| fimbriae, bacterial | Thin, hairlike appendages, 1 to 20 microns in length and often occurring in large numbers, present on the cells of gram-negative bacteria, particularly enterobacteriaceae and neisseria. Unlike flagella, they do not possess motility, but being protein (pilin) in nature, they possess antigenic and haemagglutinating properties. They are of medical importance because some fimbriae mediate the attachment of bacteria to cells via adhesins (adhesins, bacterial). Bacterial fimbriae refer to common pili, to be distinguished from the preferred use of "pili", which is confined to sex pili (pili, sex). (12 Dec 1998) |
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| luminescence, bacterial | The emission of light by bacteria. It is applied to studies on bacterial viability, metabolism, genetics, adhesiveness, and other physiological properties. (12 Dec 1998) |
| T-cell-rich, B-cell lymphoma | <tumour> A B-cell lymphoma in which more than 90% of the cells are of T-cell origin, masking the large cells that form the neoplastic B-cell component. See: adult T-cell lymphoma. (05 Mar 2000) |
| acetoacetyl-acyl carrier protein synthase | <enzyme> E coli enzyme, that catalyses condensation of malonyl-acyl carrier protein plus acetyl-acyl carrier protein; not inhibited by cerulenin Registry number: EC 2.3.1.- Synonym: acetoacetyl-acp synthase (26 Jun 1999) |
| acid soluble spore protein | <molecular biology> A DNA binding protein in the spores of some bacteria, thought to stabilise the DNA in an A configuration, so protecting it from cleavage by enzymes or UV light. (18 Nov 1997) |
| acute-phase protein | <haematology> These plasma proteins (in addition to fibrinogen) increase 25% or more in response to inflammation and injury are under direct control of interleukin-6 (IL-6) (hepatocyte-stimulating factor). Other proteins which increase are ceruloplasmin, C3 and C4 which increase 50% or more; alpha-1 acid glycoprotein, alpha-1 antitrypsin, haptoglobin and fibrinogen (the major determinant of viscosity 1 ) which increase two- to fourfold; C-reactive protein (CRP) and serum amyloid A which increase several hundred-fold. Despite long-held clinical opinion to the contrary, available data indicate that neither ESR nor measurement of specific acute-phase reactants are useful in excluding underlying infection or inflammation regardless of the pretest probability. These proteins are secreted into the blood in increased or decreased quantities by hepatocytes in response to trauma, inflammation, or disease. They can serve as inhibitors or mediators of the inflammatory processes. Certain acute-phase proteins have been used to diagnose and follow the course of diseases or as tumour markers. See also: amyloid, c-reactive protein, erythrocyte sedimentation rate, viscosity. (25 Jun 1999) |
| acyl-(acyl-carrier-protein)-phospholipid acyltransferase | <enzyme> Catalyses the formation of phosphatidylethanolamine from acyl-acyl carrier protein and 2-acyl-sn-glycero-3-phosphoethanolamine Registry number: EC 2.3.1.40 Synonym: 2-acyl-gpe acyltransferase, 2-acylglycerophosphoethanolamine acyltransferase (26 Jun 1999) |
| acyl-(acyl-carrier-protein)-UDP-N-acetylglucosamine acyltransferase | <enzyme> E coli enzyme involved in lipid a biosynthesis; uses beta-hydroxymyristoyl-acyl carrier protein to form udp-3-monoacyl-n-acetylglucosamine; amino acid sequence given in second source Registry number: EC 2.3.1.129 Synonym: udp-aguatransferase, lpxa protein, udp-n-acetylglucosamine-3-acyltransferase, udp-n-acetylglucosamine 3-o-acyltransferase, udp-3-o-(r-3-hydroxymyristoyl)glucosamine-n-acyltransferase, lpxd protein, fira gene product, fira protein (26 Jun 1999) |
| acyl carrier protein | <protein> A small (77 peptides long) protein which binds six other enzymes involved in fatty acid synthesis. It was first isolated in E. Coli bacteria. (09 Oct 1997) |
| acyl carrier protein acylase | <enzyme> From E coli Registry number: EC 2.3.1.- Synonym: acp acylase (26 Jun 1999) |
| acyl protein synthetase | <enzyme> Component of the fatty acid reductase complex of luminescent bacteria Registry number: EC 2.3.1.- Synonym: luxe gene product, fatty acyl-protein synthetase (26 Jun 1999) |
| AKT1 protein kinase | <enzyme> Human homolog of v-akt oncogene product Registry number: EC 2.7.10.- Synonym: akt1 protein, human (26 Jun 1999) |
| AMP-activated protein kinase kinase | <enzyme> An endogenous kinase kinase; reactivates the inactive form of AMP-activated protein kinase (AMP-pk); phosphorylates the 63-kD subunit of AMP-pk Registry number: EC 2.7.1.- Synonym: AMP-pk reactivator, hmg CoA reductase kinase kinase (26 Jun 1999) |
| amyloid beta-protein | A 4 kD protein, 39-43 amino acids long, expressed by a gene located on chromosome 21. It is the major protein subunit of the vascular and plaque amyloid filaments in individuals with alzheimer's disease and in aged individuals with trisomy 21 (down syndrome). The protein is found predominantly in the nervous system, but there have been reports of its presence in non-neural tissue. (12 Dec 1998) |
| 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) |