Characters of proteinase inhibitor isolated from streptomyces fradiae

Streptomyces fradiae에서 분리한 단백질 분해효소저해물질의 특성

The objective of the current study is to elucidate the biological roles of proteinase inhibitor in microorganisms. As the first step, a strain of Streptomyces fradiae was selected as a producer of extracellular proteinase inhibitor. The proteinase inhibitor was purified from culture broth through ultrafiltration, gel-filtration and ion-exchange chromatography. Molecular weight of the proteinase inhibitor was estimated to be 16, 800 by SDS polyacrylamide gel electrophoresis. It was found that the proteinase inhibitor inhibited only alkaline serine proteinases such as subtilisin, $\alpha$-chymotrypsin and Promase E but not trypsin and other proteinases. The mode of inhibition against Pronase E with succinyl-phenylalanine-p-nitroanilide as a substrate was competitive.

방선균의 세포분화와 관련된 연구의 일환으로 Streptomyces fradiae NRRL2702가 생성하는 단백질분해효소 저해물질을 분리정제하여 그 특성을 분석하였다. 즉 S. fradiaesm s일반 환경 조건하에서 단백질분해효소를 생성하나 특정 조건하에서는 그 단백질의 활성을 저해하는 저해제를 생성함을 알았다. 이 저해제의 분자량은 16,800이며 serine proteinasem이 일부만을 저해하는 특징이 있었다. Pronase E의 활성의 저해양상은 competitive inhibition 이었고 열에 대하여 매우 안정함을 알았다.