摘要
通过对麦冬凝集素(OJL)进行特殊氨基酸的化学修饰,揭示了OJL所含的6个Trp残基只有1个位于蛋白表面,Trp、Tyr和Ser/Thr不是OJL凝集活性所必需的氨基酸,而Arg是维持其活性的必需基团.OJL在天然状态下荧光发射峰在328 nm处,Trp周围的极性较弱,处于疏水的微环境或Trp的吲哚环有特殊的构象.丙烯酰胺可以淬灭93.46%的色氨酸荧光,而CsCl和KI淬灭的程度较小,分别为41.25%和55.56%,证明Trp主要位于疏水环境.
Chemical modification studies on Ophiopogon japonicus lectin（OJL） demonstrated that OJL contains six Trp residues, but only one Trp residue located on the surface of the protein and can be modified. Axg were essential for the hemagglutinating activity of OJL. However, chemical modification Trp, Tyr and Set/ Thr was not effect on the hemagglutinating activity of OJL. The Max of the emmision peak of native OJL was at 328 nm exciting at 295 nm. Trp residue was around the polarity of the weaker, in the hydrophobic envi- ronment. Fluorescence quenching was carried out with three quenchers. Maximum quenching was observed with acrylamide, which can quench about 93.46 % fluorescence of OJL. However, the effect of Fluorescence quenching by CsCl and KI, which can not quench the intrinsic fluorescence of Trp residues, was lower. CsC1 and KI can quench about 41.25%, 55.56% fluorescence of OJL, respectively.
出处
《四川大学学报（自然科学版）》
CAS
CSCD
北大核心
2008年第6期1519-1526,共8页
Journal of Sichuan University(Natural Science Edition)
基金
国家自然科学基金(30000032,30270331)
关键词
麦冬凝集素(OJL)
化学修饰
荧光光谱
荧光淬灭
Ophiopogon japonicus Lectin, chemical modification, fluorescence spectrum, fluorescence quenching
