Dehydrase

Pronunciation

• RP enPR: dÄ“hīʹdrāz, IPA: en, /diːˈhaɪdɹeɪz/, /diːˈhaɪdɹeɪs/

Origin

Formed as - + de + - + hydr + -, by analogy with the German Dehydrase.

Full definition of dehydrase

Noun

1. (biochemistry, disused) dehydrogenase
• 1914, Chemical Abstracts Service, volume 8, page 3,051It is shown by means of a typical dehydrase, Schardinger’s milk enzyme, that oxidase, reductase and mutase are 1 and the same enzyme.
• 1939, Thomas Edward Thorpe, A Dictionary of Applied Chemistry ed., volume 3, page 553, column 2Citric acid dehydrase is present in the liver and in vegetable material acting on citric acid.
• 1959, N. Campbell contrib. and Ernest Harry Rodd ed., Chemistry of Carbon Compounds, volume 4B, chapter 8, page 942Freudenberg also postulates a second process whereby catechins in the presence of dehydrases undergo condensation by dehydrogenation.
2. (biochemistry, disused) dehydratase
• 1953, Advances in Enzymology, volume 14, page 243The usual English term ‘dehydrase’ for an enzyme dehydrating a substrate was changed to dehydratase, because Dehydrase in German…means a dehydrogenating enzyme rather than an enzyme splitting off water.
• 1957, Microbiology (journal), volume 16, page 480The enzymic dehydration of tartaric acid to oxaloacetic acid, first established…for the d-isomer, occurs also with the meso- and l-isomers, and the attack on all three tartaric acids by bacteria of the genus Pseudomonas appears to occur principally by means of stereospecific dehydrases.

Usage notes

The polysemic term dehydrase has been superseded by the more specific terms dehydrogenase and dehydratase since its proscription by the International Union of Biochemistry and Molecular Biology in 1961.

International Union of Biochemistry and Molecular Biology, Report of the Committee on Enzymes (1961), chapter 6, page 34

 The name ‘dehydrase’, which has been used for both dehydrogenating and dehydrating enzymes, will not be used. ‘Dehydrogenase’ will be used for the former and ‘dehydratase’ for the latter.