| kappa | a light chain of human immunoglobulins [chain] |
|---|---|
| LC | Laennec cirrhosis; Langerhans cell; late clamped; large chromophobe; lecithin cholesterol acyltransf... |
| VL | variable domain of the light chain; variable light chain |
| MLCK | myosin light chain kinase |
| PKCSL | protein kinase C light chain |
| polymerase chain reaction | <molecular biology, technique> The first practical system for in vitro amplification of DNA and as such one of the most important recent developments in molecular biology. Two synthetic oligonucleotide primers, which are complementary to two regions of the target DNA (one for each strand) to be amplified, are added to the target DNA (that need not be pure), in the presence of excess deoxynucleotides and Taq polymerase, a heat stable DNA polymerase. In a series (typically 30) of temperature cycles, the target DNA is repeatedly denatured (around 90_C), annealed to the primers (typically at 50-60_C) and a daughter strand extended from the primers (72_C). As the daughter strands themselves act as templates for subsequent cycles, DNA fragments matching both primers are amplified exponentially, rather than linearly. The original DNA need thus be neither pure nor abundant and the polymerase chain reaction has accordingly become widely used not only in research, but in clinical diagnostics and forensic science. Acronym: PCR (14 Oct 1997) |
|---|---|
| myosin light chain | <protein> The light chains of the muscle protein myosin. Each molecule of myosin is composed of two heavy chains and two pairs of light chains. The light chains have a molecular weight of about 20 kD and there is one dissimilar pair of light chains associated with each heavy chain. The proteins all have sequence homology to calmodulin, but not all with calcium binding activity. Several types are known: regulatory light chains (LC 2, DNTB light chains) probably regulate the ATPase activity of the heavy chain directly (through the binding of calcium) or indirectly (activating when they themselves are phosphorylated by myosin light chain kinase) and essential light chains (LC 1, LC 3, alkali light chains), which have a more subtle and apparently nonessential role. In molluscan muscle the EDTA light chains (similar to LC 2 from vertebrate muscle) confer calcium sensitivity on the myosin itself. The light chains are "calmodulin-like" proteins that bind calcium. Two of them can be removed easily, and two with difficulty. The light chains bind the heavy chains in the vicinity of the head groups of the myosin. (12 Dec 1998) |
| haemolytic chain | The haemolysis that occurs when complement is activated by the previously formed union of erythrocytes and specific antibody. (05 Mar 2000) |
| H chain | <protein> Heavy chain of immunoglobulin, see IgG, IgM, etc. (18 Nov 1997) |
| xenobiotic medium chain fatty acid - coenzyme A ligase | <enzyme> Partial amino acid sequence of enzyme from bovine liver mitochondria given I first source; has high sequence homology to human and rat sa protein Registry number: EC 6.2.1.- Synonym: xl-i ligase, xl-i carboxylic acid - CoA ligase (26 Jun 1999) |
| short chain | In bacteriology, a string of two to eight cells. (05 Mar 2000) |
| short-chain acyl-CoA dehydrogenase | See: acyl-CoA dehydrogenase (NADPH+). (05 Mar 2000) |
| short-chain beta-hydroxyacyl-CoA dehydrase | <enzyme> Forms trans-2-enoyl-CoA; maximal activity with trans-2-hexenoyl-CoA, followed by crotonyl-CoA; not the same as EC 4.2.1.17 Registry number: EC 4.2.1.- Synonym: beta-hydroxybutyryl-CoA dehydrase, short-chain beta-hydroxyacyl-coenzyme a dehydrase (26 Jun 1999) |
| side chain | A chain of noncyclic atoms linked to a benzene ring, or to any cyclic chain compound, the atoms of an alpha-amino acid other than the alpha-carboxyl group, the alpha-amino group, the alpha-carbon, and the hydrogen attached to the alpha-carbon. (05 Mar 2000) |
| side-chain theory | Ehrlich postulated that cells contained surface extensions or side chains (haptophores) that bind to the antigenic determinants of a toxin (toxophores); after a cell is stimulated, the haptophores are released into the circulation and become the antibodies. See: receptor. Synonym: Ehrlich's postulate. (05 Mar 2000) |
| nuclear chain fibre | The shortest and most numerous type of intrafusal muscle fibre's in a neuromuscular spindle, containing a single row of centrally positioned nuclei. (05 Mar 2000) |
| delta chain | See: immunoglobulin. The heavy chains of mouse and human IgD immunoglobulins. (18 Nov 1997) |
| immunoglobulins, alpha-chain | Heavy chains found in the fab and fc fragments of IgA and having a molecular weight of approximately 58 kD. They contain about 470 amino acid residues arranged in four domains and an oligosaccharide component bound covalently to the fc fragment. (12 Dec 1998) |
| immunoglobulins, delta-chain | Heavy chains found in the fab and fc fragments of IgD and having a molecular weight of approximately 64 kD. They contain about 500 amino acid residues arranged in four domains and an oligosaccharide component covalently bound to the fc fragment. (12 Dec 1998) |
| immunoglobulins, epsilon-chain | Heavy chains found in the fab and fc fragments of IgE and having a molecular weight of approximately 72 kD. They contain about 550 amino acid residues arranged in five domains and about three times more carbohydrate than the heavy chains of IgA, IgD, and IgG. (12 Dec 1998) |