| heat-shock protein | <cell biology, molecular biology, protein> Families of proteins conserved through prokaryotic and eukaryotic cells and bacteria in response to hyperthermia and other environmental stresses, although some are constitutively expressed. They increase thermal tolerance and perform functions essential to cell survival under these conditions. Some serve to stabilise proteins in abnormal configurations, play a role in folding and unfolding of proteins and the assembly of oligomeric complexes and may act as chaperonins. Hsp90 complexes with inactive steroid hormone receptor and is displaced upon ligand binding. Four major sub classes are recognised: hsp90, hsp70, hsp60 and small hsps. Hsps have been suggested to act as major immunogens in many infections. Acronym: HSP (12 Dec 1998) |
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| heat-shock protein 27 kinase | <enzyme> Phosphorylates hsp 26 on serine residues when stimulated by tumour necrosis factor or interleukin 1 Registry number: EC 2.7.1.- Synonym: hsp 27 kinase, heat-shock protein 27 kinase, hsp27 kinase (26 Jun 1999) |
| helix destabilising protein | <molecular biology, protein> Proteins involved in DNA replication. They bind cooperatively to single stranded areas of a DNA molecule in a double helix, causing the helix to unwind and preventing the reformation of the duplex and extending the DNA backbone, thus making the exposed bases more accessible for base pairing. (10 Oct 1997) |
| protective protein | An immunoglobulin molecule that has a specific amino acid sequence by virtue of which it interacts only with the antigen that induced its synthesis in cells of the lymphoid series (especially plasma cells) or with antigen closely related to it. Antibodies are classified according to their ode of action as agglutinins, bacteriolysins, haemolysins, opsonins, precipitins, etc. (18 Nov 1997) |
| protein | <biochemistry> Any of a group of complex organic compounds which contain carbon, hydrogen, oxygen, nitrogen and usually sulphur, the characteristic element being nitrogen and which are widely distributed in plants and animals. Proteins, the principal constituents of the protoplasm of all cells, are of high molecular weight and consist essentially of combinations of a amino acids in peptide linkages. Twenty different amino acids are commonly found in proteins and each protein has a unique, genetically defined amino acid sequence which determines its specific shape and function. They serve as enzymes, structural elements, hormones, immunoglobulins, etc. And are involved in oxygen transport, muscle contraction, electron transport and other activities throughout the body and in photosynthesis. Origin: Gr. Protos = first (18 Nov 1997) |
| protein 4.1 | A peripheral protein that binds tightly to spectrin in the red cell membrane; it also binds to certain glycophorins and helps determine the shape and flexibility of the red blood cell. (05 Mar 2000) |
| SCH9 protein kinase | <enzyme> Acts independently of camp-dependent protein kinase and the transcriptional activator adr1 in controlling yeast adh2 expression Registry number: EC 2.7.1.- (26 Jun 1999) |
| protein A | Protein obtained from Staphylococcus aureus that binds immunoglobulin molecules without interfering with their binding to antigen. Widely used in purification of immunoglobulins and in antigen detection, for example by immunoprecipitation. A very effective B-cell mitogen. (18 Nov 1997) |
| protein A24 lyase | <enzyme> Releases histone 2a and ubiquitin from chromosomal protein a24 Registry number: EC 4.- (26 Jun 1999) |
| protein activator, aminolevulinic acid synthetase | <chemical> From rat liver mitochondria Synonym: aminolevulinic acid synthetase activator (26 Jun 1999) |
| protein acyl kinase | <enzyme> Transfers gamma-phosphate of ATP to a protein acceptor with formation of an acyl phosphate bond Registry number: EC 2.7.2.- (26 Jun 1999) |
| protein acyltransferase | <enzyme> Human placental enzyme active in posttranslational acylation of membrane glycoproteins Registry number: EC 2.3.1.- Synonym: glycoprotein palmitoyltransferase (26 Jun 1999) |
| protein-arginine n-methyltransferase | <enzyme> An enzyme that catalyses the methylation of arginine residues of proteins to yield n-mono- and n,n-dimethylarginine. This enzyme is found in many organs, primarily brain and spleen. Chemical name: S-Adenosyl-L-methionine:protein-L-arginine N-methyltransferase Registry number: EC 2.1.1.23 (12 Dec 1998) |
| 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. (12 Dec 1998) |
| protein-bound iodine | Thyroid hormone in its circulating form, consisting of one or more of the iodothyronines bound to one or more of the serum proteins. (05 Mar 2000) |