| heavy chain | <protein> In general, the larger polypeptide in a multimeric protein. Thus the immunoglobulin heavy chain is of 50 kD, the light chain of 22 kD, whereas in myosin the heavy chain is very much larger (220 kD) than the light chains (~20 kD). (18 Nov 1997) |
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| heavy chain disease | A disorder of immunoglobulin synthesis in which large quantities of abnormal heavy chains are excreted in the urine. The amino acid sequences of the n- (amino-) terminal regions of these chains are normal, but they have a deletion extending from part of the variable domain through the first domain of the constant region, so that they cannot form cross-links to the light chains. The defect arises through faulty coupling of the variable (v) and constant (c) region genes. (12 Dec 1998) |
| 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) |
| 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) |
| immunoglobulins, gamma-chain | Heavy chains found in the fab and fc fragments of IgG and having a molecular weight of approximately 51 kD. They contain about 450 amino acid residues arranged in four domains and an oligosaccharide component covalently bound to the fc fragment. The gamma chains of the four IgG subgroups are not identical, but resemble each other more closely than the heavy chains of a different immunoglobulin. (12 Dec 1998) |
| immunoglobulins, heavy-chain | Major components of immunoglobulin molecules. They are the larger of the two types of polypeptide chains responsible for the biological and immunological properties of the different immunoglobulins. They differ according to the class of ig from which they were isolated, contain 450 to 600 amino acid residues per chain, and have molecular weights of 51-72 kD. One ig molecule comprises two heavy and two light chains. (12 Dec 1998) |
| immunoglobulins, j-chain | The immunoglobulin fragments found in the light chain fractions of secretory IgA and polymeric IgM in a ratio of one j chain per one IgA dimer or one IgM pentamer. It is a polypeptide with a molecular weight of about 17 kD and probably serves either to bind the components of the globulins together or to transfer the globulins across membranes. (12 Dec 1998) |
| immunoglobulins, kappa-chain | One of the light chains of the immunoglobulins with a molecular weight of approximately 22 kD. They constitute about 60% of all light chains and can be recognised serologically as well as by their specific amino acid sequence. (12 Dec 1998) |