【摘要】 本文以人红细胞膜乙酰胆碱酯酶力作用对象,研究了甲素浓度、pH、温度等因素对甲素致敏的酶光失活的影响,并计算了不同条件下的酶失活速率常数.甲素与某些光敏化剂相比,有以下特点:(1)甲素光敏化效率随着pH降低而增加,(2)光强指数α>1,(3)甲素在400nm—600nm波长范围内均有较大的光敏化作用.后性氧清除剂的试验结果表明,乙酰胆碱酯酶的光失活主要是单线态氧的作用,其它活性氧也有一定作用.更多还原

【Abstract】 The effects of photosensitizer (hypocrellin A) concentration, light intensity, medium pH and temperature on the photoinactivation of ace-tylcholinesterase in human erythrocyte membrane have been investigated in this work. The rate constants of inactivation of the enzyme were determined. The uniqueness of Hypocrellin A (HA) -induced inactivation, as compared with those of other photosensitizers, is revealed by following phenomena: (1) the photosensitization efficiency of HA increases as the pH decrease; (2) the light intensity exponent of the first-order rate equation is greater than 1; and (3) HA has a broaber photosensitization spectrum-range(400nm-600nm). The resuIts of active oxgyen -quenching experiments show that photoinactivation of the enzyme is mainly caused by singlet oxygen, while other forms of active oxygen also play a minor role in it.更多还原