Tunicamycin
An N-acetylglycosamine containing antiviral antibiotic obtained from Streptomyces lysosuperificus. It is also active against some bacteria and fungi, because it inhibits the glucosylation of proteins. Tunicamycin is used as tool in the study of microbial biosynthetic mechanisms.
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.
Glucosamine
Glycoproteins
Polysaccharides
Polysaccharides are complex carbohydrates consisting of long, often branched chains of repeating monosaccharide units joined together by glycosidic bonds, which serve as energy storage molecules (e.g., glycogen), structural components (e.g., cellulose), and molecular recognition sites in various biological systems.
Dolichol Phosphates
Phosphoric acid esters of dolichol.
Congenital Disorders of Glycosylation
Dolichol
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.
Protein Modification, Translational
Any of the enzymatically catalyzed modifications of the individual AMINO ACIDS of PROTEINS, and enzymatic cleavage or crosslinking of peptide chains that occur pre-translationally (on the amino acid component of AMINO ACYL TRNA), co-translationally (during the process of GENETIC TRANSLATION), or after translation is completed (POST-TRANSLATIONAL PROTEIN PROCESSING).
Guanosine Diphosphate Mannose
Mannose
A hexose or fermentable monosaccharide and isomer of glucose from manna, the ash Fraxinus ornus and related plants. (From Grant & Hackh's Chemical Dictionary, 5th ed & Random House Unabridged Dictionary, 2d ed)
Uridine Diphosphate N-Acetylglucosamine
Serves as the biological precursor of insect chitin, of muramic acid in bacterial cell walls, and of sialic acids in mammalian glycoproteins.
Acetylglucosamine
The N-acetyl derivative of glucosamine.
Protein Processing, Post-Translational
Any of various enzymatically catalyzed post-translational modifications of PEPTIDES or PROTEINS in the cell of origin. These modifications include carboxylation; HYDROXYLATION; ACETYLATION; PHOSPHORYLATION; METHYLATION; GLYCOSYLATION; ubiquitination; oxidation; proteolysis; and crosslinking and result in changes in molecular weight and electrophoretic motility.
Glycomics
The systematic study of the structure and function of the complete set of glycans (the glycome) produced in a single organism and identification of all the genes that encode glycoproteins.
Glycosyltransferases
Enzymes that catalyze the transfer of glycosyl groups to an acceptor. Most often another carbohydrate molecule acts as an acceptor, but inorganic phosphate can also act as an acceptor, such as in the case of PHOSPHORYLASES. Some of the enzymes in this group also catalyze hydrolysis, which can be regarded as transfer of a glycosyl group from the donor to water. Subclasses include the HEXOSYLTRANSFERASES; PENTOSYLTRANSFERASES; SIALYLTRANSFERASES; and those transferring other glycosyl groups. EC 2.4.
Glycopeptides
Campylobacter jejuni
Carbohydrate Metabolism, Inborn Errors
Inborn errors of carbohydrate metabolism are genetic disorders that result from enzyme deficiencies or transport defects in the metabolic pathways responsible for breaking down and processing carbohydrates, leading to accumulation of toxic intermediates or energy deficits, and typically presenting with multisystem clinical manifestations.
Carbohydrate Sequence
Mannosyltransferases
Hexosamines
Hexosamines are amino sugars that are formed by the substitution of an amino group for a hydroxyl group in a hexose sugar, playing crucial roles in various biological processes such as glycoprotein synthesis and protein folding.
Endoplasmic Reticulum
A system of cisternae in the CYTOPLASM of many cells. In places the endoplasmic reticulum is continuous with the plasma membrane (CELL MEMBRANE) or outer membrane of the nuclear envelope. If the outer surfaces of the endoplasmic reticulum membranes are coated with ribosomes, the endoplasmic reticulum is said to be rough-surfaced (ENDOPLASMIC RETICULUM, ROUGH); otherwise it is said to be smooth-surfaced (ENDOPLASMIC RETICULUM, SMOOTH). (King & Stansfield, A Dictionary of Genetics, 4th ed)
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.
Asparagine
A non-essential amino acid that is involved in the metabolic control of cell functions in nerve and brain tissue. It is biosynthesized from ASPARTIC ACID and AMMONIA by asparagine synthetase. (From Concise Encyclopedia Biochemistry and Molecular Biology, 3rd ed)
Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase
An amidohydrolase that removes intact asparagine-linked oligosaccharide chains from glycoproteins. It requires the presence of more than two amino-acid residues in the substrate for activity. This enzyme was previously listed as EC 3.2.2.18.
N-Acetylglucosaminyltransferases
Mannose-6-Phosphate Isomerase
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.
Uridine Diphosphate Glucose
A key intermediate in carbohydrate metabolism. Serves as a precursor of glycogen, can be metabolized into UDPgalactose and UDPglucuronic acid which can then be incorporated into polysaccharides as galactose and glucuronic acid. Also serves as a precursor of sucrose lipopolysaccharides, and glycosphingolipids.
Phosphotransferases (Phosphomutases)
A group of enzymes that catalyze an intramolecular transfer of a phosphate group. It has been shown in some cases that the enzyme has a functional phosphate group, which can act as the donor. These were previously listed under PHOSPHOTRANSFERASES (EC 2.7.-). (From Enzyme Nomenclature, 1992) EC 5.4.2.
Lectins
Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.
Polyisoprenyl Phosphate Oligosaccharides
These compounds function as activated glycosyl carriers in the biosynthesis of glycoproteins and glycophospholipids. Include the pyrophosphates.
Polyisoprenyl Phosphate Monosaccharides
These compounds function as activated monosaccharide carriers in the biosynthesis of glycoproteins and oligosaccharide phospholipids. Obtained from a nucleoside diphosphate sugar and a polyisoprenyl phosphate.
Golgi Apparatus
A stack of flattened vesicles that functions in posttranslational processing and sorting of proteins, receiving them from the rough ENDOPLASMIC RETICULUM and directing them to secretory vesicles, LYSOSOMES, or the CELL MEMBRANE. The movement of proteins takes place by transfer vesicles that bud off from the rough endoplasmic reticulum or Golgi apparatus and fuse with the Golgi, lysosomes or cell membrane. (From Glick, Glossary of Biochemistry and Molecular Biology, 1990)
Polyisoprenyl Phosphate Sugars
Compounds functioning as activated glycosyl carriers in the biosynthesis of glycoproteins and glycophospholipids. They include the polyisoprenyl pyrophosphates.
Fucose
Fucose is a deoxyhexose sugar, specifically a L-configuration 6-deoxygalactose, often found as a component of complex carbohydrates called glycans in various glycoproteins and glycolipids within the human body.
Dolichol Monophosphate Mannose
A lipophilic glycosyl carrier of the monosaccharide mannose in the biosynthesis of oligosaccharide phospholipids and glycoproteins.
Mass Spectrometry
Mutation
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.
Glycoside Hydrolases
Glycoside Hydrolases are a class of enzymes that catalyze the hydrolysis of glycosidic bonds, resulting in the breakdown of complex carbohydrates and oligosaccharides into simpler sugars.
Swainsonine
An indolizidine alkaloid from the plant Swainsona canescens that is a potent alpha-mannosidase inhibitor. Swainsonine also exhibits antimetastatic, antiproliferative, and immunomodulatory activity.
Transferases (Other Substituted Phosphate Groups)
Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase
A group of related enzymes responsible for the endohydrolysis of the di-N-acetylchitobiosyl unit in high-mannose-content glycopeptides and GLYCOPROTEINS.
Uridine Diphosphate Galactose
A nucleoside diphosphate sugar which can be epimerized into UDPglucose for entry into the mainstream of carbohydrate metabolism. Serves as a source of galactose in the synthesis of lipopolysaccharides, cerebrosides, and lactose.
Electrophoresis, Polyacrylamide Gel
N-Acetylgalactosaminyltransferases
Neisseria
Mannosidases
Glycoside hydrolases that catalyze the hydrolysis of alpha or beta linked MANNOSE.
Cricetinae
A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.
N-Acetylneuraminic Acid
An N-acyl derivative of neuraminic acid. N-acetylneuraminic acid occurs in many polysaccharides, glycoproteins, and glycolipids in animals and bacteria. (From Dorland, 28th ed, p1518)
Brefeldin A
Carbohydrate Metabolism
Cellular processes in biosynthesis (anabolism) and degradation (catabolism) of CARBOHYDRATES.
Indolizines
Carbohydrates
The largest class of organic compounds, including STARCH; GLYCOGEN; CELLULOSE; POLYSACCHARIDES; and simple MONOSACCHARIDES. Carbohydrates are composed of carbon, hydrogen, and oxygen in a ratio of Cn(H2O)n.
Hygromycin B
Nucleoside Diphosphate Sugars
Concanavalin A
Saccharomyces cerevisiae
Viral Envelope Proteins
Layers of protein which surround the capsid in animal viruses with tubular nucleocapsids. The envelope consists of an inner layer of lipids and virus specified proteins also called membrane or matrix proteins. The outer layer consists of one or more types of morphological subunits called peplomers which project from the viral envelope; this layer always consists of glycoproteins.
Wheat Germ Agglutinins
Lectins purified from the germinating seeds of common wheat (Triticum vulgare); these bind to certain carbohydrate moieties on cell surface glycoproteins and are used to identify certain cell populations and inhibit or promote some immunological or physiological activities. There are at least two isoforms of this lectin.
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.
Cell Membrane
Base Sequence
Mucins
High molecular weight mucoproteins that protect the surface of EPITHELIAL CELLS by providing a barrier to particulate matter and microorganisms. Membrane-anchored mucins may have additional roles concerned with protein interactions at the cell surface.
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.
Cells, Cultured
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)
1-Deoxynojirimycin
Galactose
An aldohexose that occurs naturally in the D-form in lactose, cerebrosides, gangliosides, and mucoproteins. Deficiency of galactosyl-1-phosphate uridyltransferase (GALACTOSE-1-PHOSPHATE URIDYL-TRANSFERASE DEFICIENCY DISEASE) causes an error in galactose metabolism called GALACTOSEMIA, resulting in elevations of galactose in the blood.
Protein Array Analysis
Genetic Complementation Test
Intracellular Membranes
Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.
Mannans
Polysaccharides consisting of mannose units.
Endoplasmic Reticulum Stress
Various physiological or molecular disturbances that impair ENDOPLASMIC RETICULUM function. It triggers many responses, including UNFOLDED PROTEIN RESPONSE, which may lead to APOPTOSIS; and AUTOPHAGY.
Monensin
An antiprotozoal agent produced by Streptomyces cinnamonensis. It exerts its effect during the development of first-generation trophozoites into first-generation schizonts within the intestinal epithelial cells. It does not interfere with hosts' development of acquired immunity to the majority of coccidial species. Monensin is a sodium and proton selective ionophore and is widely used as such in biochemical studies.
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.
Microsomes
Artifactual vesicles formed from the endoplasmic reticulum when cells are disrupted. They are isolated by differential centrifugation and are composed of three structural features: rough vesicles, smooth vesicles, and ribosomes. Numerous enzyme activities are associated with the microsomal fraction. (Glick, Glossary of Biochemistry and Molecular Biology, 1990; from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
Hexosaminidases
Enzymes that catalyze the hydrolysis of N-acylhexosamine residues in N-acylhexosamides. Hexosaminidases also act on GLUCOSIDES; GALACTOSIDES; and several OLIGOSACCHARIDES.
Cell Wall
The outermost layer of a cell in most PLANTS; BACTERIA; FUNGI; and ALGAE. The cell wall is usually a rigid structure that lies external to the CELL MEMBRANE, and provides a protective barrier against physical or chemical agents.
Chromatography, High Pressure Liquid
Cloning, Molecular
Acetylglucosaminidase
A beta-N-Acetylhexosaminidase that catalyzes the hydrolysis of terminal, non-reducing 2-acetamido-2-deoxy-beta-glucose residues in chitobiose and higher analogs as well as in glycoproteins. Has been used widely in structural studies on bacterial cell walls and in the study of diseases such as MUCOLIPIDOSIS and various inflammatory disorders of muscle and connective tissue.
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.
Glucose
West Nile virus
A species of FLAVIVIRUS, one of the Japanese encephalitis virus group (ENCEPHALITIS VIRUSES, JAPANESE). It can infect birds and mammals. In humans, it is seen most frequently in Africa, Asia, and Europe presenting as a silent infection or undifferentiated fever (WEST NILE FEVER). The virus appeared in North America for the first time in 1999. It is transmitted mainly by CULEX spp mosquitoes which feed primarily on birds, but it can also be carried by the Asian Tiger mosquito, AEDES albopictus, which feeds mainly on mammals.
Fibroblasts
Cattle
Mutagenesis, Site-Directed
CHO Cells
CELL LINE derived from the ovary of the Chinese hamster, Cricetulus griseus (CRICETULUS). The species is a favorite for cytogenetic studies because of its small chromosome number. The cell line has provided model systems for the study of genetic alterations in cultured mammalian cells.
Protein Precursors
Protein precursors, also known as proproteins or prohormones, are inactive forms of proteins that undergo post-translational modification, such as cleavage, to produce the active functional protein or peptide hormone.
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.
Transfection
Deoxy Sugars
'Deoxy sugars' are monosaccharides or oligosaccharides that contain fewer hydroxyl groups than the corresponding hexose or pentose, with deoxyribose being a well-known example of a deoxy sugar.
Saccharomyces cerevisiae Proteins
Proteins obtained from the species SACCHAROMYCES CEREVISIAE. The function of specific proteins from this organism are the subject of intense scientific interest and have been used to derive basic understanding of the functioning similar proteins in higher eukaryotes.
Transcription Factor CHOP
A CCAAT-enhancer binding protein that is induced by DNA DAMAGE and growth arrest. It serves as a dominant negative inhibitor of other CCAAT-enhancer binding proteins.
Thapsigargin
Unfolded Protein Response
A cellular response to environmental insults that cause disruptions in PROTEIN FOLDING and/or accumulation of defectively folded protein in the ENDOPLASMIC RETICULUM. It consists of a group of regulatory cascades that are triggered as a response to altered levels of calcium and/or the redox state of the endoplasmic reticulum. Persistent activation of the unfolded protein response leads to the induction of APOPTOSIS.
Sulfur Radioisotopes
Neuraminidase
An enzyme that catalyzes the hydrolysis of alpha-2,3, alpha-2,6-, and alpha-2,8-glycosidic linkages (at a decreasing rate, respectively) of terminal sialic residues in oligosaccharides, glycoproteins, glycolipids, colominic acid, and synthetic substrate. (From Enzyme Nomenclature, 1992)
Virulence
The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.
Carbon Radioisotopes
Models, Biological
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.
Dystroglycans
Dystrophin-associated proteins that play role in the formation of a transmembrane link between laminin-2 and DYSTROPHIN. Both the alpha and the beta subtypes of dystroglycan originate via POST-TRANSLATIONAL PROTEIN PROCESSING of a single precursor protein.
Magnetic Resonance Spectroscopy
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.
Sialic Acids
Uridine Diphosphate Sugars
Uridine Diphosphate (UDP) sugars are nucleotide sugars that serve as essential glycosyl donors in the biosynthesis of various glycoconjugates, including proteoglycans and glycoproteins.
Molecular Chaperones
A family of cellular proteins that mediate the correct assembly or disassembly of polypeptides and their associated ligands. Although they take part in the assembly process, molecular chaperones are not components of the final structures.
Cricetulus
Protein Biosynthesis
The biosynthesis of PEPTIDES and PROTEINS on RIBOSOMES, directed by MESSENGER RNA, via TRANSFER RNA that is charged with standard proteinogenic AMINO ACIDS.
Galactosyltransferases
Precipitin Tests
Gastric Mucins
Alkaloids
Organic nitrogenous bases. Many alkaloids of medical importance occur in the animal and vegetable kingdoms, and some have been synthesized. (Grant & Hackh's Chemical Dictionary, 5th ed)
Binding Sites
Heat-Shock Proteins
Calnexin
A lectin found in ENDOPLASMIC RETICULUM membranes that binds to specific N-linked OLIGOSACCHARIDES found on newly synthesized proteins. It may play role in PROTEIN FOLDING or retention and degradation of misfolded proteins in the endoplasmic reticulum.
Protein Transport
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.
Biological Transport
RNA, 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.
COS Cells
CELL LINES derived from the CV-1 cell line by transformation with a replication origin defective mutant of SV40 VIRUS, which codes for wild type large T antigen (ANTIGENS, POLYOMAVIRUS TRANSFORMING). They are used for transfection and cloning. (The CV-1 cell line was derived from the kidney of an adult male African green monkey (CERCOPITHECUS AETHIOPS).)
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)