English

Noun

dehydrase ‎(plural dehydrases)

1. (biochemistry, disused) dehydrogenase
   • 1914, Chemical Abstracts, volume 8, page 3,051

     It is shown by means of a typical dehydrase, Schardinger’s milk enzyme, that oxidase, reductase and mutase are 1 and the same enzyme.

   • 1939, Sir Thomas Edward Thorpe, A Dictionary of Applied Chemistry [4th ed.], volume 3, page 553, column 2

     Citric 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 942

     Freudenberg 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 243

     The 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, Journal of General Microbiology, volume 16, page 480

     The 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• The polysemic term dehydrase has been superseded by the more specific terms dehydrogenase and dehydratase since its proscription by the IUBMB in 1961.^[1]

References

• “dehydrase” listed in the Oxford English Dictionary [2nd ed., 1989]

1. ↑ 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.