Abstract

In previous reports in this series, we found out the effective purificution process of urease from Viet Nam yellow soybean. The pure soybean urease powder (8.44UI/mg powder) from the purification process was used to determine some properties. Polyacrylamide gel 7,5% electrophoresis, non SDS and B-mercaptoetanol, compare with standard proteins from 35 000 – 400 000Da, showed Viet Nam soybean urease's molecular mass about 440 000 Da. The soybean urease was heated with SDS and B-mercaptoethanol, then SDS - acrylamide gel 10% electrophoresis, compare with standard proteins 10 000 - 250 000 Da, indicated that there exists a single Viet Nam soybean urease subunit species with a size of about 17 000 Da. Kinetic parameters of Viet Nam yellow soybean urease, determined according to Lineweaver – Burk equation, are Km = 5.3 mM and Vmax = 6.77*10 mm/min.