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Definition
 
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Catalysis definition: The facilitation of a chemical reaction by material (catalyst) that is not consumed by the reaction.
Catalysis definition: Acceleration of a chemical reaction induced by the presence of material that is chemically unchanged at the end of the reaction.
RNA, Catalytic definition: RNA that has catalytic activity. The catalytic RNA sequence folds to form a complex surface that can function as an enzyme in reactions with itself and other molecules. It may function even in the absence of protein. There are numerous examples of RNA species that are acted upon by catalytic RNA, however the scope of this enzyme class is not limited to a particular type of substrate.
ribozyme definition: catalytic macromolecules, frequently autohydrolytic, composed of RNA.
Ribozyme definition: RNA that contains an intron sequence which has an enzyme-like catalytic activity. This intron sequence has been shown to fold up to form a complex surface that can function like an enzyme in reactions with other RNA molecules and thus synthesize new molecules even in the absence of protein. Synthetic ribozymes can be engineered to specifically cleave a target RNA sequence causing expression down regulation.
1-Phosphatidylinositol 4-Kinase definition: An enzyme that catalyzes the conversion of phosphatidylinositol (PHOSPHATIDYLINOSITOLS) to phosphatidylinositol 4-phosphate, the first committed step in the biosynthesis of phosphatidylinositol 4,5-bisphosphate.
Phosphoinositide-4-Kinase Catalytic Beta Polypeptide definition: Phosphoinositide-4-Kinase, Catalytic, Beta Polypeptide, encoded by the PIK4CB gene, belongs to the PI3/PI4-kinase family. This protein phosphorylates phosphatidylinositol (PI) in the first committed step in the production of the second messenger inositol-1,4,5,-trisphosphate (PIP). It may regulate Golgi disintegration/reorganization during mitosis, possibly via its phosphorylation. Its enzymatic activity is inhibited by wortmannin. This protein is found in the outer membrane of mitochondria and membranes of the rough endoplasmic reticulum, and recruited to the Golgi complex by the small GTPase ARF to stimulate the synthesis of phosphatidylinositol 4,5-biphosphate (PIP2) on the Golgi complex. Two named isoforms exist resulting from alternative splicing. (from Swiss-Prot)
Antibodies, Catalytic definition: Antibodies that can catalyze a wide variety of chemical reactions. They are characterized by high substrate specificity and share many mechanistic features with enzymes.
abzyme definition: antibodies whose binding site catalyzes a chemical reaction like the active site of an enzyme; may be genetically engineered by fusing enzyme and antibody genes, or produced by immunizing animals with transition state analogs.
active site definition: molecular location on an enzyme where substrate binds and catalysis occurs.
Active Site definition: The catalytic site of an enzyme, the part of an enzyme where the actual enzymatic function is performed.
proteasome definition: macromolecular structures present in the cytosol and nucleus in cells; have multiple protease activities.
Proteasome Endopeptidase Complex definition: A large multisubunit complex that plays an important role in the degradation of most of the cytosolic and nuclear proteins in eukaryotic cells. It contains a 700-kDa catalytic sub-complex and two 700-kDa regulatory sub-complexes. The complex digests ubiquitinated proteins and protein activated via ornithine decarboxylase antizyme.
Proteasome definition: Proteolytic complexes, proteolytic core of the proteasome system, that degrade cytosolic and nuclear proteins are implicated in ATP dependent ubiquitin protein complex degradation and in antigen processing in antigen presenting cells. The 20S proteasome (700 kD), essential in ATP ubiquitin degradation pathway, has 13-15 subunits each of which has three or four different peptidase activities. The 20S proteasome interacts with additional subunits, PA700 and PA28, to form an ATP-dependent multicatalytic proteinase complex (MPC) involved in the degradation of ubiquitinated cellular proteins and certain non-ubiquitinated proteins. 26S proteasomes may be formed in an ATP dependent fashion from a 20S proteasome and additional components, CF1 (660 kD), CF2 (250 kD) and CF3 (600 kD).
20S Proteasome definition: The 20S proteasome, as proteolytic core of the proteasome system, is essential in ATP dependent ubiquitin protein complex degradation and in antigen processing in antigen presenting cell. It has 13-15 subunits each of which has three or four different peptidase activities. 26S proteasomes may be formed in an ATP dependent fashion from a 20S proteasome and additional components, CF1 (660 kD), CF2 (250 kD) and CF3 (600 kD). The 20S proteasome interacts with additional subunits, PA700 and PA28, to form an ATP-dependent multicatalytic proteinase complex (MPC) involved in the ATP ubiquitin degradation pathway.
enzyme activity definition: the rate of catalysis by enzymes.
catalytic activity definition: Catalysis of a biochemical reaction at physiological temperatures. In biologically catalyzed reactions, the reactants are known as substrates, and the catalysts are naturally occurring macromolecular substances known as enzymes. Enzymes possess specific binding sites for substrates, and are usually composed wholly or largely of protein, but RNA that has catalytic activity (ribozyme) is often also regarded as enzymatic. [ISBN:0198506732 "Oxford Dictionary of Biochemistry and Molecular Biology"]
Phosphoinositide-3-Kinase Catalytic Gamma Polypeptide definition: Phosphoinositide-3-Kinase, Catalytic, Gamma Polypeptide, encoded by the PIK3CG gene, belongs to the PI3/PI4-kinase family of proteins. This protein is an enzyme that phosphorylates phosphoinositides on the 3-hydroxyl group of the inositol ring. It is an important modulator of extracellular signals, including those elicited by E-cadherin-mediated cell-cell adhesion, which plays an important role in maintenance of the structural and functional integrity of epithelia. In addition to its role in promoting assembly of adherens junctions, the protein is thought to play a pivotal role in the regulation of cytotoxicity in NK cells. (from LocusLink)
CATALYTIC METHODS, AMYLASE definition: An amylase test system is a device intended to measure the activity of the enzyme amylase in serum and urine. Amylase measurements are used primarily for the diagnosis and treatment of pancreatitis (inflammation of the pancreas).
DNA, Catalytic definition: Molecules of DNA that possess enzymatic activity.
Catalytic Domain definition: The region of an enzyme that interacts with its substrate to cause the enzymatic reaction.
Decontaminants, Chemical Neutralization, Catalytic Enzyme definition: Chemical-neutralization decontamination products consisting of a mixture of catalytic enzymes such as organophosphorous hydrolase or organophosphorous acid anhydrolase and other natural products. The catalytic property of the enzymes allow them to decontaminate many times their own weight of agent in a short time (either seconds or a few minutes). Enzymes with different properties and specificities can be mixed together in a single formulation, making them very effective against a variety of chemical agents (e.g., G-type and/or VX nerve agents, sulfur mustard) and also against biological agents (e.g., bacterial cells, anthrax spores).
regulation of catalytic activity definition: Any process that modulates the activity of an enzyme. [GOC:ai]
negative regulation of catalytic activity definition: Any process that stops or reduces the activity of an enzyme. [GOC:jl, GOC:tb]
positive regulation of catalytic activity definition: Any process that activates or increases the activity of an enzyme. [GOC:jl, GOC:tb]
Casein Kinase 2, Alpha 1 Polypeptide definition: Casein Kinase 2, Alpha 1 Polypeptide is encoded by the CSNK2A1 gene. Casein kinase II is a serine/threonine protein kinase that phosphorylates acidic proteins such as casein. This kinase exists as a tetramer and is composed of an alpha, an alpha-prime, and two beta subunits. The alpha subunits contain the catalytic activity while the beta subunits undergo autophosphorylation. Three transcript variants encoding two different isoforms have been found for this gene. (From LocusLink)
PIK3CA Gene definition: This gene is involved in apoptosis, cell growth and angiogenesis.
PIK3CB Gene definition: This gene is involved in apoptosis, cell growth and angiogenesis.
PIK3CG Gene definition: This gene is involved in cell adhesion, signal transduction and maintenance of the structural and functional integrity of epithelia.
PIK4CB Gene definition: This gene is involved in signal transduction and cell organization/biogenesis.
Phosphoinositide-3-Kinase Catalytic Beta Polypeptide definition: Phosphoinositide-3-Kinase, Catalytic, Beta Polypeptide, encoded by the PIK3CB gene, belongs to the PI3/PI4-kinase family. Phosphatidylinositol 3 Kinase is a heterodimer of a P110 (catalytic) and a P85 (regulatory) subunit. It phosphorylates PTDINS, PTDINS4P and PTDINS(4,5)P2 with a preference for PTDINS(4,5)P2. (from Swiss-Prot)
Phosphoinositide-3-Kinase Catalytic Alpha Polypeptide definition: Phosphoinositide-3-Kinase, Catalytic, Alpha Polypeptide, encoded by the PIK3CA gene, belongs to the PI3/PI4-kinase family. Phosphatidylinositol 3 Kinase is a heterodimer of a P110 (catalytic) and a P85 (regulatory) subunit. It phosphorylates PTDINS, PTDINS4P and PTDINS(4,5)P2 with a preference for PTDINS(4,5)P2. (from Swiss-Prot)
Calcineurin A Alpha definition: Encoded by human PPP3CA Gene (PPP Phosphatase/PP-2B Family), 521-aa 59-kDa Calcineurin A Alpha is a calmodulin-binding catalytic subunit of ubiquitous heterodimeric Ca(2+)/calmodulin-regulated protein phosphatase Calcineurin involved in many biologic activities as a modifier of phosphorylation status. Calcineurin catalytic subunits are derived from alternatively spliced highly conserved PPP3CA, PPP3CB, PPP3CC genes. IGF1 stimulates a myocyte switch to glycolytic metabolism by activating calcineurin A, inducing nuclear translocation of NFATC1 transcription factor, and association of calcineurin, GATA2, and dephosphorylated NFATC1. DSCR1 interacts with calcineurin A in the linker region between the catalytic domain and the calcineurin B-binding domain. DSCR1 and ZAKI4 may inhibit calcineurin-dependent gene transcription through inhibition of NFAT translocation to the nucleus. (NCI)
Calcineurin A Beta definition: Encoded by human PPP3CB Gene (PPP Phosphatase/PP-2B Family), 510-aa Calcineurin A Beta is a brain calmodulin-binding catalytic subunit of ubiquitous heterodimeric Ca(2+)/calmodulin-regulated protein phosphatase Calcineurin. Calcineurin catalytic subunits are derived from alternatively spliced highly conserved PPP3CA, PPP3CB, PPP3CC genes. Activated PPP3CB appears involved in dopaminergic signal transduction and in some glutamatergic NMDA receptor-dependent synaptic plasticity. (NCI)
Calcineurin A Gamma definition: Encoded by human PPP3CC Gene (PPP Phosphatase/PP-2B Family), 502-aa 57-kDa Calcineurin A Gamma is a testicular calmodulin-binding catalytic subunit of ubiquitous heterodimeric Ca(2+)/calmodulin-regulated protein phosphatase Calcineurin involved in many biologic activities as a modifier of phosphorylation status. Calcineurin catalytic subunits are derived from alternatively spliced highly conserved PPP3CA, PPP3CB, PPP3CC genes. PPP3CC may be associated with the flagellum and regulate sperm motility. (NCI)
Cyclic AMP-Dependent Protein Kinase Catalytic Subunits definition: Specific enzyme subunits that form the active sites of the type I and type II cyclic-AMP protein kinases. Each molecule of enzyme contains two catalytic subunits.
protein kinase A catalytic subunit binding definition: Interacting selectively with one or both of the catalytic subunits of protein kinase A. [GOC:mah]
 
 
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katalytisch definition: [1] mit Hilfe einer Katalyse oder die Katalsye betreffend