retarded due to their inability to easily pass through the pores. This results in a separation of the molecules based on their physical properties, allowing for their analysis and characterization.

In summary, chromatography, agarose refers to the use of agarose gel as the stationary phase in the separation and analysis of biological molecules using various chromatography techniques, such as electrophoresis or capillary electrophoresis.

Mass spectrometry (MS) is an analytical technique used to identify and quantify the chemical components of a mixture or compound. It works by ionizing the sample, generating charged molecules or fragments, and then measuring their mass-to-charge ratio in a vacuum. The resulting mass spectrum provides information about the molecular weight and structure of the analytes, allowing for identification and characterization.

In simpler terms, mass spectrometry is a method used to determine what chemicals are present in a sample and in what quantities, by converting the chemicals into ions, measuring their masses, and generating a spectrum that shows the relative abundances of each ion type.

Troponin is a protein complex found in cardiac and skeletal muscle cells that plays a critical role in muscle contraction. It consists of three subunits: troponin C, which binds calcium ions; troponin I, which inhibits the interaction between actin and myosin in the absence of calcium; and troponin T, which binds to tropomyosin and helps anchor the complex to the muscle filament.

In clinical medicine, "troponin" usually refers to cardiac-specific isoforms of these proteins (cTnI and cTnT) that are released into the bloodstream following damage to the heart muscle, such as occurs in myocardial infarction (heart attack). Measurement of troponin levels in the blood is a sensitive and specific biomarker for the diagnosis of acute myocardial infarction.

A Structure-Activity Relationship (SAR) in the context of medicinal chemistry and pharmacology refers to the relationship between the chemical structure of a drug or molecule and its biological activity or effect on a target protein, cell, or organism. SAR studies aim to identify patterns and correlations between structural features of a compound and its ability to interact with a specific biological target, leading to a desired therapeutic response or undesired side effects.

By analyzing the SAR, researchers can optimize the chemical structure of lead compounds to enhance their potency, selectivity, safety, and pharmacokinetic properties, ultimately guiding the design and development of novel drugs with improved efficacy and reduced toxicity.

Lysine is an essential amino acid, which means that it cannot be synthesized by the human body and must be obtained through the diet. Its chemical formula is (2S)-2,6-diaminohexanoic acid. Lysine is necessary for the growth and maintenance of tissues in the body, and it plays a crucial role in the production of enzymes, hormones, and antibodies. It is also essential for the absorption of calcium and the formation of collagen, which is an important component of bones and connective tissue. Foods that are good sources of lysine include meat, poultry, fish, eggs, and dairy products.

"Swine" is a common term used to refer to even-toed ungulates of the family Suidae, including domestic pigs and wild boars. However, in a medical context, "swine" often appears in the phrase "swine flu," which is a strain of influenza virus that typically infects pigs but can also cause illness in humans. The 2009 H1N1 pandemic was caused by a new strain of swine-origin influenza A virus, which was commonly referred to as "swine flu." It's important to note that this virus is not transmitted through eating cooked pork products; it spreads from person to person, mainly through respiratory droplets produced when an infected person coughs or sneezes.

"Chickens" is a common term used to refer to the domesticated bird, Gallus gallus domesticus, which is widely raised for its eggs and meat. However, in medical terms, "chickens" is not a standard term with a specific definition. If you have any specific medical concern or question related to chickens, such as food safety or allergies, please provide more details so I can give a more accurate answer.

... can be stored under dry conditions at 2 to 8 °C for extended periods. Cyanogen bromide is volatile, and ... "Cyanogen Bromide HSDB 708". HSDB. NIH / NLM. 2009-04-07. Lunn, G.; Sansone, E. B. (1985). "Destruction of Cyanogen Bromide and ... "Cyanogen Bromide MSDS Number: C6600". J. T. Baker. 1996-08-12. Teeri, A. E. (1948). "Thiamine and the Cyanogen Bromide Reaction ... Like some other cyanogen compounds, cyanogen bromide undergoes an exothermic trimerisation to cyanuric bromide ((BrCN)3). This ...
Cyanogen chloride and cyanogen bromide each trimerize at elevated temperatures over a carbon catalyst. The chloride gives ... Morris, Joel; Kovács, Lajos; Ohe, Kouichi (2015). "Cyanogen Bromide". Encyclopedia of Reagents for Organic Synthesis. pp. 1-8. ... Joel Morris; Lajos Kovács (2008). "Cyanogen Bromide". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X. ... Like the chloride, it undergoes ab exothermic trimerisation to form cyanuric bromide. This reaction is catalyzed by traces of ...
... and hence is used for compounds such as cyanogen bromide (NCBr) (but see also Cyano radical.) Cyanogen is the anhydride of ... ISBN 978-3-642-11271-3. Hartman, W. W.; Dreger, E. E. (1931). "Cyanogen Bromide" (PDF). Organic Syntheses. 11: 30.; Collective ... Cyanogen is commonly found in comets. In 1910 a spectroscopic analysis of Halley's Comet found cyanogen in the comet's tail, ... Media related to Cyanogen at Wikimedia Commons Chisholm, Hugh, ed. (1911). "Cyanogen" . Encyclopædia Britannica (11th ed.). ...
The von Braun reaction is an organic reaction in which a tertiary amine reacts with cyanogen bromide to an organocyanamide. An ... the trimethylamine reacts with the cyanogen bromide to form a quaternary ammonium salt, which in the next step reacts by ... "The Von Braun Cyanogen Bromide Reaction". Organic Reactions. 7 (4): 198-262. doi:10.1002/0471264180.or007.04. ISBN 0471264180. ... most chemist have replaced cyanogen bromide reagent with chloroethyl chloroformate reagent instead. It appears as though ...
Characterization of disulfide-containing cyanogen-bromide fragments". Eur. J. Biochem. 77 (3): 595-610. doi:10.1111/j.1432- ...
Cyanogen bromide peptides and complete amino acid sequence". J. Biol. Chem. 255 (13): 6412-20. doi:10.1016/S0021-9258(18)43754- ...
I. Amino acid sequence of the cyanogen bromide peptides". The Journal of Biological Chemistry. 255 (7): 2878-85. doi:10.1016/ ...
1-Naphthylamine is reacted with cyanogen bromide to give 2. Treatment of this intermediate with 3-ethyl-N-methylaniline leads ...
Cyanogen bromide cleavage and N-terminal sequences of the fragments". The Biochemical Journal. 215 (3): 565-71. doi:10.1042/ ...
It is formed by the spontaneous trimerisation of cyanogen bromide. Cyanuric bromide can be used to synthesize substituted ... Cyanuric bromide reacts with water, particularly in alkaline conditions to cyanuric acid and hydrogen bromide. Cyanuric bromide ... The trimerization reaction of cyanogen bromide (BrCN) is catalyzed by aluminium trichloride or hydrogen bromide. Smolin, Edwin ... Cyanuric bromide is a heterocyclic compound with formula C3N3Br3. It contains a six-membered ring of alternating nitrogen and ...
Cusumano CL, Taniuchi H, Anfinsen CB (1968). "Staphylococcal nuclease (Foggi strain). I. Order of cyanogen bromide fragments ...
For example, cyanogen bromide cleaves the peptide bond after a methionine. Similar methods may be used to specifically cleave ...
This is formed by a reaction between BPA and cyanogen bromide. Examples include BT-Epoxy, which is one of a number of resins ...
Examples of cleaving agents used are cyanogen bromide, pepsin, and trypsin. Muller, P. (1 January 1994). "Glossary of terms ...
Amino acid sequence of heavy-chain cyanogen bromide fragments H1-H4". Biochemistry. 9 (16): 3161-70. doi:10.1021/bi00818a008. ... 8. Amino acid sequence of heavy-chain cyanogen bromide fragments H5-H7". Biochemistry. 9 (16): 3171-81. doi:10.1021/bi00818a009 ... the cyanogenbromide cleavage products, and the disulfide bridges (author's transl)]". Hoppe-Seyler's Z. Physiol. Chem. 357 (11 ...
Isolation of cyanogen bromide peptides: complete covalent structure of the polypeptide chain". The Journal of Biological ...
... cyanogen bromide fragment of human thyroglobulin". Archives of Biochemistry and Biophysics. 320 (1): 96-105. doi:10.1006/abbi. ...
Cyanogen fluoride Cyanogen chloride Cyanogen bromide Cyanogen iodide C.R. Noller (2013), Lehrbuch der Organischen Chemie (in ... in particular cyanogen chloride and cyanogen bromide, are important starting materials for the incorporation of the cyanogen ... It has been suggested that cyanogen chloride be used by the military as poison gas. Cyanogen bromide is a solid that is ... A cyanogen halide is a molecule consisting of cyanide and a halogen. Cyanogen halides are chemically classified as ...
The racemic synthesis involves addition/cyclization reaction of 2-amino-1-phenylethanol with cyanogen bromide. A similar ...
Treatment of that with cyanogen bromide under von Braun reaction conditions leads to the isolable aminocyanide. This is the ...
Smith M, Ratledge C, Crook S (1990). "Properties of cyanogen bromide-activated, Agarose-immobilized catechol 1,2-dioxygenase ...
Homoserine lactone is also a product of the proteolytic reaction of cyanogen bromide (CNBr) with a methionine residue. This ...
Cacodyl Cyanogen bromide Dimethyl(trifluoromethylthio)arsine Diphenylcyanoarsine Mercury(II) cyanide Mercury oxycyanide ...
Modifications have shown that it is possible to use sodium cyanide or cyanogen bromide in place of hydrogen cyanide. The ...
Digestion is done either by endopeptidases such as trypsin or pepsin or by chemical reagents such as cyanogen bromide. ...
Green PR, Vanaman TC, Modrich P, Bell RM (1983). "Partial NH2- and COOH-terminal sequence and cyanogen bromide peptide analysis ...
... , or its lactone form, is the product of a cyanogen bromide cleavage of a peptide by degradation of methionine. ...
Lux SE, John KM, Ronan R, Brewer HB (Dec 1972). "Isolation and characterization of the tryptic and cyanogen bromide peptides of ...
Seyer JM, Kang AH (1989). "Covalent structure of collagen: amino acid sequence of three cyanogen bromide-derived peptides from ...
The cyanogen bromide, by comparison, transformed norephedrine into the cis isomer and norpseudoephedrine into the trans isomers ... The cyanate reaction proceeds differently from the cyanogen bromide and transforms norephedrine into trans-4-methylaminorex ... such as replacing cyanogen bromide with sodium or potassium cyanate to form an intermediate and then reacting it with ... generally synthesized from dl-phenylpropanolamine in one step by cyclization with cyanogen bromide (sometimes prepared in situ ...
Cyanogen bromide can be stored under dry conditions at 2 to 8 °C for extended periods. Cyanogen bromide is volatile, and ... "Cyanogen Bromide HSDB 708". HSDB. NIH / NLM. 2009-04-07. Lunn, G.; Sansone, E. B. (1985). "Destruction of Cyanogen Bromide and ... "Cyanogen Bromide MSDS Number: C6600". J. T. Baker. 1996-08-12. Teeri, A. E. (1948). "Thiamine and the Cyanogen Bromide Reaction ... Like some other cyanogen compounds, cyanogen bromide undergoes an exothermic trimerisation to cyanuric bromide ((BrCN)3). This ...
Cyanogen bromide anion. [BrCN]- (g). 57.9. 54.2. ± 3.8. kJ/mol. 105.9220 ±. 0.0013. 54092-05-6*0. ... Cyanogen bromide cation. [BrCN]+ (g). 1331.3. 1325.0. ± 1.1. kJ/mol. 105.9209 ±. 0.0013. 34749-77-4*0. ... Cyanogen bromide. BrCN (g). 186.7. 180.2. ± 1.1. kJ/mol. 105.9214 ±. 0.0013. 506-68-3*0. ... Isocyanogen bromide anion. [BrNC]- (g). 105.0. 101.8. ± 4.6. kJ/mol. 105.9220 ±. 0.0013. *238754-53-5*0. ...
Isolation and characterization of tryptic, cyanogen bromide, and maleylated tryptic peptides. H. J. Evans, H. M. Steinman, R. L ... Isolation and characterization of tryptic, cyanogen bromide, and maleylated tryptic peptides. Together they form a unique ...
Alfa-amylase showed optimal activity at pH 6.0 Cyanogen bromide was prepared and was used to activate sephadex G200 at pH 11.5 ... The volume of the cyanogen bromide activated gel, at this pH decreased by about 50 percent, compared to that of the unactivated ... Alfa-amylase was coupled to cyanogen bromide activated Sephadex G200 at pH8.3 and 7.0. Coupling of the enzyme led to further ... Alfa-amylase showed optimal activity at pH 6.0 Cyanogen bromide was prepared and was used to activate sephadex G200 at pH 11.5 ...
Cyanogen bromide. Diethyl sulfide. Hydrocyanic acid. Iodine pentafluoride. Kendalite. Magnesium arsenide. Martonite. ... Cyanogen chloride. Diisopropyl methylphosphonate. Dimethyldisulfide. Dimethyl methylphosphonate. Diphenylchlorarsine. ...
Reaction products of 4,4-(1,3-phenylene-bis(1-methylethylidene))bis-phenol and cyanogen bromide. ...
Reaction products of 4,4-(1,3-phenylene-bis(1-methylethylidene))bis-phenol and cyanogen bromide. ...
Cyanogen Bromide. Definition. Met identification, Cleaves at C-end. Supporting users have an ad free experience! ...
Exposure to cyanogen chloride (CK) can be rapidly fatal. ... Cyanogen chloride (CK) is a highly volatile and toxic chemical ... Xie YF, Reckhow Da [1993]. A rapid and simple analytical method for cyanogen chloride and cyanogen-bromide in drinking-water. ... Cancho B, Ventura F, Galceran MT [2000]. Simultaneous determination of cyanogen chloride and cyanogen bromide in treated water ... Water: Cyanogen chloride (CK) can be used to contaminate water.. *Food: Cyanogen chloride (CK) can be used to contaminate food. ...
Keywords: Sodium Dodecyl Sulfate; Mixture Component; Gene Chip; Cyanogen Bromide; Mixture Element ...
Cyanogen bromide (Geo). CNBr 4125 Cyanogen bromide. CNBr 4126 3-Bromo-3-methyldiazirine. C2H3N2Br ...
Interaction of the cyanogen bromide fragments from apolipoprotein glutamine II (A-II) with phosphatidylcholine. J Biol Chem. ... Isolation and characterization of the tryptic and cyanogen bromide peptides of apoLp-Gln-II (apoA-II), plasma high density ... Identification of the lipid-binding cyanogen bromide fragment from the cystine-containing high density apolipoprotein, APOLP- ...
Preparation of cyanogen bromide and a polymethine dye. I think it might be possible to circumvent the cyanogen bromide by ...
Our coupling method provides several advantages over the traditional cyanogen bromide procedure:. *Maximum carbohydrate binding ...
Treatment with cyanogen bromide gives three peptides with the following amino acid compositions: 1. His, Lys, Met, Pro, Ser 2. ... Treatment with cyanogen bromide gives three peptides with the following amino acid compositions: 1. His, Lys, Met, Pro, Ser 2. ...
ATDGTVJJHBUTRL-UHFFFAOYSA-N Cyanogen bromide Chemical compound BrC#N ATDGTVJJHBUTRL-UHFFFAOYSA-N 0.000 description 4 ... such as cyanogen bromide (CNBr) cleavage (discussed in U.S. Pat. No. 4,960,868 and elsewhere). However such chemical cleavage ...
To determine the disulfide bond arrangement of the eight cysteines of gC1(457t),the protein was cleaved with cyanogen bromide. ... Further proteolysis of the cyanogen bromide-generated fragment containing cysteine 5 through cysteine 8, combined with mass ...
Cyanogen Bromide. MESH. Halobacterium/metabolism. MESH. Membrane Proteins/biosynthesis. MESH. Molecular Weight. MESH. ...
DOI: 10.1055/s-0036-1588533) cyanogen bromide to convert the allyl amine 17 to the cyanamide 18. C. Oliver Kappe of the ... DOI: 10.1002/anie.201708533 ) a flow system for the in situ generation and use of the very reactive cyanogen bromide. Michel R ...
... and dander coupled to cyanogen bromide-activated cellulose beads. A sample was considered positive if the binding to the ... Cyanogen; Bromides; Cellulose; Albumin; Statistical analysis; Questionnaires; Respiratory diseases; Respiratory system ...
Bell, J., Duhon, S., and Doctor, V. M. The effect of fucoidan, heparin and cyanogen bromide-fibrinogen on the activation of ...
Concanavalin A (Con A) Agarose consists of Con A coupled to agarose by the cyanogen bromide method. Con A is a tetrameric ...
These include, but are not limited to, cyanogen chloride and cyanogen bromide (gases with potent pulmonary irritant effects), ... Cyanogen chloride (CNCl or CK) is heavier and will sink to low-lying areas and increase the risk of exposure. [6] ... Cyanogen chloride is used in mining and metalworking, and thus may be involved in an industrial accident. By nature of its ... The introduction of cyanogen chloride by the French in 1916 made available a compound that, being both more toxic and less ...
... of the intact protein and N-terminal sequencing of peptide fragments obtained from endopeptidase and cyanogen bromide ...
... supernatants were precleared with cyanogen bromide-activated and Tris-blocked (control) sepharose beads (GE Healthcare, ...
... cyanogen bromide under the influence of UVR and the production of a pink colour by coupling the cyanogen bromide with benzidine ... 14C-vinyl bromide. Toxicol. appl. Pharmacol., 44 : 481-489. BOND, E.J. & BUCKLAND, C.T. (1976) Control of insects with ... fumigants at low temperatures: toxicity of mixtures of methyl bromide and acrylonitrile to three species of insects. J. econ. ...
For the final step, several affinity gels were tested and the 1 containing cycloserine coupled to CNBr [cyanogen bromide]- ...
... and its cyanogen bromide cleaved fragments examined by monoclonal antibodies and Western blotting. Arch Virol. 96:97-107, 1987 ...
Order of cyanogen bromide fragments in the polypeptide chain of human plasma albumin. Partial amino-acid sequence of the ... Amino acid sequence of cyanogen bromide fragment CB3(Cys) of human serum albumin. 1977, Vol. 42, Issue 4, pp. 1248-1261 [ ... Amino acid sequence of cyanogen bromide fragment CB6(Pro) of human plasma albumin. 1975, Vol. 40, Issue 12, pp. 3942-3952 [ ... Amino-acid sequence of cyanogen bromide fragment CB5(Phe) of human plasma albumin. 1975, Vol. 40, Issue 12, pp. 3932-3941 [ ...
  • Alfa-amylase was coupled to cyanogen bromide activated Sephadex G200 at pH8.3 and 7.0. (
  • The serum samples were analyzed for total IgE content by a commercial radioimmunoassay (PRIST), and for specific IgE antibodies by the radioallergosorbent test (RAST) using extracts of swine urine, serum, blood, and dander coupled to cyanogen bromide-activated cellulose beads. (
  • Cyanogen chloride (CK) is a highly volatile and toxic chemical asphyxiant that interferes with the body's ability to use oxygen. (
  • Exposure to cyanogen chloride (CK) can be rapidly fatal. (
  • Cyanogen chloride (CK) has strong irritant and choking effects. (
  • Cyanogen chloride (CK) is a chemical warfare agent (military designation CK). (
  • Indoor Air: Cyanogen chloride (CK) can be released into indoor air as a liquid spray (aerosol) or as a gas. (
  • Water: Cyanogen chloride (CK) can be used to contaminate water. (
  • Agricultural: If cyanogen chloride (CK) is released into the air as a liquid spray (aerosol), it has the potential to contaminate agricultural products. (
  • If cyanogen chloride (CK) is released as a gas, it is highly unlikely to contaminate agricultural products. (
  • Cyanogen chloride (CK) can affect the body by inhalation, ingestion, skin contact, or eye contact. (
  • Cyanogen chloride (CNCl or CK) is heavier and will sink to low-lying areas and increase the risk of exposure. (
  • the other is cyanogen chloride (NATO designation CK). (
  • The introduction of cyanogen chloride by the French in 1916 made available a compound that, being both more toxic and less volatile, was a more effective chemical agent. (
  • Plate XXVII (Fig. 1): Lungs of dog, surviving 5 hours, gassed with a high concentration of cyanogen chloride. (
  • Cyanogen (chloride and bromide) poisoning. (
  • DBPs are formed by the reaction of natural organic matter (NOM) or inorganic substances in water (e.g. chloride, bromide) with the disinfectant chemical. (
  • Cyanogen bromide is the inorganic compound with the formula (CN)Br or BrCN. (
  • Like some other cyanogen compounds, cyanogen bromide undergoes an exothermic trimerisation to cyanuric bromide ((BrCN)3). (
  • The varied speciality and pharmaceutical companies that we deal in consists of Cyanogen Bromide Cyclopropyl Isothiocyanate, Malonate Derivatives, Methyl 4-Chlorobutyrate, Thiophosgene and many more. (
  • Methyl bromide poisoning primarily occurs after inhalational exposure, but concurrent dermal exposure might also occur. (
  • Methyl bromide is an ocular, dermal, and mucous membrane irritant. (
  • Detection of bromide below toxic levels does not rule out methyl bromide poisoning. (
  • Detection of methyl bromide in environmental samples, as determined by NIOSH. (
  • A clinically compatible case in which a high index of suspicion (credible threat or patient history regarding location and time) exists for methyl bromide exposure, or an epidemiologic link exists between this case and a laboratory-confirmed case. (
  • Health effects associated with sulfuryl fluoride and methyl bromide exposure among structural fumigation workers. (
  • Methyl bromide intoxication during grain store fumigation. (
  • Death and injury caused by methyl bromide-an insecticide fumigant. (
  • Treatment with cyanogen bromide gives three peptides with the following amino acid compositions: 1. (
  • Cyanogen bromide peptides and complete amino acid sequence. (
  • This has been achieved by the sequence analysis of peptides derived by enzymatic digestion with trypsin, lysylendopeptidase, and chymotrypsin, as well as by chemical cleavage with cyanogen bromide. (
  • Comparison of the amino acid sequences of cyanogen bromide cleaved isomerase with the known sequence of the peroxisomal bifunctional protein from the rat identified them as the same molecule. (
  • For the final step, several affinity gels were tested and the 1 containing cycloserine coupled to CNBr [cyanogen bromide]-activated Sepharose-4B was selected. (
  • HCN + HOBr}}} The main uses of cyanogen bromide are to immobilize proteins, fragment proteins by cleaving peptide bonds, and synthesize cyanamides and other molecules. (
  • Further proteolysis of the cyanogen bromide-generated fragment containing cysteine 5 through cysteine 8, combined with mass spectrometry and Edman degradation, showed that disulfide bonds link cysteine 5 (aa 386) to cysteine 8 (aa 442) and cysteine 6 (aa 390) to cysteine 7 (aa 419). (
  • If the sulfur in cysteine attacked cyanogen bromide, the bromide ion would deprotonate the cyanide adduct, leaving the sulfur uncharged and the beta carbon of the cysteine not electrophilic. (
  • In addition, a number of cyanide-containing compounds, known as cyanogens, may release cyanide during metabolism. (
  • dead link] Cyanogen bromide hydrolyzes peptide bonds at the C-terminus of methionine residues. (
  • Cyanogen bromide is often used to immobilize proteins by coupling them to reagents such as agarose for affinity chromatography. (
  • Cyanogen bromide is also often used because it reacts with the hydroxyl groups on agarose to form cyanate esters and imidocarbonates. (
  • Also, cyanogen bromide activation involves the attachment of a ligand to agarose by an isourea bond, which is positively charged at neutral pH and thus unstable. (
  • Because of its simplicity and mild pH conditions, cyanogen bromide activation is the most common method for preparing affinity gels. (
  • This vaccine was prepared from the C. parvum oocysts antigen using immune affinity chromatography with cyanogen bromide-activated Sepharose-4B beads. (
  • Order of cyanogen bromide fragments in the polypeptide chain of human plasma albumin. (
  • To determine the disulfide bond arrangement of the eight cysteines of gC1(457t),the protein was cleaved with cyanogen bromide. (
  • The carbon atom in cyanogen bromide is bonded to bromine by a single bond and to nitrogen by a triple bond (i.e. (
  • The electron density in cyanogen bromide is shifted away from the carbon atom, making it unusually electrophilic, and towards the more electronegative bromine and nitrogen. (
  • however, detection of elevated bromide levels in serum (reference level: 50-100 mg/L) might indicate that an exposure has occurred. (
  • An immunoaffinity chromatography matrix was prepared by coupling antibody to cyanogen bromide-activated Sepharose. (
  • The disadvantages of this approach include the toxicity of cyanogen bromide and its sensitivity to oxidation. (
  • ATTYGALLE, AB, Studies on immobilization of alfa- amylase to cyanogen bromide activated sephadex g 200, University of Sri Lanka (Colombo Campus) UC(MED), 1977: 50p. (
  • The volume of the cyanogen bromide activated gel, at this pH decreased by about 50 percent, compared to that of the unactivated Sephadex G200. (
  • Sequence data were obtained by the manual and solid-phase sequencing of peptides derived from enzymatic digestions with trypsin, chymotrypsin, pepsin, and Staphylococcus aureus protease as well as by chemical cleavage with cyanogen bromide. (
  • The synthesis of norlysergamides (26-33) by reaction of lysergamides (4) (LSD) and (10-16) with cyanogen bromide to (18-15) and subsequent hydrolysis with HCl-dioxane is reported. (
  • Nor-LSD (26) was converted to its N6-allyl, -ethyl and -propyl - derivatives by reaction with allyl bromide, EtI or PrBr in the presence of NaH. (
  • [6] It is preferable over benzyl bromide for the preparation of this reagent, since the reaction of the bromide with magnesium tends to form the Wurtz coupling product 1,2-diphenylethane . (
  • If the sulfur in cysteine attacked cyanogen bromide, the bromide ion would deprotonate the cyanide adduct, leaving the sulfur uncharged and the beta carbon of the cysteine not electrophilic. (
  • Isolation and alignment of the five cyanogen bromide fragments and the amino acid sequences of four of the fragments. (
  • Cyanogen bromide digestion of the nuclease yielded five fragments, designated A, B, C, D, and E. These fragments have been purified and analyzed for amino acid composition. (
  • The chemical cyanogen bromide is commonly used to break polypeptides into smaller fragments. (
  • Brenner, Sydney, "Immunology Cyanalation and Cyanogen Bromide Digestion (6 of 8) ," CSHL Archives Repository , Reference SB/6/2/139, accessed December 10, 2023, (
  • Cyanogen bromide is often used to immobilize proteins by coupling them to reagents such as agarose for affinity chromatography. (
  • Proteins and other molecules containing primary amino groups were covalently bonded to the acrylic spheres under a variety of mild conditions by the aqueous carbodiimide, cyanogen bromide, and glutaraldehyde methods. (
  • The disadvantages of this approach include the toxicity of cyanogen bromide and its sensitivity to oxidation. (
  • Cyanogen bromide is indicated as well, but with a different sensitivity. (
  • Chemical cleavage with hydroxylamine and cyanogen bromide also revealed a similar pattern for liganded and unliganded AhR. (
  • Because of its simplicity and mild pH conditions, cyanogen bromide activation is the most common method for preparing affinity gels. (
  • Trichloroacetonitrile is used as the cyano source to synthesize N-nitrile instead of highly toxic and expensive cyanogen bromide. (
  • Labeling was effected with cyanogen bromide activation and aminoalkylation for specific detection of endogeneous sugar receptors, especially lectins. (
  • The serum samples were analyzed for total IgE content by a commercial radioimmunoassay (PRIST), and for specific IgE antibodies by the radioallergosorbent test (RAST) using extracts of swine urine, serum, blood, and dander coupled to cyanogen bromide-activated cellulose beads. (
  • The carbon atom in cyanogen bromide is bonded to bromine by a single bond and to nitrogen by a triple bond (i.e. (
  • These interactions are inhibited by denatured, single collagen chains or a subset of their cyanogen bromide peptides in a dose-dependent manner. (