Separation of trypsin inhibitor from soybean using reverse micellar system

Abstract

The separation of soybean trypsin inhibitor using reverse micellar system was investigated. Solubilization of the trypsin inhibitor was observed when the pH of the buffer was above isoelectric point (pI) of the enzyme, and de-solubilization was observed when pH was below pI. Among the buffer systems tested, 1.0 M CaCl$_2$ solution (pH 3.0) an 1.0 M NaCl solution (pH 11.5) were most effective for solubilization and de-solubilization, respectively. The optimum concentration of AOT in organic phase was 50 mM. These optimized conditions were applied to two model samples and the real smaple. In the case of a model sample composed of the same amounts of 7S protein and trypsin inhibitor, the specific activity was increased two folds, and in case of a model sample, composed of soluble soybean proteins isolate, he specific activity was increased 1.6 folds, when separating trypsin inhibitor from real sample of kwang Gyo, the specific activity was increased 1.56 folds. All trypsin inhibitors recovered by reverse micellar system were applied to SDS-PAGE and the resulting inhibitor was found to be highly pure.