Chakravarty K, Varshney M, Maitra A
Department of Chemistry, University of Delhi, India.
Indian J Biochem Biophys. 1995 Apr;32(2):100-5.
The kinetics of enzyme catalyzed hydrolysis of penicillin G and stability of the enzyme alpha-penicillinase, entrapped in aerosol OT reverse micellar droplets have been investigated spectrophotometrically. Various physical parameters, such as, water pool size (related to Wo), pH and temperature, were optimized for maximum activity of penicillinase in water/aerosol OT/isooctane reverse micelles. The enzyme showed maximum activity of Wo - 14 and pH, 7.0. At any temperature the enzyme was to be more active in reverse micelles than in aqueous solution. At optimum conditions of Wo, pH and temperature the enzyme was 100% more active in reverse micelles than its maximum activity in aqueous solution. In both the systems, the activity starts falling at and above 25 degrees C. CD Spectral studies showed that the enzyme in reverse micelles possesses more helical structure than it has in aqueous solution and at the optimum conditions in which it showed maximum activity, the alpha-helicity was also maximum. The enzyme was very stable in reverse micelles at and above room temperature compared to the same in aqueous solution.
通过分光光度法研究了包埋在气溶胶OT反胶束微滴中的α-青霉素酶催化青霉素G水解的动力学及该酶的稳定性。对各种物理参数,如水池大小(与Wo相关)、pH值和温度进行了优化,以实现青霉素酶在水/气溶胶OT/异辛烷反胶束中的最大活性。该酶在Wo为14、pH值为7.0时表现出最大活性。在任何温度下,该酶在反胶束中的活性都高于其在水溶液中的活性。在Wo、pH值和温度的最佳条件下,该酶在反胶束中的活性比其在水溶液中的最大活性高100%。在这两种体系中,活性在25℃及以上开始下降。圆二色光谱研究表明,反胶束中的酶比水溶液中的酶具有更多的螺旋结构,并且在显示最大活性的最佳条件下,α-螺旋度也最大。与水溶液中的酶相比,该酶在室温及以上温度下在反胶束中非常稳定。