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作 者 ：陶应双 胡忠

期 刊 ：云南植物研究 1991年 13卷 04期 页码：1-3

关键词：美洲商陆；抗真菌蛋白；

Keywords:Phytolacca americana(Pokeweed,

摘 要 ：从美洲商陆(Phytolacca americanal L.)夏天采集的2—4年生宿根中分离了二种抗真菌蛋白，称为PAFP—R1和PAFP—R2。分离程序包括用盐溶液提取，经CM—Sephadex离子交换层析、凝胶过滤层析和羟基磷灰石柱层析纯化。在PGA培养基上，0.lmg/ml蛋白明显抑制木霉菌丝的生长；但对细菌的增殖，即使1mg/m1也无抑制作用。用SDS—PAGE测得二者的相对分子量各为13kD和15kD,单多肽链，等电点约为5.8。用酚-硫酸法未测出含糖。二 蛋白均高含半胱氨酸(19mol/mol)。用Edman降解法测得二者的N末端均为Ala。秋天采集的根中，这二种蛋白含量均很低,但富含由二条PAFP-R1肽链以双硫键联结的二聚体，它无抗真菌活性。冬天宿根中抗真菌蛋白主要成分是Mr为17kD的单肽链蛋白。上述蛋白对于人红血球均无凝集活性，因此不是PWM的成分。以上结果说明，商陆根中有多种具抗真菌活性的蛋白，成分随季节发生变化，它们都是不含糖，高含半胱氨酸，分子量小于20kD的单肽链蛋白。

Abstract:From summer harvested roots of 2-4 years old plants of Pokeweed, two antifungal proteins named PAFP-R1 and PAFP-R2 were isolated by using a procedure including extrac-tion with saline solution, purification with ion exchange chromatography on CM-sephadex, gel filtration on sephadex G50 and chromatography on hydroxyapatite. Both proteins at 0.1 mg/ml inhibited obviously the growth of Trichoderma viride mycelia on a PGA medium plates, but even at 1 mg / ml did not inhibit the multiplication of bacteria E. cola and B. subtilis. They are both a single polypeptide with Mr of 13 kD and 15 kD respectively, with a pi of about 5.8 and with Ala as the N-terminus.

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