co-ˈenzyme Chem.
[ad. G. ko-enzym (Buchner and Katte 1908, in Biochem. Zeitschr. VIII. 524), f. co- 3 b + enzyme.]
A non-protein organic compound with which an enzyme needs to combine to become active and which generally takes part in the reaction as a carrier.
| 1908 Chem. Abstr. 2568 (title) The co-enzyme of the yeast press-juice. 1936, 1961. [see apo-enzyme]. 1941 Ann. Reg. 1940 344 Vitamin H proved identical with biotin, a growth factor for yeast, and with coenzyme R. 1947 Thorpe's Dict. Appl. Chem. VIII. 612/2 Coenzymes will be designated by the name of the enzyme activated, preceded by the prefix co- (example, coglyoxylase). 1950 Endeavour IX. 145/1 The entire enzyme or holoenzyme is built up of at least two fractions: (a) The apoenzyme, which is always a protein; it is colloidal and thermolabile. (b) The co-enzyme, of variable chemical constitution, frequently a phosphoric ester and sometimes a metallic derivative; very often the co-enzyme, which is non-colloidal, is fairly thermostable. |
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Add: 2. Special Comb. coenzyme A [f. acetylation n.], a coenzyme mononucleotide which acts as a carrier of acyl (esp. acetyl) groups, and which is synthesized from pantothenic acid.
| 1947 Novelli & Lipman in Arch. Biochem. XIV. 23 More recently this coenzyme was recognized as a pantothenic acid derivative..for which the term coenzyme A was introduced. 1977 Ann. Internal Med. LXXXVI. 338/1 Brain acetylcholine is synthesized by combining molecules of choline and of acetyl coenzyme A, a process catalyzed by the enzyme choline acetyltransferase. 1988 Biofactors I. 267/1 Coenzyme A esters are the substrates and regulators of many enzymatic reactions, among them condensations,..acylations, isomerizations and epimerizations. |