Properties of L- Alanine Dehydrogenase of Trichoderma viride PDF

Keywords

Trichoderma viride, L-alanine dehydrogenase, puruvate

Abstract

A study of the properties of L-alanine dehydrogenase of Trichoderma viride was undertaken. Maximal enzyme activity occurred at pH 8 for reductive animation of pyruvate, and at pH 9.5 for oxidative deamination of L-alanine at a temperature of 50 degree Celsius. Maximum velocity of the reductive animation reaction was ten times greater than that of the oxidative deamination reaction. The Km values for pyruvate, NH4+, NADH, L-alanine and NAD+ were 17.2, 166, 0.7, 6.06 and 7.14 mM respectively. The enzyme was not inhibited by EDTA, suggesting that no metal cation is participating in enzyme catalysis. This is supported by the finding that none of the tested metal salts activated the enzyme. Alternatively, the enzyme activity was inhibited by Fe2+, Mg2+, Ca2+, Cu2+, and Mn2+. SH groups don't seem to play a role in the catalytic action of the enzyme, as addition of iodoacetate or reduced glutathione did not effect the enzyme activity. Stability of the enzyme under different conditions was investigated.