桑叶凝集素分离纯化及抑菌活性研究

Separation and Purification of Lectin from Morus alba L. and Its Antimicrobial Activity

采用磷酸缓冲液提取桑叶凝集素,经硫酸铵分级沉淀法初步纯化、Cellulose DE-52阴离子柱层析、CMSepharose Fast Flow阳离子柱层析、Sephadex G-75分子筛柱层析对其进行逐级纯化,采用牛津杯法进行抑菌活性测试。结果表明桑叶凝集素经聚丙烯酰胺凝胶电泳检测显示为单一条带,SDS聚丙烯酰胺凝胶电泳检测其亚基分子量为35.95、30.35 KD;该凝集素对供试菌具有较好的抑制作用,对绿色木霉、苹果落叶病菌、西瓜枯萎病菌及烟草黑胫病菌抑菌直径分别为20、30、15、18 mm。桑叶凝集素具有较好的抑菌活性,可为新农药创制领域提供有用的天然产物先导化合物。

Morus alba lectin was firstly extracted with phosphate buffer and followed by a series of purification including ammonium sulfate graded precipitation. Further separation was carried out using Cellulose DE-52 chromatography,CMSepharose Fast Flow chromatography and Sephadex G-75 sieve chromatography. The antimicrobial activity of M. alba lectin was finally tested using Oxford Cup method. The results showed that M. alba lectin displayed a single band detected with SDS polyacrylamide gel electrophoresis method and presented as 35. 95 KD and 30. 35 KD molecular weight. The lectin exhibited an inhibitory effect against Trichoderma viride,Alternaria alternata f. sp. mali,watermelon fusarium wilt and Phytophthora parasitica with antibacterial circle diameter of 20,30,15 mm and 18 mm,respectively. In summary,M.alba lectin exhibited an effective antimicrobial activity and therefore can be used as an useful natural lead compound for discovering and developing novel agrochemicals.