不同SDS电泳法对家蚕低分子Kunitz型抑制剂分子量鉴定的影响

EFFECT OF DIFFERENT SDS-PAGE METHODS ON THE ESTIMATION OF THE MOLACULAR WEIGHT OF THE LOW MOLACULAR KUNITZ TYPE CHYMOTRYPSIN INHIBOTOR IN BOMBYX MORI

采用 15 %SDS聚丙烯酰胺凝胶电泳和tricine -SDS聚丙烯酰胺凝胶电泳分别对家蚕血液中低分子Kunitz型胰凝乳蛋白酶抑制剂CI - 13的分子量进行了检测 ,SDS -PAGE结果为12 .5kDa ,而tricineSDS -PAGE结果为 7.3kDa。另根据CI - 13的氨基酸组成 ,算出分子量为 7,113Da ,这表明tricineSDS -PAGE的结果与氨基酸组成测定值接近 。

Two methods, 15% SDS-PAGE (polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate) and tricine-SDS-PAGE, were used to detect the low molecular weight chymotrypsin inhibitor of Kunitz type, CI-13, in the haemolymph of silkworm, Bombyx mori . The molecular weight was 12.5 kDa and 7.3 kDa, respectively, as determined with 15% SDS-PAGE and tricine-SDS-PAGE. The molecular weight of CI-13 calculated based on its amino acid composition was 7,113 Da, very close to the result of the second method. Hence, tricine-SDS-PAGE is recommended for the identification of low molecular weight proteinase inhibitors.