中文摘要：

淬灭剂CsCl、KI、丙烯酰胺对黄精凝集素Ⅱ（Polygonatum cyrtonema Hua．LectinⅡ，PCLⅡ）内源荧光淬灭研究表明它们对凝集素分子的淬灭属动态淬灭机制．综合3种淬灭剂对黄精凝集素Ⅱ的淬灭效果，黄精凝集素Ⅱ中Tyr和Trp对中性淬灭剂丙烯酰胺的可接近程度分别达到88．5％和74．07％，而对阴离子淬灭剂KI为55．5％和66．7％，对阳离子淬灭剂CsCl均只有25％．表明黄精凝集素Ⅱ发射荧光的氨基酸残基大部分是位于分子表面疏水袋中，少部分埋藏于分子内部疏水环境中，且所有发荧光氨基酸所处微环境带正电荷的比例比带负电荷的比例大近一倍．

英文摘要：

The effects of quenchers on the micro-environment and conformation of Polygonatum cyrtonema Hua. Lectin Ⅱ （PCL Ⅱ ）were studied by fluorescence and quenching of intrinsic fluorescence analysis. Fluorescence studies of PCL Ⅱ indicated that tryptophan residues locate in a relatively hydrophobic region. Fluorescence quenching showed that acrylamide, KI and CsCl are able to quench 74.07%, 66.7%, 25% of the intrinsic fluorescence of tryptophan and 88.5 %, 55.5 %, 25 % of the intrinsic fluorescence of tyrosine in PCL Ⅱ, respectively. Furthermore, the kinetics of quenching reactions was only due to dynamic quenching processes. The extent of quenching observed was the highest with acrylamide, lower with KI, and the lowest with CsCl, further supporting that tryptophan residues are partially buried in a relatively hydrophobic core or predominantly positively charged areas near the surface of the PCL Ⅱ molecule.