【摘要】 本文通过对黄花石蒜凝集素(Lycoris aurea Agglutinin,LAA)进行特殊氨基酸的化学修饰,显示一个LAA分子一共有8个色氨酸分子,其中有3个位于分子表面或近表面,Trp、Tyr和Ser/Thr不是LAA凝集活性所必需的氨基酸,而Asp/Glu的羧基和凝血活性密切相关,对其修饰后导致凝血活性丧失50%。通过荧光淬灭的方法对LAA分子中色氨酸所处微环境进行了研究。结果显示中性淬灭剂丙烯酰胺对LAA分子中色氨酸的淬灭作用最强可以淬灭100%的色氨酸荧光,其次是离子型淬灭剂碘化钾,能淬灭62.9%的色氨酸荧光,而氯化铯对LAA色氨酸的淬灭最弱,几乎不能淬灭LAA的荧光。更多还原

【Abstract】 Chemical modification studies on Lycoris aurea Agglutinin(LAA) demonstrated that LAA contains 8 Trp residues,among which about 3 Trp residues located the surface of protein and can be modified.Asp/Glu residues were essential for the hemagglutinating activity of LAA.However,chemical modification of Trp,Tyr and Ser/Thr didn’t affect the hemagglutinating activity of LAA.Fluorescence quenching study was carried out with three quenchers.Maximum quenching was observed with acrylamide,followed by iodide,quenching about 100% and 62.9% fluorescence of LAA,respectively.However,CsCl can not quench the intrinsic fluorescence of Trp residues.更多还原