豆薯种籽中一种抗真菌蛋白PaAFP的分离纯化和部分特性研究

各类植物由于缺少自身免疫系统的支持，因而必须依赖于其它机制来抵御外来微生物的入侵．其中的一种重要机制就是通过合成体内各类能抑制微生物生长的蛋白质来完成的［１］．已报道从植物中分离出多种不同的抗真菌蛋白．广为研究的是几丁质酶和β－１，３－葡聚糖酶，认为它们在植物对真菌病的抗性中起重要作用［２，３］；核糖体失活蛋白（ＲＩＰｓ）和一类富含半胱氨酸的碱性多肽Ｔｈｉｏｎｉｎｓ也显示有非专一的抗真菌活性［４，５］．但仍有一些蛋白质，体外表现强烈的抗真菌活性，却不属于以上范围［６，７］．本文报道了豆薯种籽中一…

Isolation,Purification and Partial Characterization of an Antifungal Protein PaAFP from Seeds of Pachyrrhizus erosus

An antifungal protein named PaAFP was isolated and purified from the seeds of Pachyrrhizus erosus by extraction with PB buffer, S Sepharose Fast Flow, CM 52 cellulose and Sephadex G 75 column chromatography. On potato sucrose agar medium, the purified protein obviously inhibited the growth of the important edible fungus pathogens Trichoderma viride and Chrysosporium luteum at 6 2 μg and 12 5 μg per disc respectively. The molecular weight was about 14 kD by SDS PAGE and HPLC. The isoelectric point was pH7 5. Analysis of the composition of amino acids showed that this protein was rich in Asx, but lacking in Met.