| 释义 |
peptide Biochem.|ˈpɛptaɪd|
[ad. G. peptid, back-formation from di-, tripeptid, etc. (E. Fischer 1902, in Chemiker-Zeitung XXVI. 940/2), polypeptid (E. Fischer 1903): see polypeptide.]
1. Any compound in which two or more amino-acids are linked together by peptide bonds (see sense 2 below); according to the number of amino-acid residues such compounds are dipeptides, tripeptides, etc., oligopeptides, or polypeptides. Also attrib. or as adj.
1906Jrnl. Chem. Soc. XC. ii. 293 (heading) The fate of certain amino-acids and peptides in the organism of the dog. 1927Haldane & Huxley Animal Biol. iv. 107 We can make..a sugar or peptide (part of a protein molecule) which only differs from the natural variety in that its molecules are related to the natural molecules as a left hand to a right. 1949Abraham & Florey in H. W. Florey et al. Antibiotics I. vii. 331 The tomato-wilting agent produced by Fusarium lycopersici Sacc. was isolated by Plattner and Clauson-Kaas.., who later..showed that it was a peptide and named it lyco-marasmine. 1953Fruton & Simmonds Gen. Biochem. v. 135 Various strains of microorganisms elaborate substances of peptide nature which have antibacterial activity for other microorganisms. 1972F. M. Menger et al. Org. Chem. xiv. 359 The distinction between proteins and peptides is arbitrary. Compounds which have molecular weights greater than 10,000 are generally referred to as proteins. 1976Sci. Amer. Feb. 32/1 There are two large classes of hormones, the peptides and the steroids. Ibid. 32/2 A typical peptide hormone is insulin.., human insulin consists of 51 amino acid units. 1977Time 21 Nov. 40/3 Drs. Frank Ervin of U.C.L.A.'s Neuropsychiatric Institute and Roberta Palmour of the University of California at Berkeley described the substance as a variant of a peptide—a short chain of amino acids—that belongs to a family of newly discovered opiate-like brain hormones called endorphins.
2. Special comb.: peptide bond, a carbon–nitrogen bond of the type {b1}CO·NH{b1} in an organic molecule; spec. one between the carboxyl group of one amino-acid residue and the amino group of another; peptide chain, a linear sequence of amino-acid residues joined by peptide bonds; peptide linkage = peptide bond.
1935Jrnl. Biol. Chem. CXI. 249 Aminopeptidase, carboxypeptidase, and dipeptidase need in addition to a peptide bond a free amino group or a free carboxyl group. 1960New Biol. XXXI. 12 There are twenty main different kinds of amino acid involved in protein make-up, though they are basically alike enough to be all connected to each other by the same kind of chemical link (the peptide bond) to form the chain. 1964N. G. Clark Mod. Org. Chem. xiii. 252 Many important natural products contain the ‘amide-linkage’ or peptide bond, {b1}CO·NH{b1}; thus, the peptides and proteins..are long-chain polyamides.
1931Nature 2 May 664/2 There is a strong probability that..many proteins will be based on a roughly constant weight of peptide chain. 1935Jrnl. Biol. Chem. CXI. 245 Lysine is coupled in the long peptide chains of proteins with its α-amino and carboxyl groups. 1970R. W. McGilvery Biochem. ii. 9 A protein may be only a single, long, peptide chain, but most proteins are made of several peptide chains associated together.
1925Proc. R. Soc. B. XCVIII. 59 This procedure was adopted in order to bring about the scission of the peptide linkages as rapidly as possible. 1964N. G. Clark Mod. Org. Chem. xvii. 349 Proteins and polypeptides consist of chains of amino-acids linked via amide formation between the carbonyl group of one acid and the α-amino group of the next (the typical linkage, {b1}CO·NH{b1}, is often called a peptide-linkage or -bond). |