抗菌蛋白LCⅢ的分离纯化及其部分特性

Purification and Partial Characterization of An Antibacterial Protein LCⅢ

拮抗细菌Bacillus subtilis A014培养液上清经硫酸铵沉淀后,上CM52阳离子交换层析柱,分离出的峰Ⅲ具有对水稻自叶枯病菌(Xanthomonas campestris pv.oryzea)特异性抑制活性。进一步用快速液桐色谱(FPLC)的Mono S层析柱纯化并命名为抗菌蛋白LCⅢ。此蛋白质的分子量约26915 Da,等电点为9.12。氨基酸组成分析表明富含甘氧酸、苏氨酸、丝氨酸,缺少脯氨酸。经Edman降解法测出N末端28个氨基酸残基。根据其部分序列用计算机检索NBRF蛋白质文库,与所收入的已知蛋白质没有显著的同源性,表明是一种新的功能蛋白质。

Total proteins were precipitated by (NH_4)_2SO_4 from the overnight culture.supernatant of antagonistic bacterium Baoillus subtilis A014,applied to CM52 column and separated into three main peaks. The preparation of peak Ⅲ was showed to inhibit specifically the growth of rice bacterial blight pathogen Xanthoraonas campestris pv. oryzea, further purificated with Mono S column on FPLC and named antibacterial protein LC Ⅲ. The molecular weight of this protein is 26915Da, pI=9.12. Analysis of amino acid composition was revealed to be rich in glycine, threonine and serine, and deviod of proline. 28 amino acids of N-terminal were sequenced by the Edman degradation and computer analysis of this partial sequence found that antibacterial protein LC Ⅲ is a novel one.