| deoxyribonucleases, type II site-specific | <enzyme> Enzyme systems containing a single subunit and requiring only magnesium for endonucleolytic activity. The corresponding modification methylases are separate enzymes. The systems recognise specific short DNA sequences and cleave either within, or at a short specific distance from, the recognition sequence to give specific double-stranded fragments with terminal 5'-phosphates. Enzymes from different microorganisms with the same specificity are called isoschizomers. Registry number: EC 3.1.21.4 (12 Dec 1998) |
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| deoxyribonucleases, type I site-specific | <enzyme> Enzyme systems containing three different subunits and requiring ATP, s-adenosylmethionine, and magnesium for endonucleolytic activity to give random double-stranded fragments with terminal 5'-phosphates. They function also as DNA-dependent atpases and modification methylases, catalyzing the reactions of EC 2.1.1.72 and EC 2.1.1.73 with similar site-specificity. The systems recognise specific short DNA sequences and cleave at sites remote from the recognition sequence. Enzymes from different microorganisms with the same specificity are called isoschizomers. Registry number: EC 3.1.21.3 (12 Dec 1998) |
| IgA-specific serine endopeptidase | <enzyme> Extracellular microbial enzymes whose only substrate is human IgA of the iga1 subclass; cleave the immunoglobulin at a specific internal prolyl-threonyl peptide bond in the heavy chain to yield intact faba and fca fragments; consider also EC 3.4.24.13 Registry number: EC 3.4.21.72 Synonym: immunoglobulin a(1) protease, iga1 protease, immunoglobulin a1 protease, IgA protease (26 Jun 1999) |
| organ-specific | Denoting or pertaining to a serum produced by the injection of the cells of a certain organ or tissue that, when injected into another animal, destroys the cells of the corresponding organ. (05 Mar 2000) |
| tail-specific protease | <enzyme> Selectively degrades proteins with nonpolar c termini Registry number: EC 3.4.99.- Synonym: tsp protease, prc protein, prc gene product (26 Jun 1999) |
| tumour-specific transplantation antigens | Surface antigen's of DNA tumour virus-transformed cells, which elicit an immune rejection of the virus-free cells when transplanted into an animal that has been immunised against the specific cell-transforming virus. (05 Mar 2000) |
| uridine-specific acid nuclease | <enzyme> Chicken liver enzyme hydrolyzes poly(u) and e. Coli RNA Registry number: EC 3.1.- (26 Jun 1999) |
| fluoroacetate-specific dehalogenase | <enzyme> Acts on fluoroacetamide at 0.1 the rate for fluoroacetate Registry number: EC 3.8.1.- Synonym: fluoroacetate-specific defluorinase, fac dehalogenase (26 Jun 1999) |
| law of specific nerve energies | Each type of sensory nerve ending, however stimulated (electrically, mechanically, etc.), gives rise to its own specific sensation; moreover, each type of sensation depends not upon any special character of the different nerves but upon the part of the brain in which their fibres terminate. Synonym: law of specific nerve energies. (05 Mar 2000) |
| lymphocyte specific protein tyrosine kinase p56(lck) | <enzyme> This enzyme is a lymphoid specific src family tyrosine kinase that is critical for T-cell development and activation. Lck is associated with the cytoplasmic domains of CD4, CD8 and the beta-chain of the il-2 receptor, and is thought to be involved in the earliest steps of tcr-mediated T-cell activation. Registry number: EC 2.7.11.- (12 Dec 1998) |
| acetone-insoluble antigen | A diphosphatidyl glycerol that is found in the membrane of Treponema pallidum and is the antigen detected by the Wasserman test for syphilis. (18 Nov 1997) |
| allogeneic antigen | Genetic variations of the same antigens within a given species. (05 Mar 2000) |
| antigen | Virus coded cell surface antigens that appear soon after the infection of a cell by virus, but before virus replication has begun. See: early gene. (18 Nov 1997) |
| antigen-antibody complex | The complex formed by the binding of antigen and antibody molecules. The deposition of large antigen-antibody complexes leading to tissue damage causes immune complex diseases. If the antigen is polyvalent the complex may be insoluble. Immune complexes activate complement through the classical pathway. See: glomerulonephritis, Arthus reaction, type III hypersensitivity. (12 Dec 1998) |
| antigen-antibody reaction | The phenomenon, occurring in vitro or in vivo, of antibody combining with antigen of the type that stimulated the formation of the antibody, thereby resulting in agglutination, precipitation, complement fixation, greater susceptibility to ingestion and destruction by phagocytes, or neutralization of exotoxin. See: skin test. (05 Mar 2000) |