Partial purification and properties of Cunninghamella elegans L-alanine dehydrogenase.
L-Alanine dehydrogenase was partially purified from the mycelial extracts of Cunninghamella elegans. The purified enzyme was fractionated by TEAE-cellulose column chromatography into two fractions (subunits) designated as fractions I and II. The activity of both fractions in the aminating reaction is 8 times higher than the activity of the deaminating reaction. pH-Optimal for reductive amination of pyruvate by both fractions were 8 and 10 for oxidative deamination of L-alanine. The Km values of fractions I and II for L-alanine, NAD+, pyruvate, NH4+ and NADH were estimated. Both fractions of L-alanine dehydrogenase were absolutely specific for L-alanine in the oxidative deamination reaction. Maximal activity of both fractions occurred at 40 degrees C. Inhibition by iodoacetate and activation by SH-compounds suggest that sulfhydryl groups may participate in enzyme activity. The 2 fractions were activated with Co2+, Fe2+, Ca2+, Mg2+ and Mn2+ ions, while Zn2+ inhibited both fractions. Stability of the enzyme under different conditions was investigated.
el-Awamry
Z A
ZA
Faculty of Science for Girls, Al-Azhar University, Cairo, Egypt.
el-Rahmany
T A
TA
D000409:Alanine / Q000378:metabolism; D050788:Alanine Dehydrogenase; D000594:Amino Acid Oxidoreductases / Q000302:isolation & purification* / Q000378:metabolism; D002853:Chromatography, Liquid; D003636:DEAE-Cellulose / Q000031:analogs & derivatives; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009090:Mucorales / Q000201:enzymology*; D010084:Oxidation-Reduction; D011773:Pyruvates / Q000378:metabolism; D013379:Substrate Specificity; D013696:Temperature
D011773:Pyruvates; D003636:DEAE-Cellulose; C010359:triethylaminoethyl cellulose; D000594:Amino Acid Oxidoreductases; D050788:Alanine Dehydrogenase; D000409:Alanine