棉花病菌Xanthomonas campestris pv.malvacearum的一种具特异肽键专一性的胞外蛋白酶的纯化与鉴定  

PURIFICATION AND CHARACTERIZATION OF AN EXTRACELLULAR PROTEASE WITH UNUSUAL PEPTIDE BOND SPECIFICITY FROM XANTHOMONAS CAMPESTRIS PV. MALVACEARUM

作　　者：黄晶[1] Robert K Gholson Carol R Rokerts 毛大璋[3] 安锦华 

机构地区：[1]Pharmagenesis,4831 Porter Drive,Palo Alto,Califormia 94304,USA [2]Oklahoma State University,Stillwater,Oklahoma 74078,USA [3]中国科学院植物研究所

出　　处：《Acta Botanica Sinica》1997年第5期415-421,共7页Acta Botanica Sinica（植物学报：英文版）

摘　　要：棉花病原体Xanthomonas campestris pv.malvacearum在酪蛋白(脱脂奶)存在下生长时产生胞外蛋白酶活性,其中至少包含3种蛋白酶,表观分子量分别为29(蛋白酶-1)、38和43kD。 蛋白酶-1被纯化,其最适pH在5.5～7.5之间。抑制研究表明蛋白酶-1可被Phosphoramidone、EDTA及1,10-邻二氮杂菲抑制,然后用锌离子温育重新激活,说明这是一个金属蛋白酶。发现蛋白酶-1特异地裂解肽链的天冬氨酸残基或半胱氯酸残基的氨基端侧,这种高度的肽键专一性预示这个酶在蛋白质链顺序分析中及由较大蛋白质制备特定多肽方面可能十分有用。The cotton pathogen Xanthomonas campestris pv. malvacearum produces extracellular protease activity when grown in the presence of casein-proteins (skim-milk) . At least three proteases are produced with apparent molecular weights of 29 kD, 38 kD and 43 kD. Protease-1 can be inhibited by phosphoramidone, EDTA and 1, 10-phenanthroline and reactivated by incubating with zinc ions, suggesting that protease-1 is a metalloprotease. It was found that protease-1 only cleaved the peptide bond of aspartic acid and cysteic acid from N-terminal side, confirming previous observations . This property could be very useful for protein sequence analysis and preparation of specific peptides from larger proteins.

关 键 词：棉花疫病 棉花病菌 胞外蛋白酶 

分 类 号：S435.621.2[农业科学—农业昆虫与害虫防治]