AVIDIN .5. QUENCHING OF FLUORESCENCE BY DINITROPHENYL GROUPS
AVIDIN .5. QUENCHING OF FLUORESCENCE BY DINITROPHENYL GROUPS
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DOI：
10.1042/bj0900564
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发表时间：
1964-01-01
影响因子：
4.1
通讯作者：
GREEN, NM
中科院分区：
文献类型：
--
作者：
GREEN, NM
变性抗生物素蛋白（350 m[mu]）、天然抗生物素蛋白（338 m[mu]）和抗生物素蛋白-生物素复合物（328 m[mu]）的荧光最大值的位置证实了从紫外差光谱得出的结论，即色氨酸环境的极性在从变性抗生物素蛋白经过天然抗生物素蛋白到抗生物素蛋白-生物素复合物的过程中降低。从二硝基苯化程度与荧光之间的关系可知，单个DNP基团可以猝灭抗生物素蛋白分子至少90%的荧光。当生物素的二硝基苯酰肼被结合时，荧光也被猝灭。从荧光滴定曲线的形状可以看出，亲和素的三个结合位点在一级近似下是独立的，并且与生物素随机结合。亲和素的荧光被结合的硫辛酸淬灭，这是由于其在330 m[mu]处的弱吸收带。
The positions of the fluorescence maxima of denatured avidin (350 m[mu]), native avidin (338 m[mu]) and the avidin-biotin complex (328 m[mu]) confirmed the conclusion drawn from ultraviolet difference spectra that the polarity of the tryptophan environment decreases on going from denatured avidin, via native avidin, to the avidin-biotin complex. From the relation between extent of dinitrophenylation and fluorescence it was shown that a single DNP group could quench at least 90% of the fluorescence of an avidin molecule. The fluorescence was also quenched when the dinitrophenylhydrazide of biotin was bound. From the shape of the fluorescence-titration curve it was shown that to a first approximation the three binding sites of avidin were independent and combined at random with biotin. The fluorescence of avidin was quenched by bound lipoic acid, as a consequence of its weak absorption band at 330 m[mu].