摘要
利用荧光光谱方法研究了红花菜豆凝集素（Ｐｈａｓｅｏｌｕｓｃｏｃｃｉｎｅｕｓｖａｒ．ｒｕｂｒｏｎａｎｕｓｌｅｃｔｉｎ，简称ＰＣＬ），结果表明ＰＣＬ分子各亚基中的两个色氨酸（Ｔｒｐ）残基分别位于ＰＣＬ分子表面和分子内。标记了ＤＮＳ的ＰＣＬ荧光偏振研究指出，致使ＰＣＬ在１０ｍｍｏｌ／ＬＳＤＳ条件下失活的主要原因可能是亚基解离。荧光偏振研究还表明，甲状腺球蛋白、甘露聚糖、海参多糖硫酸酯可与ＰＣＬ结合。荧光探针ｂｉｓ－ＡＮＳ与ＰＣＬ的结合可引起明显的荧光增强和发射谱蓝移，表明ＰＣＬ分子中存有疏水区域。结合了的ｂｉｓ－ＡＮＳ还可和ＰＣＬ中的Ｔｒｐ发生能量传递。
The fluorescence of Phaseolus coccineus var. rubronanus lectin (PCL) was studied in this paper. The results indicated that one of the two tryptophan residues in each subunit was located near the surface of PCL molecule, and the other one was in the internal region(actually in the interface region between the subunits). The fluorescence ploarization study of the DNS-labeled PCL indicated that the inactivation of PCL in the presence of 10mM SDS might be mainly induced by the dissociation of PCL molecule. The fluorescence ploarization study also indicated that thyroglobulin, mannan and trepang polysaccharide sulfate could bind to PCL molecule. The increase in fluorescence intensity and the emission spectral blue shift of fluorescence probe bisANS( 1 , 1 '-bi (4-anilino) naphthalene-5, 5'-dissulfonic acid) upon its binding to PCL molecule indicated that there was a hydrophobic region in PCL molecule. The energy transfer between the bound bis-ANS and the tryptophan residues in PCL was observed.
