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 α-CN, β-CN and κ-CN. The breakdown products due to the attack of the neutral protease on β-CN, γ2-CN A, γ1-CN B, γ1-CN A1, γ3-CN B, γ1-CN A2, γ3-CN A, β-CN-I A1, β-CN-I A2 and β-CN-I B, and on αs-CN, αs1-CN-I, αs0-CN-I and αs1-CN f(1–23) were separated.