海水小球藻抗菌蛋白的分离纯化及性质研究

Purification and Characteristics of Antimicrobial Protein from Chlorella pacifica

海水小球藻(Chlorella pacifica)提取液经硫酸铵沉淀、DEAE-52离子交换层析和SephadexG-200凝胶过滤层析后分离纯化出1种抗菌蛋白。经SDS-PAGE测定,两个亚基的相对分子量分别为61kD和70kD;该抗菌蛋白对热稳定,氨基酸组成分析表明含17种氨基酸,其中谷氨酸的含量最高,其次为甘氨酸与天冬氨酸,胱氨酸的含量最低。在抗菌活性中,纯化的蛋白质对产黄青霉(Penicillium chrysogenum)和中华根霉(Rhizopus chinensis)有较强的抑制作用,对金黄色葡萄球菌(Staphylococcus aureus)和肠炎病病原菌(Ameromonas punctata)也有抑制作用,其抗真菌活性比抗细菌强。

A antimicrobial protein was isolated and purified from Chlorella pacifica using ammonium sulfate precipitation, ion exchange chromatography on DEAE-52, and then gelfiltration on SephadexG-200. By SDS- PAGE determination, the protein appears two bands with molecular weight of 61 kD and 70 kD, respectively. The protein consists of seventeen amino acids, in which the contents of Glu, Gly and Asp are abundant. The protein had strong antifungal activity against Penicillium chrysogenum and Rhizopus chinensis, and also exhibited antibacterial activity against Staphylococcus aureus and A meromonas punctata The protein was stable under heat stress. Antifungal activities were stronger than antibacterial activitives in the antimicrobial protein from Chlorella pacifica.