干酪乳杆菌LC2W表面黏附相关蛋白的提取与鉴定

目的提取和鉴定干酪乳杆菌LC2W表面黏附相关蛋白,初步探索LC2W对胃癌细胞MKN-45细胞的黏附机制。方法LiCl处理、Sephadex G-75柱层析分离提取LC2W的表面蛋白,用黏附试验、电镜观察和SDS-PAGE电泳进行黏附相关蛋白的鉴定。结果LC2W经LiCl处理后,扫描电镜结果发现菌体表面粗糙但仍完整,黏附试验表明其对MKN-45细胞的黏附能力显著降低。提取到的表面蛋白的分子量分别为41.6、63.5、66.2 kDa。粗提物经柱层析后发现分子量为41.6 kDa的组分可以明显增强经LiCl处理过的菌体的黏附,而与未经处理的菌体黏附情况类似。结论表面蛋白参与了LC2W对MKN-45细胞的黏附,其主要活性成分的分子量为41.6 kDa。

Extraction and identification of adhesion-associated S-layer proteins of L. casei LC2W

Objective To extract and identify the S-layer proteins of Lactobacillus casei LC2W that associates with adhesion and preliminarily study the mechemism of LC2W adhesion on MKN-45 cells. Method S-layer proteins were extracted by LiCl and isolated by Sephadex G-75. Then the adhesion assay, electron microscopic observation and SDS-PAGE were used to identify the S-layer protein associated with adhesion. Result After the treatment of LiCl, electron microscopic observation showed that the surface of LC2W was rough but the cells were still in their integrity. The ability of adhesion to MKN-45 cells was significantly reduced. S-layer proteins of LC2W were composed of three proteins with molecular weights of 41.6, 63.5 and 66.2 kDa, respectively. After the isolation by Sephadex G-75, it was found that the 41.6 kDa fraction could significantly improve the adhesion of LC2W treated by LiCl and the adhesive ability of the treated cells amounted to the level of the normal ones. Conclusion The S-layer proteins were involved in the adhesion of LC2W on MKN-45 and the active component was the protein with molecular weight of 41.6 kDa.