Analysis by capillary electrophoresis of the proteolytic activity of a Bacillus subtilis neutral protease on bovine caseins

Capillary electrophoresis using an untreated fused-silica capillary and a low-pH buffer containing urea and hydroxypropyl methyl cellulose was used to follow the proteolytic action of neutral protease of Bacillus subtilis on isolated casein fractions and whole milk casein (CN) samples. Electrophoretic analysis showed that this protease caused intense hydrolysis of alpha-CN, beta-CN and kappa-CN. The breakdown products due to the attack of the neutral protease on beta-CN, gamma(2)-CN A, gamma(1)-CN B, gamma(1)-CN A(1), gamma(3)-CN B, gamma(1)-CN A(2), gamma(3)-CN A, beta-CN-I A(1), beta-CN-I A(2) and beta-CN-I B, and on alpha(s)-CN, alpha(s0)-CN-I, alpha(s0)-CN-I and alpha(s1)-CN f(1-23) were separated. (c) 2007 Elsevier Ltd. All rights reserved.