| 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) |
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| 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) |
| immunoglobulins, lambda-chain | One of the light chains of the immunoglobulins with a molecular weight of approximately 22 kD. They constitute about 40% of all light chains and can be recognised serologically as well as by their specific amino acid sequence. (12 Dec 1998) |
| immunoglobulins, light-chain | Polypeptide chains, consisting of 211 to 217 amino acid residues, isolated from immunoglobulins and having a molecular weight of approximately 22 kD. There are two major types of light chains, kappa and lambda. In man they are found in a ratio of 60% to 40%, respectively. Both chains consist of linear repeating, similar, but not identical, segments of about 110 amino acid residues. In each segment a disulfide bond establishes a tightly folded approximately 60-membered loop or domain. Adjacent domains are linked by less tightly folded regions. Both light chains contain two such domains. Two light and two heavy chains make one immunoglobulin molecule, but both light chains in one ig are of the same type. (12 Dec 1998) |
| immunoglobulins, mu-chain | Heavy chains found in the fab and fc fragments of IgM and having a molecular weight of approximately 72 kD. They contain about 57 amino acid residues arranged in five domains and have more oligosaccharide branches and a higher carbohydrate content than the heavy chains of IgG. (12 Dec 1998) |
| invariant chain | <chemical> Noncovalently associated with class II antigens, alpha and beta chain complex; involved in the regulation of malignant cell ia function; iip31 and iip33 were synthesized by using alternative initiator methionines Synonym: II igc, ia-associated invariant chain, II invariant glycoprotein complex, class II-associated invariant chain, IIp33, IIp31, clip peptide, ln-2 antigen, ln 2 antigen, cd74 antigen, II-key, II76-92 (05 Dec 1998) |
| open chain compound | An organic compound in which the chain does not form a ring. Synonym: aliphatic compound, open chain compound. (05 Mar 2000) |
| ossicular chain | The small bones of the middle ear; they are articulated to form a chain for the transmission of sound from the tympanic membrane to the oval window. Synonym: ossicula auditus, ear bones, ossicular chain. (05 Mar 2000) |
| EDTA light chain | <protein> Myosin light chains (18 kD) from scallop muscle (two per pair of heavy chains), easily extracted by calcium chelation. Although the EDTA light chains do not bind calcium they confer calcium sensitivity on the myosin heavy chains. (18 Nov 1997) |
| electron transport chain | <biochemistry, chemistry> A series of compounds that transfer electrons to an eventual donor with concomitant energy conversion. One of the best studied is in the mitochondrial inner membrane, that takes NADH (from the tricarboxylic acid cycle) or FADH and transfers electrons via ubiquinone, cytochromes and various other compounds, to oxygen. Other electron transport chains are involved in photosynthesis. (18 Nov 1997) |
| J chain | <molecular biology> A polypeptide chain (15 kD), found in IgA and in IgM joining heavy chains (H chains) to each other to form dimers of IgA and pentamers of IgM. Disulphide bonds are formed between the J chain and H chains near the Fc ends of the heavy chains. Despite the similar name, it is not identical with the J region or coded for by the J gene. Synonym: J piece. (10 Jan 1998) |
| kappa chain | <protein> Either of two types of light chains (small polypeptide chains) that are found in immunoglobulins. (09 Oct 1997) |
| 2-methyl branched-chain enoyl-CoA reductase | <enzyme> Important in the reversal of beta-oxidation under anaerobic conditions in ascaris suum Registry number: EC 1.3.1.52 Synonym: 2-methyl bce-CoA reductase (26 Jun 1999) |
| lambda chain | <immunology> Although light chains are found in many multimeric proteins, L chain usually refers to the light chains of immunoglobulins. These are of 22 kD and of one of two types, kappa or lambda. A single immunoglobulin has identical light chains (2 kappa or 2 lamda). Light chains have one variable and one constant region. There are isotype variants of both kappa and lamda. (25 Jun 1999) |
| lauric acid in-chain-hydroxylase | <enzyme> Specific for lauric acid; hydroxylates at c-8, c-9 or c-10 of chain Registry number: EC 1.14.14.- Synonym: (cytochrome p-450)-dependent laurate in-chain-hydroxylase (26 Jun 1999) |