Tandem Mass Spectrometry: A mass spectrometry technique using two (MS/MS) or more mass analyzers. With two in tandem, the precursor ions are mass-selected by a first mass analyzer, and focused into a collision region where they are then fragmented into product ions which are then characterized by a second mass analyzer. A variety of techniques are used to separate the compounds, ionize them, and introduce them to the first mass analyzer. For example, for in GC-MS/MS, GAS CHROMATOGRAPHY-MASS SPECTROMETRY is involved in separating relatively small compounds by GAS CHROMATOGRAPHY prior to injecting them into an ionization chamber for the mass selection.Mass Spectrometry: An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.Spectrometry, Mass, Electrospray Ionization: A mass spectrometry technique used for analysis of nonvolatile compounds such as proteins and macromolecules. The technique involves preparing electrically charged droplets from analyte molecules dissolved in solvent. The electrically charged droplets enter a vacuum chamber where the solvent is evaporated. Evaporation of solvent reduces the droplet size, thereby increasing the coulombic repulsion within the droplet. As the charged droplets get smaller, the excess charge within them causes them to disintegrate and release analyte molecules. The volatilized analyte molecules are then analyzed by mass spectrometry.Chromatography, Liquid: Chromatographic techniques in which the mobile phase is a liquid.Peptides: 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.Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization: A mass spectrometric technique that is used for the analysis of large biomolecules. Analyte molecules are embedded in an excess matrix of small organic molecules that show a high resonant absorption at the laser wavelength used. The matrix absorbs the laser energy, thus inducing a soft disintegration of the sample-matrix mixture into free (gas phase) matrix and analyte molecules and molecular ions. In general, only molecular ions of the analyte molecules are produced, and almost no fragmentation occurs. This makes the method well suited for molecular weight determinations and mixture analysis.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Proteomics: The systematic study of the complete complement of proteins (PROTEOME) of organisms.Gas Chromatography-Mass Spectrometry: A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.Proteome: The protein complement of an organism coded for by its genome.Amino Acid Sequence: 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.Molecular Sequence Data: 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.Peptide Fragments: Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.Peptide Mapping: 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.Spectrometry, Mass, Fast Atom Bombardment: A mass spectrometric technique that is used for the analysis of a wide range of biomolecules, such as glycoalkaloids, glycoproteins, polysaccharides, and peptides. Positive and negative fast atom bombardment spectra are recorded on a mass spectrometer fitted with an atom gun with xenon as the customary beam. The mass spectra obtained contain molecular weight recognition as well as sequence information.Electrophoresis, Gel, Two-Dimensional: Electrophoresis in which a second perpendicular electrophoretic transport is performed on the separate components resulting from the first electrophoresis. This technique is usually performed on polyacrylamide gels.Solid Phase Extraction: An extraction method that separates analytes using a solid phase and a liquid phase. It is used for preparative sample cleanup before analysis by CHROMATOGRAPHY and other analytical methods.Neonatal Screening: The identification of selected parameters in newborn infants by various tests, examinations, or other procedures. Screening may be performed by clinical or laboratory measures. A screening test is designed to sort out healthy neonates (INFANT, NEWBORN) from those not well, but the screening test is not intended as a diagnostic device, rather instead as epidemiologic.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.Reproducibility of Results: The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.Spectrometry, Mass, Secondary Ion: A mass-spectrometric technique that is used for microscopic chemical analysis. A beam of primary ions with an energy of 5-20 kiloelectronvolts (keV) bombards a small spot on the surface of the sample under ultra-high vacuum conditions. Positive and negative secondary ions sputtered from the surface are analyzed in a mass spectrometer in regards to their mass-to-charge ratio. Digital imaging can be generated from the secondary ion beams and their intensity can be measured. Ionic images can be correlated with images from light or other microscopy providing useful tools in the study of molecular and drug actions.Reference Standards: A basis of value established for the measure of quantity, weight, extent or quality, e.g. weight standards, standard solutions, methods, techniques, and procedures used in diagnosis and therapy.Tandem Repeat Sequences: Copies of DNA sequences which lie adjacent to each other in the same orientation (direct tandem repeats) or in the opposite direction to each other (INVERTED TANDEM REPEATS).Calibration: Determination, by measurement or comparison with a standard, of the correct value of each scale reading on a meter or other measuring instrument; or determination of the settings of a control device that correspond to particular values of voltage, current, frequency or other output.Isotope Labeling: Techniques for labeling a substance with a stable or radioactive isotope. It is not used for articles involving labeled substances unless the methods of labeling are substantively discussed. Tracers that may be labeled include chemical substances, cells, or microorganisms.Ions: An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)Limit of Detection: Concentration or quantity that is derived from the smallest measure that can be detected with reasonable certainty for a given analytical procedure.Metabolism, Inborn Errors: Errors in metabolic processes resulting from inborn genetic mutations that are inherited or acquired in utero.Sequence Analysis, Protein: A process that includes the determination of AMINO ACID SEQUENCE of a protein (or peptide, oligopeptide or peptide fragment) and the information analysis of the sequence.Proteins: Linear POLYPEPTIDES that are synthesized on RIBOSOMES and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of AMINO ACIDS determines the shape the polypeptide will take, during PROTEIN FOLDING, and the function of the protein.Toxascariasis: Infections with nematodes of the genus TOXASCARIS.DEFICIENS Protein: DEFICIENS is a homeotic gene involved in the genetic control of Antirrhinum majus flower development. Its protein is one of the four founder proteins that structurally define the superfamily of MADS DOMAIN PROTEINS.Protein Binding: 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.Indicators and Reagents: Substances used for the detection, identification, analysis, etc. of chemical, biological, or pathologic processes or conditions. Indicators are substances that change in physical appearance, e.g., color, at or approaching the endpoint of a chemical titration, e.g., on the passage between acidity and alkalinity. Reagents are substances used for the detection or determination of another substance by chemical or microscopical means, especially analysis. Types of reagents are precipitants, solvents, oxidizers, reducers, fluxes, and colorimetric reagents. (From Grant & Hackh's Chemical Dictionary, 5th ed, p301, p499)Databases, Protein: Databases containing information about PROTEINS such as AMINO ACID SEQUENCE; PROTEIN CONFORMATION; and other properties.Hematuria: Presence of blood in the urine.Complex Mixtures: Mixtures of many components in inexact proportions, usually natural, such as PLANT EXTRACTS; VENOMS; and MANURE. These are distinguished from DRUG COMBINATIONS which have only a few components in definite proportions.Peptides, Cyclic: Peptides whose amino and carboxy ends are linked together with a peptide bond forming a circular chain. Some of them are ANTI-INFECTIVE AGENTS. Some of them are biosynthesized non-ribosomally (PEPTIDE BIOSYNTHESIS, NON-RIBOSOMAL).Deuterium: Deuterium. The stable isotope of hydrogen. It has one neutron and one proton in the nucleus.Chemical Fractionation: Separation of a mixture in successive stages, each stage removing from the mixture some proportion of one of the substances, for example by differential solubility in water-solvent mixtures. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Deuterium Exchange Measurement: A research technique to measure solvent exposed regions of molecules that is used to provide insight about PROTEIN CONFORMATION.Indicator Dilution Techniques: Methods for assessing flow through a system by injection of a known quantity of an indicator, such as a dye, radionuclide, or chilled liquid, into the system and monitoring its concentration over time at a specific point in the system. (From Dorland, 28th ed)Isomerism: The phenomenon whereby certain chemical compounds have structures that are different although the compounds possess the same elemental composition. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Chromatography, Reverse-Phase: A chromatography technique in which the stationary phase is composed of a non-polar substance with a polar mobile phase, in contrast to normal-phase chromatography in which the stationary phase is a polar substance with a non-polar mobile phase.Magnetic Resonance Spectroscopy: Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Substance Abuse Detection: Detection of drugs that have been abused, overused, or misused, including legal and illegal drugs. Urine screening is the usual method of detection.Antimicrobial Cationic Peptides: Small cationic peptides that are an important component, in most species, of early innate and induced defenses against invading microbes. In animals they are found on mucosal surfaces, within phagocytic granules, and on the surface of the body. They are also found in insects and plants. Among others, this group includes the DEFENSINS, protegrins, tachyplesins, and thionins. They displace DIVALENT CATIONS from phosphate groups of MEMBRANE LIPIDS leading to disruption of the membrane.Carbohydrate Sequence: The sequence of carbohydrates within POLYSACCHARIDES; GLYCOPROTEINS; and GLYCOLIPIDS.Oligopeptides: Peptides composed of between two and twelve amino acids.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Cattle: 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.Isotopes: Atomic species differing in mass number but having the same atomic number. (Grant & Hackh's Chemical Dictionary, 5th ed)Dried Blood Spot Testing: Techniques for using whole blood samples collected on filter paper for a variety of clinical laboratory tests.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Biotransformation: The chemical alteration of an exogenous substance by or in a biological system. The alteration may inactivate the compound or it may result in the production of an active metabolite of an inactive parent compound. The alterations may be divided into METABOLIC DETOXICATION, PHASE I and METABOLIC DETOXICATION, PHASE II.Fourier Analysis: Analysis based on the mathematical function first formulated by Jean-Baptiste-Joseph Fourier in 1807. The function, known as the Fourier transform, describes the sinusoidal pattern of any fluctuating pattern in the physical world in terms of its amplitude and its phase. It has broad applications in biomedicine, e.g., analysis of the x-ray crystallography data pivotal in identifying the double helical nature of DNA and in analysis of other molecules, including viruses, and the modified back-projection algorithm universally used in computerized tomography imaging, etc. (From Segen, The Dictionary of Modern Medicine, 1992)Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Software: Sequential operating programs and data which instruct the functioning of a digital computer.PhosphopeptidesOxygen Isotopes: Stable oxygen atoms that have the same atomic number as the element oxygen, but differ in atomic weight. O-17 and 18 are stable oxygen isotopes.Atmospheric Pressure: The pressure at any point in an atmosphere due solely to the weight of the atmospheric gases above the point concerned.Acetonitriles: Compounds in which a methyl group is attached to the cyano moiety.Metabolomics: The systematic identification and quantitation of all the metabolic products of a cell, tissue, organ, or organism under varying conditions. The METABOLOME of a cell or organism is a dynamic collection of metabolites which represent its net response to current conditions.Glycosylation: The chemical or biochemical addition of carbohydrate or glycosyl groups to other chemicals, especially peptides or proteins. Glycosyl transferases are used in this biochemical reaction.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Glucuronides: Glycosides of GLUCURONIC ACID formed by the reaction of URIDINE DIPHOSPHATE GLUCURONIC ACID with certain endogenous and exogenous substances. Their formation is important for the detoxification of drugs, steroid excretion and BILIRUBIN metabolism to a more water-soluble compound that can be eliminated in the URINE and BILE.Microchemistry: The development and use of techniques and equipment to study or perform chemical reactions, with small quantities of materials, frequently less than a milligram or a milliliter.Gases: The vapor state of matter; nonelastic fluids in which the molecules are in free movement and their mean positions far apart. Gases tend to expand indefinitely, to diffuse and mix readily with other gases, to have definite relations of volume, temperature, and pressure, and to condense or liquefy at low temperatures or under sufficient pressure. (Grant & Hackh's Chemical Dictionary, 5th ed)Molecular Weight: The sum of the weight of all the atoms in a molecule.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).Blood Specimen Collection: The taking of a blood sample to determine its character as a whole, to identify levels of its component cells, chemicals, gases, or other constituents, to perform pathological examination, etc.Drug Stability: The chemical and physical integrity of a pharmaceutical product.Oligosaccharides: Carbohydrates consisting of between two (DISACCHARIDES) and ten MONOSACCHARIDES connected by either an alpha- or beta-glycosidic link. They are found throughout nature in both the free and bound form.Analytic Sample Preparation Methods: Use of various chemical separation and extraction methods, such as SOLID PHASE EXTRACTION; CHROMATOGRAPHY; and SUPERCRITICAL FLUID EXTRACTION; to prepare samples for analytical measurement of components.Protein Conformation: 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).Amino Acids: 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.Aconitum: A plant genus of the family RANUNCULACEAE. Members contain a number of diterpenoid alkaloids including: aconitans, hypaconitine, ACONITINE, jesaconitine, ignavine, napelline, and mesaconitine. The common name of Wolfbane is similar to the common name for ARNICA.Models, Chemical: Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Protein Structure, Tertiary: The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.Carnitine: A constituent of STRIATED MUSCLE and LIVER. It is an amino acid derivative and an essential cofactor for fatty acid metabolism.Bacterial Proteins: Proteins found in any species of bacterium.Biological Markers: Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.Electrophoresis, Capillary: A highly-sensitive (in the picomolar range, which is 10,000-fold more sensitive than conventional electrophoresis) and efficient technique that allows separation of PROTEINS; NUCLEIC ACIDS; and CARBOHYDRATES. (Segen, Dictionary of Modern Medicine, 1992)Hydrolysis: The process of cleaving a chemical compound by the addition of a molecule of water.Cell Line: Established cell cultures that have the potential to propagate indefinitely.Kinetics: The rate dynamics in chemical or physical systems.PolysaccharidesGlycerophospholipids: Derivatives of phosphatidic acid in which the hydrophobic regions are composed of two fatty acids and a polar alcohol is joined to the C-3 position of glycerol through a phosphodiester bond. They are named according to their polar head groups, such as phosphatidylcholine and phosphatidylethanolamine.Lysine: An essential amino acid. It is often added to animal feed.Sequence Alignment: The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.PaperSpectroscopy, Fourier Transform Infrared: A spectroscopic technique in which a range of wavelengths is presented simultaneously with an interferometer and the spectrum is mathematically derived from the pattern thus obtained.Phosphorylation: The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.Carbohydrate Conformation: The characteristic 3-dimensional shape of a carbohydrate.Cysteine: A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.Immunoassay: A technique using antibodies for identifying or quantifying a substance. Usually the substance being studied serves as antigen both in antibody production and in measurement of antibody by the test substance.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Stereoisomerism: The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Nanotechnology: The development and use of techniques to study physical phenomena and construct structures in the nanoscale size range or smaller.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Escherichia coli: 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.Chromatography, Affinity: 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)DNA Adducts: The products of chemical reactions that result in the addition of extraneous chemical groups to DNA.Chromatography, Thin Layer: Chromatography on thin layers of adsorbents rather than in columns. The adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Drug Residues: Drugs and their metabolites which are found in the edible tissues and milk of animals after their medication with specific drugs. This term can also apply to drugs found in adipose tissue of humans after drug treatment.Cross-Linking Reagents: Reagents with two reactive groups, usually at opposite ends of the molecule, that are capable of reacting with and thereby forming bridges between side chains of amino acids in proteins; the locations of naturally reactive areas within proteins can thereby be identified; may also be used for other macromolecules, like glycoproteins, nucleic acids, or other.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.Glycopeptides: Proteins which contain carbohydrate groups attached covalently to the polypeptide chain. The protein moiety is the predominant group with the carbohydrate making up only a small percentage of the total weight.Cyclotrons: Devices for accelerating charged particles in a spiral path by a constant-frequency alternating electric field. This electric field is synchronized with the movement of the particles in a constant magnetic field.Chromatography, Gas: Fractionation of a vaporized sample as a consequence of partition between a mobile gaseous phase and a stationary phase held in a column. Two types are gas-solid chromatography, where the fixed phase is a solid, and gas-liquid, in which the stationary phase is a nonvolatile liquid supported on an inert solid matrix.Veterinary Drugs: Drugs used by veterinarians in the treatment of animal diseases. The veterinarian's pharmacological armamentarium is the counterpart of drugs treating human diseases, with dosage and administration adjusted to the size, weight, disease, and idiosyncrasies of the species. In the United States most drugs are subject to federal regulations with special reference to the safety of drugs and residues in edible animal products.Blotting, Western: Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.Blood Proteins: Proteins that are present in blood serum, including SERUM ALBUMIN; BLOOD COAGULATION FACTORS; and many other types of proteins.Protein Array Analysis: Ligand-binding assays that measure protein-protein, protein-small molecule, or protein-nucleic acid interactions using a very large set of capturing molecules, i.e., those attached separately on a solid support, to measure the presence or interaction of target molecules in the sample.Aldehydes: Organic compounds containing a carbonyl group in the form -CHO.Computational Biology: A field of biology concerned with the development of techniques for the collection and manipulation of biological data, and the use of such data to make biological discoveries or predictions. This field encompasses all computational methods and theories for solving biological problems including manipulation of models and datasets.Spectrophotometry, Ultraviolet: Determination of the spectra of ultraviolet absorption by specific molecules in gases or liquids, for example Cl2, SO2, NO2, CS2, ozone, mercury vapor, and various unsaturated compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Metabolome: The dynamic collection of metabolites which represent a cell's or organism's net metabolic response to current conditions.Cloning, Molecular: 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.Blood Chemical Analysis: An examination of chemicals in the blood.Australian Capital Territory: A territory of Australia consisting of Canberra, the national capital and surrounding land. It lies geographically within NEW SOUTH WALES and was established by law in 1988.Brain Chemistry: Changes in the amounts of various chemicals (neurotransmitters, receptors, enzymes, and other metabolites) specific to the area of the central nervous system contained within the head. These are monitored over time, during sensory stimulation, or under different disease states.Methylation: Addition of methyl groups. In histo-chemistry methylation is used to esterify carboxyl groups and remove sulfate groups by treating tissue sections with hot methanol in the presence of hydrochloric acid. (From Stedman, 25th ed)Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.EstersForensic Medicine: The application of medical knowledge to questions of law.Infant, Newborn: An infant during the first month after birth.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Microsomes, Liver: Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.Cell Line, Tumor: A cell line derived from cultured tumor cells.Glucuronates: Derivatives of GLUCURONIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that include the 6-carboxy glucose structure.Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Peptide Hydrolases: Hydrolases that specifically cleave the peptide bonds found in PROTEINS and PEPTIDES. Examples of sub-subclasses for this group include EXOPEPTIDASES and ENDOPEPTIDASES.Chromatography, Ion Exchange: 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.Structure-Activity Relationship: 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.Radioisotope Dilution Technique: Method for assessing flow through a system by injection of a known quantity of radionuclide into the system and monitoring its concentration over time at a specific point in the system. (From Dorland, 28th ed)Natriuretic Peptide, Brain: A PEPTIDE that is secreted by the BRAIN and the HEART ATRIA, stored mainly in cardiac ventricular MYOCARDIUM. It can cause NATRIURESIS; DIURESIS; VASODILATION; and inhibits secretion of RENIN and ALDOSTERONE. It improves heart function. It contains 32 AMINO ACIDS.Sequence Analysis: A multistage process that includes the determination of a sequence (protein, carbohydrate, etc.), its fragmentation and analysis, and the interpretation of the resulting sequence information.Electrons: Stable elementary particles having the smallest known negative charge, present in all elements; also called negatrons. Positively charged electrons are called positrons. The numbers, energies and arrangement of electrons around atomic nuclei determine the chemical identities of elements. Beams of electrons are called CATHODE RAYS.Carbon Isotopes: Stable carbon atoms that have the same atomic number as the element carbon, but differ in atomic weight. C-13 is a stable carbon isotope.DNA: A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).Plant Proteins: Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.Sphingolipids: A class of membrane lipids that have a polar head and two nonpolar tails. They are composed of one molecule of the long-chain amino alcohol sphingosine (4-sphingenine) or one of its derivatives, one molecule of a long-chain acid, a polar head alcohol and sometimes phosphoric acid in diester linkage at the polar head group. (Lehninger et al, Principles of Biochemistry, 2nd ed)Quality Control: A system for verifying and maintaining a desired level of quality in a product or process by careful planning, use of proper equipment, continued inspection, and corrective action as required. (Random House Unabridged Dictionary, 2d ed)Disulfides: Chemical groups containing the covalent disulfide bonds -S-S-. The sulfur atoms can be bound to inorganic or organic moieties.Plant Extracts: Concentrated pharmaceutical preparations of plants obtained by removing active constituents with a suitable solvent, which is evaporated away, and adjusting the residue to a prescribed standard.Alkanesulfonic Acids: Sulfonic acid derivatives that are substituted with an aliphatic hydrocarbon group.Alkylation: The covalent bonding of an alkyl group to an organic compound. It can occur by a simple addition reaction or by substitution of another functional group.Body Mass Index: An indicator of body density as determined by the relationship of BODY WEIGHT to BODY HEIGHT. BMI=weight (kg)/height squared (m2). BMI correlates with body fat (ADIPOSE TISSUE). Their relationship varies with age and gender. For adults, BMI falls into these categories: below 18.5 (underweight); 18.5-24.9 (normal); 25.0-29.9 (overweight); 30.0 and above (obese). (National Center for Health Statistics, Centers for Disease Control and Prevention)Protein Interaction Mapping: Methods for determining interaction between PROTEINS.Chemistry Techniques, Analytical: Methodologies used for the isolation, identification, detection, and quantitation of chemical substances.Protein Structure, Secondary: The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.Amino Acid Motifs: Commonly observed structural components of proteins formed by simple combinations of adjacent secondary structures. A commonly observed structure may be composed of a CONSERVED SEQUENCE which can be represented by a CONSENSUS SEQUENCE.Glycerylphosphorylcholine: A component of PHOSPHATIDYLCHOLINES or LECITHINS, in which the two hydroxy groups of GLYCEROL are esterified with fatty acids. (From Stedman, 26th ed) It counteracts the effects of urea on enzymes and other macromolecules.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Lipids: A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)Hydrogen: The first chemical element in the periodic table. It has the atomic symbol H, atomic number 1, and atomic weight [1.00784; 1.00811]. It exists, under normal conditions, as a colorless, odorless, tasteless, diatomic gas. Hydrogen ions are PROTONS. Besides the common H1 isotope, hydrogen exists as the stable isotope DEUTERIUM and the unstable, radioactive isotope TRITIUM.Solvents: Liquids that dissolve other substances (solutes), generally solids, without any change in chemical composition, as, water containing sugar. (Grant & Hackh's Chemical Dictionary, 5th ed)Ceramides: Members of the class of neutral glycosphingolipids. They are the basic units of SPHINGOLIPIDS. They are sphingoids attached via their amino groups to a long chain fatty acyl group. They abnormally accumulate in FABRY DISEASE.Swine: 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).Equilenin: An estrogenic steroid produced by HORSES. It has a total of five double bonds in the A- and B-ring. High concentration of equilenin is found in the URINE of pregnant mares.Fatty Acids: Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)Specimen Handling: Procedures for collecting, preserving, and transporting of specimens sufficiently stable to provide accurate and precise results suitable for clinical interpretation.Hydrophobic and Hydrophilic Interactions: The thermodynamic interaction between a substance and WATER.Appetite Depressants: Agents that are used to suppress appetite.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Hydroxylation: Placing of a hydroxyl group on a compound in a position where one did not exist before. (Stedman, 26th ed)Glycoproteins: Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.Solutions: The homogeneous mixtures formed by the mixing of a solid, liquid, or gaseous substance (solute) with a liquid (the solvent), from which the dissolved substances can be recovered by physical processes. (From Grant & Hackh's Chemical Dictionary, 5th ed)Acyl-CoA Dehydrogenase: A flavoprotein oxidoreductase that has specificity for medium-chain fatty acids. It forms a complex with ELECTRON TRANSFERRING FLAVOPROTEINS and conveys reducing equivalents to UBIQUINONE.Behavior, Addictive: The observable, measurable, and often pathological activity of an organism that portrays its inability to overcome a habit resulting in an insatiable craving for a substance or for performing certain acts. The addictive behavior includes the emotional and physical overdependence on the object of habit in increasing amount or frequency.AcroleinRNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Protein Isoforms: Different forms of a protein that may be produced from different GENES, or from the same gene by ALTERNATIVE SPLICING.Mice, Inbred C57BLDioclea: A plant genus of the family FABACEAE. Members contain MANNOSE-BINDING LECTINS and dioclein.Immunoprecipitation: The aggregation of soluble ANTIGENS with ANTIBODIES, alone or with antibody binding factors such as ANTI-ANTIBODIES or STAPHYLOCOCCAL PROTEIN A, into complexes large enough to fall out of solution.Two-Dimensional Difference Gel Electrophoresis: Methods of comparing two or more samples on the same two-dimensional gel electrophoresis gel.Glycosides: Any compound that contains a constituent sugar, in which the hydroxyl group attached to the first carbon is substituted by an alcoholic, phenolic, or other group. They are named specifically for the sugar contained, such as glucoside (glucose), pentoside (pentose), fructoside (fructose), etc. Upon hydrolysis, a sugar and nonsugar component (aglycone) are formed. (From Dorland, 28th ed; From Miall's Dictionary of Chemistry, 5th ed)Molecular Conformation: The characteristic three-dimensional shape of a molecule.Saliva: The clear, viscous fluid secreted by the SALIVARY GLANDS and mucous glands of the mouth. It contains MUCINS, water, organic salts, and ptylin.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Horses: 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.StigmasterolVasoactive Intestinal Peptide: A highly basic, 28 amino acid neuropeptide released from intestinal mucosa. It has a wide range of biological actions affecting the cardiovascular, gastrointestinal, and respiratory systems and is neuroprotective. It binds special receptors (RECEPTORS, VASOACTIVE INTESTINAL PEPTIDE).Monosaccharides: Simple sugars, carbohydrates which cannot be decomposed by hydrolysis. They are colorless crystalline substances with a sweet taste and have the same general formula CnH2nOn. (From Dorland, 28th ed)Hepatocyte Nuclear Factor 3-alpha: A forkhead transcription factor that is an essential activator of GLUCAGON gene expression.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Reference Values: The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.Chromatography, Gel: Chromatography on non-ionic gels without regard to the mechanism of solute discrimination.Rabbits: 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.Calcitonin Gene-Related Peptide: Calcitonin gene-related peptide. A 37-amino acid peptide derived from the calcitonin gene. It occurs as a result of alternative processing of mRNA from the calcitonin gene. The neuropeptide is widely distributed in neural tissue of the brain, gut, perivascular nerves, and other tissue. The peptide produces multiple biological effects and has both circulatory and neurotransmitter modes of action. In particular, it is a potent endogenous vasodilator.Peptide Biosynthesis: The production of PEPTIDES or PROTEINS by the constituents of a living organism. The biosynthesis of proteins on RIBOSOMES following an RNA template is termed translation (TRANSLATION, GENETIC). There are other, non-ribosomal peptide biosynthesis (PEPTIDE BIOSYNTHESIS, NUCLEIC ACID-INDEPENDENT) mechanisms carried out by PEPTIDE SYNTHASES and PEPTIDYLTRANSFERASES. Further modifications of peptide chains yield functional peptide and protein molecules.Water: A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Least-Squares Analysis: A principle of estimation in which the estimates of a set of parameters in a statistical model are those quantities minimizing the sum of squared differences between the observed values of a dependent variable and the values predicted by the model.Liquid-Liquid Extraction: The removal of a soluble component from a liquid mixture by contact with a second liquid, immiscible with the carrier liquid, in which the component is preferentially soluble. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Lysosomal Storage Diseases: Inborn errors of metabolism characterized by defects in specific lysosomal hydrolases and resulting in intracellular accumulation of unmetabolized substrates.
Sleno L, Volmer DA (2004). "Ion activation methods for tandem mass spectrometry". Journal of mass spectrometry : JMS. 39 (10): ... Olsen JV, Macek B, Lange O, Makarov A, Horning S, Mann M (September 2007). "Higher-energy C-trap dissociation for peptide ... Laskin, Julia; Futrell, Jean H. (2005). "Activation of large lons in FT-ICR mass spectrometry". Mass Spectrometry Reviews. 24 ( ... These fragment ions can then be analyzed by a tandem mass spectrometry. CID and the fragment ions produced by CID are used for ...
As the peptides elute from the column, they are ionized and separated by m/z in the first stage of tandem mass spectrometry. ... Tandem mass spectrometry is then used to identify the peptides. Targeted proteomics using SRM and data-independent acquisition ... The charged fragments are separated in the second stage of tandem mass spectrometry. The "fingerprint" of each peptide's ... Bottom-up proteomics Mass spectrometry software Protein mass spectrometry Shotgun lipidomics Top-down proteomics Alves, P; ...
Identification of various banned small peptides in human urine using liquid chromatography tandem mass spectrometry. The ... the use of Gas Chromatography coupled with tandem Mass Spectrometry (GC-MS/MS) and Isotope-ratio mass spectrometry (IRMS) is ... Detection of Stanozolol conjugated metabolites by liquid chromatography tandem-mass spectrometry. Prednisone excretion study ... Rapid determination of urinary phthalates using liquid chromatography tandem mass spectrometry. ...
Sleno L, Volmer DA (2004). "Ion activation methods for tandem mass spectrometry". Journal of mass spectrometry : JMS. 39 (10): ... small peptides and nucleobases have been studied theoretically in some detail. Adiabatic ionization Mass-analyzed ion kinetic ... It is the science that studies ions and molecules in the gas phase, most often enabled by some form of mass spectrometry. By ... Chemical Ionization Mass Spectrometry. I. General Introduction. IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold ...
Tandem Mass Spectrometry can also be useful, especially for large molecules like glycolipids, proteins, polysaccharides or ... peptides, sugars as well as very non-polar compounds like lipids are left behind to simplify chromatography since they are not ... Structure elucidation is performed by using NMR data obtained of the compound and High Resolution Mass Spectrometry (HR-MS) ... This can be performed using Liquid Chromatography- Mass Spectrometry (LC-MS) data or Nuclear Magnetic Resonance (NMR) data ...
... of disulfide bond position in proteins and sequence analysis of cystine-bridged peptides by tandem mass spectrometry". Anal. ... Coffey, R.; Gangarosa, L.; Damstrup, L.; Dempsey, P. Basic actions of transforming growth factor- α and related peptides. Eur. ... Ma, Y. J.; Rage, F. (September 1997). "The transforming growth factor alpha gene family is involved in the neuroendocrine ...
... chromatography/tandem mass spectrometry assay for the absolute quantification of the expected circulating apelin peptides in ... "Identification and characterization of apelin peptides in bovine colostrum and milk by liquid chromatography-mass spectrometry ... a 36 amino acid peptide corresponding to the sequence 42-77 (apelin 36), a 17 amino acid peptide corresponding to the sequence ... Apelin is a peptide that was identified in 1998 by Professor M. Fujino's team. Apelin gene encodes a pre-proprotein of 77 amino ...
... the peptides separated by multidimensional liquid chromatography and analyzed by tandem mass spectrometry. Isotope coded ... Mass spectrometry and microarray produce peptide fragmentation information but do not give identification of specific proteins ... In this approach, increased throughput and sensitivity is achieved by avoiding the need for tandem mass spectrometry, and ... These programs take the peptide sequences output from mass spectrometry and microarray and return information about matching or ...
... by MALDI tandem time-of-flight mass spectrometry induces intramolecular migration of amide hydrogens in protonated peptides". ... Wales TE, Engen JR (2006). "Hydrogen exchange mass spectrometry for the analysis of protein dynamics". Mass Spectrometry ... by using collision-induced dissociation fragmentation of deuterated peptides in conjunction with tandem mass spectrometry. It ... Detecting the change in the mass of a protein upon deuteration was made possible by modern protein mass spectrometry, first ...
... peptides and mass spectrometry sequencing with ETD creates tandem mass spectra composed mostly of amino terminal peptide ... Endoproteinase Lys-C Mass spectrometry Tandem mass spectrometry Bottom-up proteomics Nonaka T, Hashimoto Y, Takio K (July 1998 ... This fragmentation pattern facilitates the applicability of these spectra for de novo peptide sequencing. ... "Straightforward ladder sequencing of peptides using a Lys-N metalloendopeptidase". Nature Methods. 5 (5): 405-7. doi:10.1038/ ...
... is a proteomics software program for tandem mass spectrometry designed for peptide sequencing, protein identification and ... 10.1074/mcp.O111.014902 (2011). Han, X.; He, L.; Xin, L.; Shan, B.; Ma, B. (2011). "PEAKS PTM: Mass Spectrometry Based ... PEAKS is commonly used for peptide identification (Protein ID) through de novo peptide sequencing assisted search engine ... Tandem and Mascot. This approach guards against false positive peptide assignments. PEAKS Q is an add-on tool for protein ...
... peptide mass data with amino acid sequence and composition information usually obtained from MS/MS tandem mass spectrometry ... Peptide Mass Fingerprint search Identifies proteins from an uploaded peak list using a technique known as peptide mass ... peptides usually fall within the limited mass range that a typical mass spectrometer can measure. Mass spectrometers measure ... Mascot is a software search engine that uses mass spectrometry data to identify proteins from peptide sequence databases. ...
It is useful for identifying disulphide bonds in tandem mass spectrometry data. Xu H, Zhang L, Freitas MA (January 2008). " ... "Identification and characterization of disulfide bonds in proteins and peptides from tandem MS data by use of the MassMatrix MS ... MassMatrix is a mass spectrometry data analysis software that uses a statistical model to achieve increased mass accuracy over ... Xu H, Freitas MA (July 2008). "Monte carlo simulation-based algorithms for analysis of shotgun proteomic data". Journal of ...
Protease Specificity Profiling by Tandem Mass Spectrometry Using Proteome-derived Peptide Libraries. Gel-Free Proteomics: ... them to be separated from trypsin generated peptides by ultrafiltration for Liquid Chromatography Tandem Mass Spectrometry (LC- ... This is thanks to trypsin treatment for mass spectrometry generating peptides specific to inactive zymogen precursors, active ... The spots corresponding to potentially substrate and cleavage products can be later elucidated using Mass Spectrometry or Edman ...
... or the same in mass, but which fragment during tandem mass spectrometry to yield reporter ions of different mass. In a typical ... During a liquid chromatography-mass spectrometry analysis, the peptides are fragmented to produce sequence-specific product ... 2003). "Tandem mass tags: a novel quantification strategy for comparative analysis of complex protein mixtures by MS/MS". Anal ... There are two types of isobaric tags commercially available: tandem mass tags (TMT) and isobaric tags for relative and absolute ...
... stationary phases sequentially into a capillary column coupled with tandem mass spectrometry (MS/MS) in the analysis of ... D.R. Nau, in: M.T.W. Hearn (Ed.), HPLC of Proteins, Peptides and Polynucleotides: Contemporary Topics and Applications, VCH ... and weak anion exchange separation materials by liquid chromatography-electrospray ionisation-tandem mass spectrometry". ... The simplest approach is to connect two commercial columns in series, which is termed a "tandem column". Another approach is " ...
... of fragmenting multiply-charged gaseous macromolecules in a mass spectrometer between the stages of tandem mass spectrometry ( ... The technique only works well for higher charge state peptide or polymer ions (z>2). However, relative to collision-induced ... ETD is used extensively with polymers and biological molecules such as proteins and peptides for sequence analysis. ... Transferring an electron causes peptide backbone cleavage into c- and z-ions while leaving labile post translational ...
Tandem mass spectrometry, on the other hand, can get sequence information from individual peptides by isolating them, colliding ... Mass spectrometry has augmented proteomics. Peptide mass fingerprinting identifies a protein by cleaving it into short peptides ... "Mass-Spectrometry-Based Draft of the Human Proteome". Nature. Kim, Min-Sik; et al. (May 2014). "A draft map of the human ... This map was generated using high-resolution Fourier-transform mass spectrometry. This study profiled 30 histologically normal ...
... is an isobaric labeling method used in quantitative proteomics by tandem mass spectrometry to determine the amount of proteins ... At the peptide level, the signals of the reporter ions of each MS/MS spectrum allow for calculating the relative abundance ( ... These samples are then pooled and usually fractionated by liquid chromatography and analyzed by tandem mass spectrometry (MS/MS ... Gafken PR, Lampe PD (2006). "Methodologies for characterizing phosphoproteins by mass spectrometry". Cell Commun. Adhes. 13 (5- ...
... is a proteomics data resource that gathers tandem mass spectrometry datasets from around the world, reprocesses ... "Integration with the human genome of peptide sequences obtained by high-throughput mass spectrometry". Genome Biology. 6 (1): - ... Peptide Atlas is one of the founding members of the ProteomeXchange Consortium. The earliest conception of PeptideAtlas began ... Institute for Systems Biology in the research lab of Ruedi Aebersold by Eric Deutsch and Sharon Chen at the Annotated Peptide ...
An immunoaffinity tandem mass spectrometry (iMALDI) assay for detection of Francisella tularensis. Anal Chim Acta. 2007 Dec 12; ... Peptide immunoaffinity enrichment and targeted mass spectrometry enables multiplex, quantitative pharmacodynamic studies of ... 2016 Jan 6. Ocaña MF, Neubert H. An immunoaffinity liquid chromatography-tandem mass spectrometry assay for the quantitation of ... Measurement of thyroglobulin by liquid chromatography-tandem mass spectrometry in serum and plasma in the presence of ...
The sequence of a protein can be determined by methods such as Edman degradation or tandem mass spectrometry. Often, however, ... Both the α-helix and the β-sheet represent a way of saturating all the hydrogen bond donors and acceptors in the peptide ... By convention, a chain under 30 amino acids is often identified as a peptide, rather than a protein. To be able to perform ... The primary structure is held together by peptide bonds that are made during the process of protein biosynthesis. The two ends ...
... his coworkers and he sequenced the first unknown peptide using soft ionization and tandem mass spectrometry (MS/MS). They also ... Int'l Foundation for Mass Spectrometry (2006). He is co-editor of the Encyclopedia of Mass Spectrometry and editor-in-chief of ... "Triple Analyzer Mass Spectrometry for High Resolution MS/MS Studies". International Journal of Mass Spectrometry and Ion ... Part A: Peptides and Proteins," Encyclopedia of Mass Spectrometry, Vol 2, Elsevier, 2005, 435 pp. Joint Ed., Ionization Methods ...
The SWIFT procedure can be used to select ions for tandem mass spectrometry experiments. Fourier-transform ion cyclotron ... "Baseline mass resolution of peptide isobars: a record for molecular mass resolution". Anal. Chem. 73 (3): 647-50. doi:10.1021/ ... Fourier-transform ion cyclotron resonance mass spectrometry is a type of mass analyzer (or mass spectrometer) for determining ... "Fourier transform ion cyclotron resonance mass spectrometry: A primer". Mass Spectrometry Reviews. 17 (1): 1-35. Bibcode: ...
A third mass analyzer then sorts the fragments produced from the peptides. Tandem MS can also be done in a single mass analyzer ... database Mass spectrometry imaging Mass spectrometry software Micro-arrays for mass spectrometry Nanoscale secondary ion mass ... An important application using tandem mass spectrometry is in protein identification. Tandem mass spectrometry enables a ... Many mass spectrometers use two or more mass analyzers for tandem mass spectrometry (MS/MS). In addition to the more common ...
... tyrosine phosphorylation sites from human T cells using immobilized metal affinity chromatography and tandem mass spectrometry ... "Exploring proteomes and analyzing protein processing by mass spectrometric identification of sorted N-terminal peptides.". Nat ... Ostendorff HP، Peirano RI، Peters MA، Schlüter A، Bossenz M، Scheffner M، Bach I (2002). "Ubiquitination-dependent cofactor ...
Dissertation: High Rate Electron Capture Dissociation Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. ... such as liquid chromatography-tandem mass spectrometry and capillary electrophoresis-tandem mass spectrometry.The analytical ... peptides and proteins. Biological mass spectrometry has become one of the most precise and sensitive techniques in peptide and ... Keywords: NATURVETENSKAP; NATURAL SCIENCES; Physics; mass spectrometry; Fourier transform ion cyclotron resonance; peptides and ...
Tandem parallel fragmentation of peptides for mass spectrometry.. Ramos AA1, Yang H, Rosen LE, Yao X. ... Parallel fragmentations of peptides in the source region and in the collision cell of tandem mass spectrometers are ... We implement the method using a quadrupole time-of-flight tandem mass spectrometer. The instrument is operated in TOF-MS mode ... The method of p2CID MS is especially useful for sequencing of large peptides with labile amide bonds and peptides with C- ...
Sequence database searches via de novo peptide sequencing by tandem mass spectrometry.. Taylor JA1, Johnson RS. ... Although sequencing of peptides from tandem mass spectra is possible, one of the frequently encountered difficulties is that ... A method is described for searching protein sequence databases using tandem mass spectra of tryptic peptides. The approach uses ... In addition, amino acid composition, peptide sequence tags and incomplete or ambiguous Edman sequence data can be used to aid ...
Simons, J.: Mechanisms for S-S and N-C- ↦ bond cleavage in peptide ECD and ETD mass spectrometry. Chem. Phys. Lett. 484(4/6), ... Jones, A. W.; Cooper, H. J. Probing the mechanisms of electron capture dissociation mass spectrometry with nitrated peptides. ... Ion-electron reaction based fragmentation methods (ExD) in tandem mass spectrometry (MS), such as electron capture dissociation ... of a new qQq-FTICR mass spectrometer for post-translational modification analysis and top-down tandem mass spectrometry of ...
... database-searchable peptide libraries is a novel approach to define the active site specificity of proteolytic enzymes we call ... Protease Specificity Profiling by Tandem Mass Spectrometry Using Proteome-Derived Peptide Libraries. ... Protease Specificity Profiling by Tandem Mass Spectrometry Using Proteome-Derived Peptide Libraries. In: Gevaert K., ... prime and non-prime active site specificities of proteases by proteomederived peptide libraries and tandem mass spectrometry. ...
Generating Peptide Sequence Tags for Peptide Identification via Tandem Mass Spectrometry ... Summary: Tandem mass spectra obtained from fragmenting peptide ions contain some peptide sequence specific information, but ... Summary: Tandem mass spectra obtained from fragmenting peptide ions contain some peptide sequence specific information, but ... statistical approach to peptide identification from clustered tandem mass ...". Abstract - Add to MetaCart statistical approach ...
... in sequencing glycated peptides by tandem mass spectrometry, ETD instrumentation is not yet available in all laboratories. In ... Both techniques offer a viable alternative to ETD for identifying glycated peptides when that method is unavailable. ... However, neutral losses of 3 H2O resulted in significantly more glycated peptide identifications during multi-stage activation ... Overall, the multi-stage activation approach produced more glycated peptide identifications, while the neutral-loss triggered ...
DeMix Workflow for Efficient Identification of Cofragmented Peptides in High Resolution Data-dependent Tandem Mass Spectrometry ... DeMix Workflow for Efficient Identification of Cofragmented Peptides in High Resolution Data-dependent Tandem Mass Spectrometry ... DeMix Workflow for Efficient Identification of Cofragmented Peptides in High Resolution Data-dependent Tandem Mass Spectrometry ... DeMix Workflow for Efficient Identification of Cofragmented Peptides in High Resolution Data-dependent Tandem Mass Spectrometry ...
Immunoglobulin G Analysis Chemical properties Liquid chromatography Peptides ... Quantification of serum IgG subclasses by use of subclass-specific tryptic peptides and liquid chromatography-tandem mass ... spectrometry.(Proteomics and Protein Markers, Report) by Clinical Chemistry; ... The use of proteotypic peptides along with liquid chromatography-tandem mass spectrometry (LC-MS/ MS), a technique that does ...
... improves the peptide/protein identification sensitivity of high resolution isobarically labeled tandem mass spectrometry data. ... improves the peptide/protein identification sensitivity of high resolution isobarically labeled tandem mass spectrometry data ... improves the peptide/protein identification sensitivity of high resolution isobarically labeled tandem mass spectrometry data ... improves the peptide/protein identification sensitivity of high resolution isobarically labeled tandem mass spectrometry data ...
... ... In addition, we also combined UVPD/CID tandem mass spectrometry technique and molecular dynamics simulations to pinpoint the ... the electronic structures of ETD-formed z-fragment ions were studied in detail using tandem mass spectrometry and molecular ... to multiply-charged peptide cations. Electron transfer dissociation (ETD) of peptides results in energetic cation radical ...
Peptide characterization by high performance liquid chromatography-tandem mass spectrometry. Authors: Bermeosolo Bidasolo, ... by high pressure liquid chromatography coupled to tandem mass spectrometry allowed the identification of 46 peptides, of which ... one of the most abundant peptides in the hydrolysate, was synthesized and its ACE-inhibitory activity measured. This peptide ... To our knowledge, this is the first time that a bioactive peptide from donkeys milk has been reported. © 2011 Elsevier Ltd. ...
Measurement of Pancreatic Polypeptide and Its Peptide Variant in Human Serum and Plasma by Immunocapture-Liquid-Chromatography- ... Tandem Mass Spectrometry. Reference Intervals and Practical Assay Considerations. Abstract. ... Polypeptide and Its Peptide Variant in Human Serum and Plasma by Immunocapture-Liquid-Chromatography-Tandem Mass Spectrometry. ... Polypeptide and its Peptide Variant in Human Serum and Plasma by Immunocapture-Liquid-Chromatography-Tandem Mass Spectrometry. ...
Tandem mass spectrometry approaches to characterizing challenging biomolecules : stapled and cyclic peptides and variants of ... Mass spectrometry has emerged as a leading tool in the field of chemistry as an analytical method for the characterization of ... but the molecule is structurally complex and offers many challenges in terms of traditional mass spectrometry characterization ... Specifically, cyclic and stapled peptides have become an intriguing class of biomolecules in drug research afforded to them ...
Fragmentation of Amino Acids and Microsolvated Peptides and Nucleotides using Electrospray Ionization Tandem Mass Spectrometry ... cations, electron transfer, excited states, mass spectrometry, peptides National Category Physical Sciences Research subject ... converted into negatively charged species in a second collision with cesium and are identified by means of mass spectrometry. ... Cα bond cleavage of singly charged microsolvated peptides after electron capture from cesium depends on the solvent molecule ...
BAM peptides, plasma samples, microextraction by packed sorbent, liquid chromatography, mass spectrometry National Category ... by packed sorbent and liquid chromatography-tandem mass spectrometry as a tool for quantification of peptides in plasma samples ... the focus was on fast extraction and determination of the peptide online using LC-MS/MS. Sorbents such as C2, C8 and ENV+ ( ...
Peptide mass fingerprinting * Peptide Fingerprinting and Tandem Mass Spectrometry * > The Principal Steps of Mass ... Peptide Mass Fingerprinting Partial Peptide Sequencing by Tandem Mass Spectrometry.. The results obtained from each of these ... Peptide Fingerprinting and Tandem Mass Spectrometry. Rainer Bischoff, University of Groningen, Netherlands. Abstract ... KeywordsPeptide Fingerprinting; Database search; Identification of a Protein;. LevelBasic. You need to be logged on to view ...
Highly complex protein mixtures can be directly analyzed after proteolysis by liquid chromatography coupled with tandem mass ... spectrometry (LC-MS/MS). In this paper, we have utilized the combination of strong cation exchange (SCX) and reversed-phase (RP ... More than 162,000 MS/MS spectra were collected with 26,815 matched to yeast peptides (7,537 unique peptides). A total of 1,504 ... Evaluation of multidimensional chromatography coupled with tandem mass spectrometry (LC/LC-MS/MS) for large-scale protein ...
Tandem Mass Spectrometry for Peptide Sequencing and Protein Identification.. Peptides were resuspended in aqueous 0.1% formic ... Amino acid-coded mass tagging (AACT) with stable isotopes followed by tandem mass spectrometry sequencing and AACT quantitation ... and peptide fragments were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and quantified by AACT (SI ... Peptide and Protein AACT Quantitation.. Mass spectra were processed and peptides were identified using the Andromeda search ...
Protein identification based on enzymatic digestion of proteins and tandem mass spectrometric (MS/MS) analysis of peptide ... Next study showed that proline-containing peptides have high tendency to place the proline residue in the N-terminal position ... Herein, it was aimed to reveal the rich chemistry lying behind the gas-phase fragmentation of peptides containing specific ... However, todays protein sequencing tools have been constructed on a limited basis of peptide fragmentation chemistry such that ...
Fast liquid chromatography coupled to electrospray tandem mass spectrometry peptide sequencing for cross-species protein ...
Gas-phase Bio-conjugation in the Tandem Mass Spectrometry of Peptides, Proteins, McLuckey, Scott A. Purdue University, West ... Gas-phase Bio-conjugation in the Tandem Mass Spectrometry of Peptides, Proteins,. McLuckey, Scott A. / Purdue University. ... Gas-phase Bio-conjugation in the Tandem Mass Spectrometry of Peptides, Proteins,. McLuckey, Scott A. / Purdue University. ... Gas-phase Bio-conjugation in the Tandem Mass Spectrometry of Peptides, Proteins,. McLuckey, Scott A. / Purdue University. ...
... cystine-knot stabilized peptides characterized by their natural abundance, sequence variability and structural plasticity. They ... cystine-knot stabilized peptides characterized by their natural abundance, sequence variability and structural plasticity. They ... De Novo Peptide Sequencing by Tandem Mass Spectrometry. Tandem mass spectra were acquired using a laser energy of 1 kV, with or ... Peptide Analysis Using MALDI-TOF Mass Spectrometry. Analysis of peptide samples were performed by MS using a MALDI-TOF/TOF 4800 ...
... ... As the theoretical pI of peptides can be calculated, the pI of the identified peptides can be used to validate the peptide ... High sample complexity is one of the major challenges in mass spectrometry-based proteomics today. Despite massive improvement ... This is done by selectively analyzing a sub-fraction of peptides with an acidic pI. The pI range is chosen as it has previously ...
Mass spectrometric analysis of trace amounts of peptides may be problematic due to the insufficient ionization efficiency ... Peptides Labeled with Pyridinium Salts for Sensitive Detection and Sequencing by Electrospray Tandem Mass Spectrometry Waliczek ... Mass spectrometric analysis of trace amounts of peptides may be problematic due to the insufficient ionization efficiency ... Other advantages of the proposed ionization enhancers are the simplicity of derivatization of peptides and the possibility of ...
  • Parallel fragmentations of peptides in the source region and in the collision cell of tandem mass spectrometers are sequentially combined to develop parallel collision-induced-dissociation mass spectrometry (p2CID MS). Compared to MS/MS spectra, the p2CID mass spectra show increased signal intensities (2-400-fold) and number of sequence ions. (nih.gov)
  • While electron transfer dissociation (ETD) has been shown to outperform collision-induced dissociation (CID) in sequencing glycated peptides by tandem mass spectrometry, ETD instrumentation is not yet available in all laboratories. (unt.edu)
  • The generation of these radicals can be accomplished via several methods including electron-based methods such as electron transfer dissociation or electron capture dissociation, collision-induced dissociation of transition metal-peptide complexes, photodissociation of iodinated peptide ions, etc. (washington.edu)
  • Herein, it was aimed to reveal the rich chemistry lying behind the gas-phase fragmentation of peptides containing specific residues using MS/MS and collision induced dissociation (CID) analysis. (iyte.edu.tr)
  • Collision-induced dissociation (CID), also known as collisionally activated dissociation (CAD), is a mass spectrometry technique to induce fragmentation of molecular ions in the gas phase. (wikipedia.org)
  • Sustained off-resonance irradiation collision-induced dissociation (SORI-CID) is a CID technique used in Fourier transform ion cyclotron resonance mass spectrometry which involves accelerating the ions in cyclotron motion (in a circle inside of an ion trap) and then increasing the pressure resulting collisions that produce CID fragments. (wikipedia.org)
  • The procedure comprises (i) screening experiments to identify the most important parameters, (ii) LC studies to ensure sufficient chromatographic separation, (iii) extended infusion experiments in order to maximize precursor signal(s), and in the case of tandem MS (iv) extended infusion experiments to determine optimal conditions for collision induced dissociation and when applicable also ion trap settings. (diva-portal.org)
  • Lipid A becomes a biologically relevant molecule to study as its function within LPS is directly related to the infectious and toxic properties of gram-negative bacteria, but the molecule is structurally complex and offers many challenges in terms of traditional mass spectrometry characterization. (utexas.edu)
  • This strategy allows the characterization of the most relevant peptides and minimizes the risk of false-positive identifications, reducing analysis time and costs, with the advantage of obtaining a lot of important information by a single LC-MS/MS run. (unifg.it)
  • Immunopeptidomes promise novel surface markers as ideal immunotherapy targets, but their characterization by mass spectrometry (MS) remains challenging. (stanford.edu)
  • Although sequencing of peptides from tandem mass spectra is possible, one of the frequently encountered difficulties is that several alternative sequences can be deduced from one spectrum. (nih.gov)
  • Suited for all protease classes except carboxyproteases and those aminoproteases and dipeptidases requiring a free α-amine for cleavage, PICS simultaneously profiles the specificity of prime and nonprime positions and directly determines scissile peptide bonds of up to hundreds of cleavage site sequences in a single experiment. (springer.com)
  • Chapter 2 investigates the photoreactivity of z-fragment ions originating from model peptide sequences AAXAR and AAXK, where X is a residue of interest analyzed by both UV-Vis photodissociation at 355 nm and computational methods. (washington.edu)
  • Although the N-terminal peptide did not show significant similarity to any other sequences, it was predicted to have an overall helical structure and high amphipathicity, both of which are typical features of many AMPs. (jimmunol.org)
  • For example, by the mid-1990s, a variety of mass spectrometry-based strategies had essentially replaced the Edman degradation as the mainstream method for determining the amino acid sequences of polypeptides. (sciencemag.org)
  • Obviously, this strategy could not identify peptide and protein sequences that are absent from a reference database. (pubmedcentralcanada.ca)
  • In order to have more specific tools available to approach amyloidogenesis in Alzheimer's disease (AD), we have produced several polyclonal and monoclonal antibodies that recognize specific sequences of the amyloid � (A�) peptide. (ebscohost.com)
  • These changes include addition of aminoarabinose and palmitate to the lipid A moiety of lipopolysaccharide (LPS) ( 16 , 19 , 21 ), which promotes resistance to polymyxin ( 15 , 19 ), alpha-helical antimicrobial peptides, and protegrin, a β-sheet antimicrobial peptide ( 21 ). (asm.org)
  • 16) demonstrated that IgG glycoforms can also be monitored along with subclass-specific proteotypic peptides by use of LCMS/MS. Here we present an assay based on subclass-specific tryptic peptides and LC-MS/MS that performs on par with the current nephelometry assay and can report the concentration of all 4 IgG subclasses and total IgG in a single analysis. (thefreelibrary.com)
  • In addition, we have also applied computational methods with different density functionals and basis sets in conjunction with molecular dynamics simulations to gain further insights regarding the structures of ETD-formed peptide cation radicals. (washington.edu)
  • In the first part of this work, which includes Chapters 2-5, the electronic structures of ETD-formed z-fragment ions were studied in detail using tandem mass spectrometry and molecular dynamics simulations. (washington.edu)
  • Depending on their molecular weight, peptides may be transported through intestinal-expressed transporters across the enterocytes [ 7 ]. (hindawi.com)
  • The direct observation of isocyanate binding to the N-terminus of peptides under these experimental conditions is in good agreement with previous studies on the relative reaction rate of isocyanate with amino acid functional groups. (cdc.gov)
  • In this study, we evaluated different advanced CID techniques (i.e., neutral-loss triggered MS3 and multi-stage activation) during LC-MSn analyses of Amadori-modified peptides enriched from human serum glycated in vitro. (unt.edu)
  • Serum expression levels of such peptides were then quantitated by MRM. (biomedcentral.com)
  • Mass spectrometry was restricted for a long time to small and thermostable compounds because of the lack of effective techniques to softly ionize and transfer the ionized molecules from the condensed phase into the gas phase without excessive fragmentation. (sciencemag.org)
  • Addition of multiple isocyanates to the peptide occurs via polymerization of the isocyanate at the N-terminus, rather than via addition of multiple isocyanate molecules to varied residues within the peptide. (cdc.gov)
  • During neutral-loss triggered MS3 experiments, MS3 scans triggered by neutral-losses of 3 H2O or 3 H2O + HCHO produced similar results in terms of glycated peptide identifications. (unt.edu)
  • However, neutral losses of 3 H2O resulted in significantly more glycated peptide identifications during multi-stage activation experiments. (unt.edu)
  • Overall, the multi-stage activation approach produced more glycated peptide identifications, while the neutral-loss triggered MS3 approach resulted in much higher specificity. (unt.edu)
  • The membranes were trypsin digested and the peptides were analyzed using LC-MS/MS under optimized conditions. (hindawi.com)
  • Using the purified native peptide, this cleavage was found to be mediated by trypsin after synthesis. (jimmunol.org)
  • Comparison of the peptide-binding motifs of inhibitor-sensitive and -resistant class I alleles further suggested that inhibitor-resistant proteolytic activities display a wide diversity of cleavage specificities, including a trypsin-like activity. (jimmunol.org)
  • A promising alternative method to antibody mediated approaches is mass spectrometry based multiple reaction monitoring (MRM) that allows accurately quantifying peptide. (biomedcentral.com)
  • We use mass spectrometry-based approaches which can do more than simply determining the identity of a protein isolated in a polyacrylamide gel -- rapidly advancing technologies are allowing us to measure dynamic changes in protein abundances, post-translational modification states, splice isoforms, interaction partners, and localization across multiple cell states. (stanford.edu)
  • The protein abundance is typically measured based on calibration curve generated using the unique synthetic peptide as an external standard and the stable isotope labeled peptide (SIL) as an internal standard [ 3 ]. (hindawi.com)
  • A pipeline with an R package, assigned as a PGA utility, was developed that enables automated treatment to the tandem mass spectrometry (MS/MS) data acquired from different MS platforms and construction of customized protein databases based on RNA-Seq data with or without a reference genome guide. (pubmedcentralcanada.ca)
  • A technique was also presented for how to restore the resolution in mass spectra obtained with a hemispherical electrostatic analyzer followed by a position sensitive detector (micro-channel plate equipped with a resistive anode). (diva-portal.org)
  • On-line HPLC-ion spray mass spectrometry was more practical and useful than conventional HPLC alone for characterizing the products of these cyclization reactions. (elsevier.com)
  • Peptide byproducts could be identified from the series of multiply charged ions observed, even when some of these peptides eluted from the HPLC with similar retention times. (elsevier.com)
  • Thin layer chromatography, RP-HPLC-DAD and tandem mass spectrometry (LC-MS/MS), were employed to identify the chemical constituents in the ethyl acetate fractions of the stem bark and wood. (mdpi.com)
  • A major component from the two sources appears to be identical by HPLC and UV- visible spectrometry. (usda.gov)
  • Therefore, we investigated if the use of SILAC protein as an internal standard would result in greater assay precision than using the SIL peptide. (hindawi.com)