| amyloid beta-protein precursor | A precursor to the amyloid-beta protein (beta/a4). Alterations in the expression of the amyloid beta-protein precursor (abpp) gene, located on chromosome 21, plays a role in the development of the neuropathology common to both alzheimer disease and down syndrome. Abpp is associated with the extensive extracellular matrix secreted by neuronal cells. Upon cleavage, this precursor produces three proteins of varying amino acid lengths: 695, 751, and 770. The beta/a4 (695 amino acids) or beta-amyloid protein is the principal component of the extracellular amyloid in senile plaques found in alzheimer disease, down syndrome and, to a limited extent, in normal aging. (12 Dec 1998) |
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| amyloid precursor protein | <protein> Individuals with Alzheimer's disease are characterised by extensive accumulation of amyloid in the brain, referred to as senile plaques. These consist of a core of amyloid fibrils surrounded by dystrophic neurites. The principal component of the amyloid fibrils is B/A4, a peptide derived from the larger APP. The specific role of amyloid protein is unclear but it is thought that amyloid deposits may cause neurons to degenerate. Amyloid deposits also occur in brains of older Down's Syndrome patients. (04 May 1997) |
| amyloid protein | Glycoprotein deposited extracellularly in tissues in amyloidosis. The glycoprotein may either derive from light chain of immunoglobulin (AIO (amyloid of immune origin): 5-18 kD glycoprotein, product of a single clone of plasma cells, the N terminal part of lambda or kappa light chain) or, in what used to be referred to as AUO, amyloid of unknown origin, from serum amyloid A (SAA), one of the acute phase proteins that increases many fold in inflammation. The polypeptides are organised as a _ pleated sheet making the material rather inert and insoluble. Minor protein components are also found. Should be distinguished from _ amyloid deposited in the brain and that is derived from amyloid precursor protein (see amyloidogenic glycoprotein. (18 Nov 1997) |
| amyloid protein aa | A nonimmunoglobulin amyloid isolated from amyloid fibrils deposited in amyloidosis secondary to chronic inflammatory diseases such as rheumatoid arthritis. Antisera to amyloid protein aa have been used to detect a related serum protein saa. (12 Dec 1998) |
| amyloid protein saa | A serum protein believed to be a circulating precursor to amyloid protein aa. It is present in low concentrations in normal sera, but found in much higher concentrations in sera of older persons and in patients with amyloidosis or with diseases known to predispose to amyloidosis. Very high levels of this protein have been reported during acute inflammatory episodes. Antisera to amyloid protein aa cross-react with protein saa. (12 Dec 1998) |
| androgen binding protein | A protein secreted by testicular Sertoli cells along with inhibin and mullerian inhibiting substance. Androgen binding protein probably maintains a high concentration of androgen in the seminiferous tubules. (05 Mar 2000) |
| animal protein factor | <biochemistry> Member of the water soluble B vitamin group, important in the proper function of the nervous system and important in proper carbohydrate, protein and fat metabolism. (27 Sep 1997) |
| antifreeze protein | <protein> This is a protein found in the extracellular fluid of some fish that livein very cold water, it inhibits the formation of ice crystals. (09 Oct 1997) |
| antitermination protein | A protein that permits RNA polymerase to transcribe through certain termination sites. (05 Mar 2000) |
| antitumour protein | A protein that inhibits tumour growth. (05 Mar 2000) |
| antiviral protein | A human or animal factor, induced by interferon in virus-infected cells, which mediates interferon inhibition of virus replication. (05 Mar 2000) |
| a-protein | <protein> A protein found in the cell wall of the bacterium Staphylococcus aureus which binds to the Fc section of immunoglobulins and is therefore used to collect antigen-antibody complexes. (09 Oct 1997) |
| autologous protein | Any protein found normally in the fluids or tissues of the body. (05 Mar 2000) |
| autophosphorylation-dependent multifunctional protein kinase | <enzyme> A camp/ca(2+)-independent protein kinase; phosphorylates and activates phosphorylase b kinase; phosphorylates and inactivates glycogen synthase Registry number: EC 2.7.1.- Synonym: auto-kinase (26 Jun 1999) |
| band 3 protein | A ubiquitous membrane transport protein found in the plasma membrane of diverse cell types and tissues, and in nuclear, mitochondrial, and golgi membranes. It is the major integral transmembrane protein of the erythrocyte membrane, comprising 25% of the total membrane protein and occurring at 1 million copies per cell. It exists as a dimer and provides a channel for the transport of anions across the membrane. (12 Dec 1998) |