Cellular proteins and protein complexes that transport amino acids across biological membranes.

A sodium-independent neutral amino acid transporter system with specificity for large amino acids. One of the functions of the transporter system is to supply large neutral amino acids to the brain.

Amino acid transporter systems capable of transporting basic amino acids (AMINO ACIDS, BASIC).

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.

The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.

A group of compounds that are derivatives of the amino acid 2-amino-2-methylpropanoic acid.

A sodium-dependent neutral amino acid transporter that accounts for most of the sodium-dependent neutral amino acid uptake by mammalian cells. The preferred substrates for this transporter system include ALANINE; SERINE; and GLUTAMINE.

Amino acid transporter systems capable of transporting neutral amino acids (AMINO ACIDS, NEUTRAL).

The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.

A ubiquitous sodium-dependent neutral amino acid transporter. The preferred substrates for this transporter system include ALANINE; SERINE; and CYSTEINE.

An essential branched-chain amino acid important for hemoglobin formation.

'Amino Acid Transport System y+', also known as System Y+, is a sodium-independent cationic amino acid transporter that mediates the uptake of primarily basic amino acids, such as arginine and lysine, into cells through a facilitated diffusion process.

An amino acid formed in vivo by the degradation of dihydrouracil and carnosine. Since neuronal uptake and neuronal receptor sensitivity to beta-alanine have been demonstrated, the compound may be a false transmitter replacing GAMMA-AMINOBUTYRIC ACID. A rare genetic disorder, hyper-beta-alaninemia, has been reported.

A heterodimeric protein that is a cell surface antigen associated with lymphocyte activation. The initial characterization of this protein revealed one identifiable heavy chain (ANTIGENS, CD98 HEAVY CHAIN) and an indeterminate smaller light chain. It is now known that a variety of light chain subunits (ANTIGENS, CD98 LIGHT CHAINS) can dimerize with the heavy chain. Depending upon its light chain composition a diverse array of functions can be found for this protein. Functions include: type L amino acid transport, type y+L amino acid transport and regulation of cellular fusion.

Amino acids with uncharged R groups or side chains.

A class of amino acids characterized by a closed ring structure.

Amino acids which have a branched carbon chain.

Transport proteins that carry specific substances in the blood or across cell membranes.

A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.

An essential aromatic amino acid that is a precursor of MELANIN; DOPAMINE; noradrenalin (NOREPINEPHRINE), and THYROXINE.

The rate dynamics in chemical or physical systems.

A non-essential amino acid that occurs in high levels in its free state in plasma. It is produced from pyruvate by transamination. It is involved in sugar and acid metabolism, increases IMMUNITY, and provides energy for muscle tissue, BRAIN, and the CENTRAL NERVOUS SYSTEM.

Amino Acid Transport System y+L is a sodium-independent cationic amino acid transporter, primarily responsible for the uptake of arginine and lysine into cells via a proton gradient. This system plays a crucial role in cellular metabolism, growth, and survival, and its dysfunction has been implicated in various disease states, including cancer and neurodegenerative disorders.

One of the three domains of life (the others being Eukarya and ARCHAEA), also called Eubacteria. They are unicellular prokaryotic microorganisms which generally possess rigid cell walls, multiply by cell division, and exhibit three principal forms: round or coccal, rodlike or bacillary, and spiral or spirochetal. Bacteria can be classified by their response to OXYGEN: aerobic, anaerobic, or facultatively anaerobic; by the mode by which they obtain their energy: chemotrophy (via chemical reaction) or PHOTOTROPHY (via light reaction); for chemotrophs by their source of chemical energy: CHEMOLITHOTROPHY (from inorganic compounds) or chemoorganotrophy (from organic compounds); and by their source for CARBON; NITROGEN; etc.; HETEROTROPHY (from organic sources) or AUTOTROPHY (from CARBON DIOXIDE). They can also be classified by whether or not they stain (based on the structure of their CELL WALLS) with CRYSTAL VIOLET dye: gram-negative or gram-positive.

Membrane proteins whose primary function is to facilitate the transport of molecules across a biological membrane. Included in this broad category are proteins involved in active transport (BIOLOGICAL TRANSPORT, ACTIVE), facilitated transport and ION CHANNELS.

A cytotoxic sulfhydryl reagent that inhibits several subcellular metabolic systems and is used as a tool in cellular physiology.

A non-essential amino acid present abundantly throughout the body and is involved in many metabolic processes. It is synthesized from GLUTAMIC ACID and AMMONIA. It is the principal carrier of NITROGEN in the body and is an important energy source for many cells.

A non-essential amino acid that is synthesized from GLUTAMIC ACID. It is an essential component of COLLAGEN and is important for proper functioning of joints and tendons.

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.

An essential branched-chain aliphatic amino acid found in many proteins. It is an isomer of LEUCINE. It is important in hemoglobin synthesis and regulation of blood sugar and energy levels.

A broad category of membrane transport proteins that specifically transport FREE FATTY ACIDS across cellular membranes. They play an important role in LIPID METABOLISM in CELLS that utilize free fatty acids as an energy source.

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 branched-chain essential amino acid that has stimulant activity. It promotes muscle growth and tissue repair. It is a precursor in the penicillin biosynthetic pathway.

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.

An essential amino acid that is physiologically active in the L-form.

An essential amino acid. It is often added to animal feed.

An enzyme that activates leucine with its specific transfer RNA. EC 6.1.1.4.

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 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.

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.

The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.

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)

The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.

Amino acid transporter systems capable of transporting acidic amino acids (AMINO ACIDS, ACIDIC).

An essential amino acid that is necessary for normal growth in infants and for NITROGEN balance in adults. It is a precursor of INDOLE ALKALOIDS in plants. It is a precursor of SEROTONIN (hence its use as an antidepressant and sleep aid). It can be a precursor to NIACIN, albeit inefficiently, in mammals.

Derivatives of GLUTAMIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the 2-aminopentanedioic acid structure.

The commonest and widest ranging species of the clawed "frog" (Xenopus) in Africa. This species is used extensively in research. There is now a significant population in California derived from escaped laboratory animals.

Proteins found in any species of bacterium.

A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.

The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.

Female germ cells derived from OOGONIA and termed OOCYTES when they enter MEIOSIS. The primary oocytes begin meiosis but are arrested at the diplotene state until OVULATION at PUBERTY to give rise to haploid secondary oocytes or ova (OVUM).

An essential amino acid that is required for the production of HISTAMINE.

Established cell cultures that have the potential to propagate indefinitely.

Dicarboxylic acids are organic compounds containing two carboxyl (-COOH) groups in their structure, making them capable of forming salts and esters by losing two hydrogen ions.

The product of conjugation of cholic acid with taurine. Its sodium salt is the chief ingredient of the bile of carnivorous animals. It acts as a detergent to solubilize fats for absorption and is itself absorbed. It is used as a cholagogue and cholerectic.

The functional hereditary units of BACTERIA.

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.

Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.

A sulfhydryl reagent that is widely used in experimental biochemical studies.

A CD98 antigen light chain that when heterodimerized with CD98 antigen heavy chain (ANTIGENS, CD98 HEAVY CHAIN) forms a protein that mediates sodium-independent L-type amino acid transport.

Diamino acids are a type of modified amino acids containing two amino groups, which can be found in various biological molecules and play important roles in various cellular processes, such as nitrogen fixation and protein synthesis.

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.

A non-essential amino acid. It is found primarily in gelatin and silk fibroin and used therapeutically as a nutrient. It is also a fast inhibitory neurotransmitter.

A family of light chains that bind to the CD98 heavy chain (ANTIGENS, CD98 HEAVY CHAIN) to form a heterodimer. They convey functional specificity to the protein.

Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.

A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.

An inherited disorder due to defective reabsorption of CYSTINE and other BASIC AMINO ACIDS by the PROXIMAL RENAL TUBULES. This form of aminoaciduria is characterized by the abnormally high urinary levels of cystine; LYSINE; ARGININE; and ORNITHINE. Mutations involve the amino acid transport protein gene SLC3A1.

A transmembrane glycoprotein subunit that can dimerize with a variety of light chain subunits (ANTIGENS, CD98 LIGHT CHAINS). This protein subunit serves a diverse array of functions including amino acid transport and cell fusion. Its function is altered depending which of the light chain subunits it interacts with.

Bacteria which lose crystal violet stain but are stained pink when treated by Gram's method.

The naturally occurring or experimentally induced replacement of one or more AMINO ACIDS in a protein with another. If a functionally equivalent amino acid is substituted, the protein may retain wild-type activity. Substitution may also diminish, enhance, or eliminate protein function. Experimentally induced substitution is often used to study enzyme activities and binding site properties.

A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement.

An autosomal recessive disorder due to defective absorption of NEUTRAL AMINO ACIDS by both the intestine and the PROXIMAL RENAL TUBULES. The abnormal urinary loss of TRYPTOPHAN, a precursor of NIACIN, leads to a NICOTINAMIDE deficiency, PELLAGRA-like light-sensitive rash, CEREBELLAR ATAXIA, emotional instability, and aminoaciduria. Mutations involve the neurotransmitter transporter gene SLC6A19.

Bacteria which retain the crystal violet stain when treated by Gram's method.

Organic compounds that contain two nitro groups attached to a phenol.

Unstable isotopes of carbon that decay or disintegrate emitting radiation. C atoms with atomic weights 10, 11, and 14-16 are radioactive carbon isotopes.

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.

A sulfur-containing essential L-amino acid that is important in many body functions.

Minute projections of cell membranes which greatly increase the surface area of the cell.

A family of gram-negative bacteria usually found in soil or water and including many plant pathogens and a few animal pathogens.

The distal and narrowest portion of the SMALL INTESTINE, between the JEJUNUM and the ILEOCECAL VALVE of the LARGE INTESTINE.

Methylglucosides are a type of sugar alcohols, specifically methylated glucose derivatives, which are used as sweetening agents, excipients, and solvents in pharmaceutical and cosmetic products due to their low toxicity and good solubility in water.

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.

Derivatives of phenylacetic acid. Included under this heading are a variety of acid forms, salts, esters, and amides that contain the benzeneacetic acid structure. Note that this class of compounds should not be confused with derivatives of phenyl acetate, which contain the PHENOL ester of ACETIC ACID.

The relationships of groups of organisms as reflected by their genetic makeup.

A group of compounds that are methyl derivatives of the amino acid TYROSINE.

Antibiotic substance isolated from streptomycin-producing strains of Streptomyces griseus. It acts by inhibiting elongation during protein synthesis.

'Anaerobic Bacteria' are types of bacteria that do not require oxygen for growth and can often cause diseases in humans, including dental caries, gas gangrene, and tetanus, among others.

The movement of ions across energy-transducing cell membranes. Transport can be active, passive or facilitated. Ions may travel by themselves (uniport), or as a group of two or more ions in the same (symport) or opposite (antiport) directions.

Membrane transporters that co-transport two or more dissimilar molecules in the same direction across a membrane. Usually the transport of one ion or molecule is against its electrochemical gradient and is "powered" by the movement of another ion or molecule with its electrochemical gradient.

The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.

The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.

Single-stranded complementary DNA synthesized from an RNA template by the action of RNA-dependent DNA polymerase. cDNA (i.e., complementary DNA, not circular DNA, not C-DNA) is used in a variety of molecular cloning experiments as well as serving as a specific hybridization probe.

Deoxyribonucleic acid that makes up the genetic material of bacteria.

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.

A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.

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)

The directed transport of ORGANELLES and molecules along nerve cell AXONS. Transport can be anterograde (from the cell body) or retrograde (toward the cell body). (Alberts et al., Molecular Biology of the Cell, 3d ed, pG3)

A family of POTASSIUM and SODIUM-dependent acidic amino acid transporters that demonstrate a high affinity for GLUTAMIC ACID and ASPARTIC ACID. Several variants of this system are found in neuronal tissue.

One of the non-essential amino acids commonly occurring in the L-form. It is found in animals and plants, especially in sugar cane and sugar beets. It may be a neurotransmitter.

A large group of membrane transport proteins that shuttle MONOSACCHARIDES across CELL MEMBRANES.

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.

Elements of limited time intervals, contributing to particular results or situations.

Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.

The parts of a macromolecule that directly participate in its specific combination with another molecule.

Disorders characterized by defective transport of amino acids across cell membranes. These include deficits in transport across brush-border epithelial cell membranes of the small intestine (MICROVILLI) and KIDNEY TUBULES; transport across the basolateral membrane; and transport across the membranes of intracellular organelles. (From Nippon Rinsho 1992 Jul;50(7):1587-92)

Amino acids that are not synthesized by the human body in amounts sufficient to carry out physiological functions. They are obtained from dietary foodstuffs.

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.

A highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products. It includes a fetal portion (CHORIONIC VILLI) derived from TROPHOBLASTS and a maternal portion (DECIDUA) derived from the uterine ENDOMETRIUM. The placenta produces an array of steroid, protein and peptide hormones (PLACENTAL HORMONES).

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.

Organic or inorganic compounds that contain the -N3 group.

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.

Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.

Proteins prepared by recombinant DNA technology.

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 element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.

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)

A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE.

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.

A non-essential amino acid naturally occurring in the L-form. Glutamic acid is the most common excitatory neurotransmitter in the CENTRAL NERVOUS SYSTEM.

Genetically engineered MUTAGENESIS at a specific site in the DNA molecule that introduces a base substitution, or an insertion or deletion.

The middle portion of the SMALL INTESTINE, between DUODENUM and ILEUM. It represents about 2/5 of the remaining portion of the small intestine below duodenum.

A non-metabolizable glucose analogue that is not phosphorylated by hexokinase. 3-O-Methylglucose is used as a marker to assess glucose transport by evaluating its uptake within various cells and organ systems. (J Neurochem 1993;60(4):1498-504)

Aerobic bacteria are types of microbes that require oxygen to grow and reproduce, and use it in the process of respiration to break down organic matter and produce energy, often found in environments where oxygen is readily available such as the human body's skin, mouth, and intestines.

Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.

The process by which ELECTRONS are transported from a reduced substrate to molecular OXYGEN. (From Bennington, Saunders Dictionary and Encyclopedia of Laboratory Medicine and Technology, 1984, p270)

A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.

A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.

The section of the alimentary canal from the STOMACH to the ANAL CANAL. It includes the LARGE INTESTINE and SMALL INTESTINE.

An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.

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.

Short sequences (generally about 10 base pairs) of DNA that are complementary to sequences of messenger RNA and allow reverse transcriptases to start copying the adjacent sequences of mRNA. Primers are used extensively in genetic and molecular biology techniques.

A high-affinity, low capacity system y+ amino acid transporter found ubiquitously. It has specificity for the transport of ARGININE; LYSINE; and ORNITHINE. It may also act as an ecotropic leukemia retroviral receptor.

Uptake of substances through the lining of the INTESTINES.

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).

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.

Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.

A non-essential amino acid occurring in natural form as the L-isomer. It is synthesized from GLYCINE or THREONINE. It is involved in the biosynthesis of PURINES; PYRIMIDINES; and other amino acids.

A family of MEMBRANE TRANSPORT PROTEINS that require ATP hydrolysis for the transport of substrates across membranes. The protein family derives its name from the ATP-binding domain found on the protein.

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.

An amino acid produced in the urea cycle by the splitting off of urea from arginine.

Phloretin is a dihydrochalcone flavonoid, primarily found in apple tree leaves and roots, which exhibits antioxidant properties and has been studied for its potential role in skin care, cancer prevention, and diabetes management, although more research is needed to fully understand its mechanisms and clinical applications.

A conditionally essential nutrient, important during mammalian development. It is present in milk but is isolated mostly from ox bile and strongly conjugates bile acids.

The portion of the GASTROINTESTINAL TRACT between the PYLORUS of the STOMACH and the ILEOCECAL VALVE of the LARGE INTESTINE. It is divisible into three portions: the DUODENUM, the JEJUNUM, and the ILEUM.

A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1).

The sum of the weight of all the atoms in a molecule.

Inorganic compounds derived from hydrochloric acid that contain the Cl- ion.

Constituent of 30S subunit prokaryotic ribosomes containing 1600 nucleotides and 21 proteins. 16S rRNA is involved in initiation of polypeptide synthesis.

The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.

Proteins involved in the transport of organic anions. They play an important role in the elimination of a variety of endogenous substances, xenobiotics and their metabolites from the body.

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.

A thiol-containing non-essential amino acid that is oxidized to form CYSTINE.

2-Deoxy-D-arabino-hexose. An antimetabolite of glucose with antiviral activity.

A dextrodisaccharide from malt and starch. It is used as a sweetening agent and fermentable intermediate in brewing. (Grant & Hackh's Chemical Dictionary, 5th ed)

Membrane proteins whose primary function is to facilitate the transport of negatively charged molecules (anions) across a biological membrane.

A serotype of Salmonella enterica that is a frequent agent of Salmonella gastroenteritis in humans. It also causes PARATYPHOID FEVER.

Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.

Tritium is an isotope of hydrogen (specifically, hydrogen-3) that contains one proton and two neutrons in its nucleus, making it radioactive with a half-life of about 12.3 years, and is used in various applications including nuclear research, illumination, and dating techniques due to its low energy beta decay.

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)

A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.

Cells lining the outside of the BLASTOCYST. After binding to the ENDOMETRIUM, trophoblasts develop into two distinct layers, an inner layer of mononuclear cytotrophoblasts and an outer layer of continuous multinuclear cytoplasm, the syncytiotrophoblasts, which form the early fetal-maternal interface (PLACENTA).

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).

Use of restriction endonucleases to analyze and generate a physical map of genomes, genes, or other segments of DNA.

The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.

Methylglycosides are glycosides with a methanol group (CH3-) replacing the hydrogen atom on the glycosidic oxygen, which can be found in various natural sources and have potential applications as sweetening agents or in pharmaceuticals.

Negatively charged atoms, radicals or groups of atoms which travel to the anode or positive pole during electrolysis.

A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.

The outer zone of the KIDNEY, beneath the capsule, consisting of KIDNEY GLOMERULUS; KIDNEY TUBULES, DISTAL; and KIDNEY TUBULES, PROXIMAL.

Lining of the INTESTINES, consisting of an inner EPITHELIUM, a middle LAMINA PROPRIA, and an outer MUSCULARIS MUCOSAE. In the SMALL INTESTINE, the mucosa is characterized by a series of folds and abundance of absorptive cells (ENTEROCYTES) with MICROVILLI.

Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.

Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.

The decrease in a measurable parameter of a PHYSIOLOGICAL PROCESS, including cellular, microbial, and plant; immunological, cardiovascular, respiratory, reproductive, urinary, digestive, neural, musculoskeletal, ocular, and skin physiological processes; or METABOLIC PROCESS, including enzymatic and other pharmacological processes, by a drug or other chemical.

An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.

Any method used for determining the location of and relative distances between genes on a chromosome.

A large collection of DNA fragments cloned (CLONING, MOLECULAR) from a given organism, tissue, organ, or cell type. It may contain complete genomic sequences (GENOMIC LIBRARY) or complementary DNA sequences, the latter being formed from messenger RNA and lacking intron sequences.

The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).

An element in the alkali metals family. It has the atomic symbol Li, atomic number 3, and atomic weight [6.938; 6.997]. Salts of lithium are used in treating BIPOLAR DISORDER.

Iodinated derivatives of acetic acid. Iodoacetates are commonly used as alkylating sulfhydryl reagents and enzyme inhibitors in biochemical research.

Proteins obtained from ESCHERICHIA COLI.

Enzymes that catalyze the formation of acyl-CoA derivatives. EC 6.2.1.

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)

Steroid acids and salts. The primary bile acids are derived from cholesterol in the liver and usually conjugated with glycine or taurine. The secondary bile acids are further modified by bacteria in the intestine. They play an important role in the digestion and absorption of fat. They have also been used pharmacologically, especially in the treatment of gallstones.

An essential amino acid occurring naturally in the L-form, which is the active form. It is found in eggs, milk, gelatin, and other proteins.

The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.

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.

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).

The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.

Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.

Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.

A subclass of ORGANIC ANION TRANSPORTERS whose transport of organic anions is driven either directly or indirectly by a gradient of sodium ions.

Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.

The uptake of naked or purified DNA by CELLS, usually meaning the process as it occurs in eukaryotic cells. It is analogous to bacterial transformation (TRANSFORMATION, BACTERIAL) and both are routinely employed in GENE TRANSFER TECHNIQUES.

The concentration of osmotically active particles in solution expressed in terms of osmoles of solute per liter of solution. Osmolality is expressed in terms of osmoles of solute per kilogram of solvent.

Minute intercellular channels that occur between liver cells and carry bile towards interlobar bile ducts. Also called bile capillaries.

Periplasmic proteins that scavenge or sense diverse nutrients. In the bacterial environment they usually couple to transporters or chemotaxis receptors on the inner bacterial membrane.

In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.

One or more layers of EPITHELIAL CELLS, supported by the basal lamina, which covers the inner or outer surfaces of the body.

A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.

Derivatives of SUCCINIC ACID. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain a 1,4-carboxy terminated aliphatic structure.

Amino acids containing an aromatic side chain.

A transplantable, poorly differentiated malignant tumor which appeared originally as a spontaneous breast carcinoma in a mouse. It grows in both solid and ascitic forms.

A family of plasma membrane neurotransmitter transporter proteins that couple the uptake of GLUTAMATE with the import of SODIUM ions and PROTONS and the export of POTASSIUM ions. In the CENTRAL NERVOUS SYSTEM they regulate neurotransmission through synaptic reuptake of the excitatory neurotransmitter glutamate. Outside the central nervous system they function as signal mediators and regulators of glutamate metabolism.

Specialized non-fenestrated tightly-joined ENDOTHELIAL CELLS with TIGHT JUNCTIONS that form a transport barrier for certain substances between the cerebral capillaries and the BRAIN tissue.