L-Alanine dehydrogenase was partially purified about 13-lold in a two-step
purification from the cell free extracts of Aspergillus tettcvs. Maximal enzyme activity
occurred at pH 8.6 for reductive arnlnatlon of pyruvate, where pH 10.4 for oxidative
deamination of L-alanine and at a temperature of 25°C. The Km values for pyruvate.
NH:, NADH, L-alanine and NAD' were 4, 175.4, 0.526, 16.13 and 3.3 mM
respectively. The enzyme activity was activeted by CO",Fe", ln²' , Ca". and Cu²'.
SH groups don't seem to playa role in the catalytic action of the enzyme as addition
of roooacetate or dithiothreitol did not effected the enzyme activity. Stability of the
enzyme under different conditions was investigated.