脲引起反相胶束酵母醇脱氢酶的紫外与荧光变化

比较了ＡＯＴ－异辛烷及水相两种体系中脲引起的酵母醇脱氢酶（ＹＡＤＨ）紫外和荧光变化。在水相反应系统中随着脲浓度增加（至３．０ｍｏｌ／Ｌ），酶活性迅速下降并全部失活，构象发生重大改变，２２０ｎｍ处的紫外吸收增加，荧光强度减小，３３６ｎｍ处的荧光峰红移１２ｎｍ至３４８ｎｍ，在Ｒ＝１５的反相胶束体系中，酶浓度相同时ＹＡＤＨ活力相当于水相ＹＡＤＨ的６３％左右，但脲浓度增至３．０ｍｏｌ／Ｌ时ＹＡＤＨ的活力基本无变化，２４０ｎｍ和２７０ｎｍ处的紫外吸收峰、３５７ｎｍ处的荧光发射峰均随着脲浓度的增加有所升高。上述结果表明脲对两种体系中ＹＡＤＨ的分子构象和活力的影响是不同的

ULTROVIOLET AND FLUORESCENCE CHANGESOF YEAST ALCOHOL DEHYDROGENASE INDUCED BYUREA IN REVERSE MICELLES

The UV and fluorescence spectra of YADH in the presence of urea both in reverse micelles and aqueous system were studied. In aqueous phase, the results of increasing UV spectra at 220nm and decreasing the ralative fluorescence intensity at 336m, showed that the structure of YADH was unfolded and the enzyme was rapidly inactivated. However in reverse micelles system, the UV spectra at 240nm, 270nm and the relative fluorescence intensity at 357nm of YADH were increased with urea concentration. Contrary to the aqueous phase, the enzyme activity in reverse micelles is quite stable even in the presence of 3.0mol/L urea.