香灰菌凝集素的纯化及其部分性质

Purification and Partial Characterization of the Lectin from Hypoxylon sp.

摘要:

香灰菌菌丝体经磷酸缓冲液抽提、20%-70%饱和浓度的硫酸铵沉淀、DEAE-Cellulose和Sephadex G-100柱层析纯化得到香灰菌凝集素(Hypoxylon sp. lectin, 简称HSL)。HSL经PAGE检测为单一蛋白条带, SDS-PAGE测得其亚基分子量为15.9 kD。过碘酸-Schiff染色法表明HSL为一种糖蛋白, 糖基的含量为15.5%, β-消去反应测得其糖和蛋白质的连接键为O-型糖肽键。HSL能凝集多种动物红细胞和人的红细胞, 在所测试的红细胞中, 对兔红细胞的凝集作用最强。HSL对热较敏感, 经50°C处理10 min, 其凝集活性明显降低, 其在碱性环境中较稳定, 而在酸性环境中较不稳定。HSL的凝集活性受Al3+、Fe3+、Ca2+和Zn2+等阳离子的影响。对鼠红细胞的凝集作用可被半乳糖和乳糖所抑制。

Abstract:

The novel lectin was isolated from the mycelium of Hypoxylon sp. by phosphoric acid buffer, precipitation of 20%-70% (NH4)2SO4, DEAE-Cellulose and Sephadex G-100 chromatography. It turned out to be a single band in PAGE. SDS-PAGE showed the subunit of Hypoxylon sp. lectin (HSL) was 15.9 kD. HSL was glycoprotein through dyed by Periodic acid-Schiff reaction, and the carbohydrate content was 15.5%. β-Elimination revealed the bond between the polysaccharide and the protein of HSL was O-type glucopeptide one. The HSL could agglutinate erythocytes regardless of blood type or animal species. HSL was less thermostable, and the hemagglutinating activity declined obviously after being heated 10 min under 50°C. The HSL was alkali-stable but not acid-stable. Its activity was affected by Al3+, Fe3+, Ca2+ and Zn2+. The hemagglutination of the lectin on mouse erythrocytes was inhibited by galactose and lactose among the sugars tested.