油麻藤凝集素的荧光光谱研究

Fluorescence Analysis of Lectin from Mucana Sempervirens Hemsl

用化学修饰、内源荧光和荧光淬灭等方法研究了油麻藤凝集素（ＭＳＬ）的溶液构象变化和微环境的构象特征。研究发现ＭＳＬ分子中总共有９个色氨酸（Ｔｒｐ）残基，它们的荧光能被丙烯酰胺淬灭，但不易为ＫＩ接近而淬灭，ＭＳＬ经Ｎ－溴代琥珀酰亚胺（ＮＢＳ）修饰后，其内源性荧光发射谱发生相应变化，结果表明ＭＳＬ分子中部分Ｔｒｐ残基埋藏于分子内部，而位于分子表面的Ｔｒｐ残基可能处于分子的疏水袋中。

The conformational changes and properties of microenvironment of lectin from Mucana sempervirens Hemsl. (MSL) were examined by chemical modification and fluorescence spectroscopy. Results showed that there were nine tryptophan (Trp) residues in MSL molecule. The fluoresecnce from these Trp residues were not quenched by KI ,but were 83% quenched by acrylamide. Modification of Trp residues with N-Bromosuccinimide induced changes in the fluorescence properties of MSL. These results implied that some of Trp residues were buried in the interior of MSL, and Trp residues in the surface of MSL were located in the hydrophobic pocket of the glycoprotein.