【摘要】 用硫酸铵分级沉淀、离子交换和HPLC层析等方法,从长白山药用真菌树舌的菌丝体中分离纯化了一种凝集素(Ganoderma applanatum lectin,简称GAL),SDS-PAGE检测其为单一蛋白条带。经过SDS-PAGE测得其亚基分子量为15kDa左右,HPLC分析分子量为58kDa左右,表明GAL由4个亚基组成。氨基酸组成分析表明,GAL中甘氨酸含量较高,不含蛋氨酸和色氨酸,中性糖含量约11.2%。圆二色CD谱显示其含有3.6%的α螺旋、46.8%的β转角和49.6%无规则卷曲,不含有β折叠。GAL可以凝集供试的2种动物血和3种血型人血的血红细胞,但对不同来源的血红细胞凝集滴度不同。糖抑制实验表明,只有棉籽糖和D-松三糖部分抑制GAL的凝血活性。GAL具有较好的热稳定性且其凝血活性不受Ca2+、Mg2+和Zn2+等二价阳离子的影响。更多还原

【Abstract】 A novel lectin（GAL）from the liquid cultured mycelia of medicinal fungus Ganoderma applanatum was purified by precipitation of 40%⁹0 %（ NH₄）₂SO₄, followed by ion chromatography DEAE Sephadex A-25 and HPLC. The purified lectin showed a single band on SDS-PAGE. The relative molecular mass of GAL was about 58kDa tested by HPLC, the subunit of GAL was about 15kDa determined by SDS-PAGE. This implied GAL was composed of four subunits. It contained a high content of glycin, the inexistence of methionine and tryptophan and 11.2% carbohydrates. Circular Dichroic spectra showed it contained 3.6% α-helix, 46.8% β-turn and 49.6% random without β-fold. GAL could agglutinated red blood cells, while its hemagglutinating activity for different resources of red blood was different. In a hemagglutination assay, D-Melezitose and Raffinose were the inhibitors of GAL among the sugars tested. GAL was thermo-stable and metal cations such as Ca²+、Mg²+ and Zn²+had no effects on GAL.更多还原