DETERMINING MOLECULAR MASS AND KINETIC PARAMETERS OF VIETNAM YELLOW SOYBEAN UREASE

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.