Alcohol Dehydrogenases in Strawberry Pulp

Abstract

NAD-dependent alcohol dehydrogenase (NAD-ADH, EC 1. 1. 1. 1) and NADP-dependent alcohol ehydrogenase (NADP-ADH, EC 1.1.1.2) were extracted from strawberry pulp and partially urified with ammonium sulfate fractionation and DEAE-Sephadex A-50 column chromatography. he pH optima of reduction and oxidation with NAD-ADH are 6.0 and 9.0, respectively. On the ther hand, those of NADP-ADH are 8.5 and 9.5, respectively. NAD-ADH is stable in the pH ange between 6.5 and 8.5. NADP-ADH is stable in the pH range between 6.5 and 9.5. Free ulfhydryl groups are essential for the activities of these enzymes as PCMB and o-iodosobenzoic acid ause a drastic inhibition. NAD-ADH reacts only with aliphatic alcohol and aldehyde, while aromatic and terpene alcohols and aldehydes are the better substrates for NADP-ADH than aliphatic nes. These two ADHs in strawberry pulp are supposed to be the same as ADHs found in strawberry seeds from their chemical and physical properties and zymograms on polyacrylamide gel lectrophoresis.