Purification of an enzyme separating outer layr of the cell wall of Micrococcus luteus

从藤黄微球菌（Micrococcus luteus）突变株IFO 3333的培养上清中分离到一种胞外蛋白，经超滤和Q-Sepharose FF和Sephacryl S-200 HR柱层析，在非变性聚丙烯酰胺凝胶电泳（PAGE）上均为均一蛋白。SDS-聚丙烯酰胺凝胶电泳（SDS-PAGE）结果显示，该蛋白分子量约为20万，分子量小于3万的蛋白质条带数条。扫描电镜观察显示，MT细胞四分体表面有许多颗粒均匀附着，而MT细胞四分体的包裹形成受到抑制。

An extracellular protein which showed activity inhibiting packets formation of Micrococcus luteus mutant strain MT was isolated from the culture supernatant of wild type strain IFO 3333.The protein obtained by ultrafiltration and column chromatographies with Q-Sepharose FF and Sephacryl S-200 HR was homogeneous on native polyacrylamide gel electrophoresis (PAGE). In SDS-PAGE, the protein gave a single protein band corresponding to a molecular weight of about 200,000 and several bands corresponding to molecular weights of less than about 30,000.Scanning electron microscopy revealed many particles attaching uniformly to the tetrads surface of MT cells whose packets formation was inhibited by cultivation with the protein.