【摘要】 百合科植物玉竹(Polygonatum odoratum(Mill.)Druce)的根状茎经生理盐水浸取、硫酸铵分级沉淀、CM-Sepharose柱离子交换层析和Sephacryl S-200凝胶过滤,得到经SDS-PAGE检测为14.2kD的单一蛋白条带的玉竹凝集素(Polygonatum odoratumlectin,简称POL).荧光淬灭剂丙烯酰胺、KI和CsCl对POL的内源荧光淬灭研究表明它们对凝集素分子荧光的淬灭过程属动态淬灭机制.其中玉竹凝集素中Trp残基对中性淬灭剂丙烯酰胺的可接近程度达到81%,而阴离子淬灭剂I-、阳离子淬灭剂Cs+仅淬灭POL 50%和45%的荧光.表明玉竹凝集素产生荧光的氨基酸残基大部分是位于分子表面和近表面带电荷的沟槽内,并且Trp残基周围有大约等量的正、负电荷分布.更多还原

【Abstract】 Polygonatum odoratum（Mill.） Druce lectin（POL） was isolated from Polygonatum odoratum（（Mill.））Druce by extraction,fraction with(NH₄)₂SO_4,ion exchange chromatography on CM-Sepharose column and followed by gel filtration on Sephacryl S-200.The purified POL shows a single band on SDS-PAGE of（14.2 kDa.）Fluorescence quenching study of POL by acrylamide, KI and CsCl suggested that they canquench 81%,50% and 45% of the intrinsic fluorescence of tryptophan in POL respectively,which indicated thatacrylamide is themost efficient quencher and nearly all the tryptophan residues of POL were located on the surface of the molecule,furthermore some of them were in groove of POL surface.更多还原