lanosterol
| 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) |
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| 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) |
| 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) |
| 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) |