Protein Kinase Activity and Insulin-binding Activity in Plant Basic 7S Globulin

抄録

Basic 7S globulin in soybean seeds is a cysteine-rich glycoprotein with insulin-binding activity, and has 27- and 16-kDa subunits linked by disulfide bonds. After N-glycanase treatment, the 27-kDa subunit did not react with insulin, but the 16-kDa subunit still did. Soybean seeds release much basic 7S globulin when immersed in hot water. Protein kinase activity was detected in the proteins released. The protein kinase activity of the globulin was measured by the phosphorylation method in a gel. The activity was conferred by the 16-kDa subunit. The 16-kDa subunit and the sugar chain of the 27-kDa subunit could bind with insulin, whereas protein kinase activity seemed to be associated with the 16-kDa subunit.