Abstract: The conditions of polymerization of soybean 11S globulins by microbial transglutaminase(MTGase)were studied.It was shown that only acidic subunits of 11sglobulins were polymerized by Tase,but basic subunits almost not.The catalytic activity of MTGase was higher at Ⅰ=0.1thanⅠ=0.5,perhaps due to effect of different ionic strenghs on its activity.The enzyme at different amounts(10～40U/g)could not affect the polymerization of acidic unit of 11S by TGase.The appropriate pH for polymerization of 11S by TGase was 7.0～8.0.At <50℃,the higher the temperature,the quicker the equilbrium.of polymerization by TGase was.The effect of polymerization at 37℃for 4h was the same to that of 50℃for 2h,but different at 60℃at which the enzyme was almost deactivated.

Key words: Micfrobial transglutaminase , Soybean protein , 11S globulin , Polymerization