棉花黄萎病菌毒素的纯化与特性研究

 用凝集素伴刀豆球蛋白(ConA)做配基的Sepharose 4B亲和层析纯化了毒素物质。分析证明病菌产生的毒素物质是一种酸性糖蛋白,其中蛋白质和糖的含量分别为85.26%和14.74%,每毫升纯化毒素中含蛋白质1.04mg、糖0.18mg。蛋白质中含17种氨基酸,酸性氨基酸占总量的18.4%,碱性氨基酸占8.3%。#br#纯化毒素糖蛋白具有明显的特性:对棉苗具有强烈地致萎作用,用病菌人工接种表现出同样的症状;在高离子浓度下毒素被降解,低离子浓度下,出现白色沉淀,致萎力减弱;经木瓜蛋白酶、a-淀粉酶、6NHCl水解后,对棉苗的致萎力分别降低7%、57%和93%。

PURIFIED TOXIN OF VERTICILLIUM DAHLIAE FROM COTTON AND ITS PROPERTIES

The toxin was purified by Sepharose 4B affinity electrophoretic analysis using agglutinin with sword Jackbean spherical albumen as medium. This toxin was shown to be a kind of acidic glycoprotein.Its protein and sugar contents were respectively 85.26% and 14.74%, i.e.1 ml of the sample contained 1.04mg of protein and 0.18mg of sugar. A total of 17 amino acids were recognized, in which acidic amino acids occupied 18.4% while basic 8.3%. This toxin was able to cause withering of the cotton seedlings with the similar symptoms as those produced by artificial inoculation. This toxin was degraded under high ionic concentration in which white precipitates were observed. Under low ionic concentration the toxin effect was lowered. The toxin effects of the purified glycoprotein albumen were lowered to 7%, 57% and 93% when hydrolyzed by papainase, α-amylase and 6N HCl solution respectively.