五氯酚对人胎盘碱性磷酸酶构象与活力的影响

The effect of pentachlorophenol on the conformation and catalytic activity of human placental alkaline phosphatase

目的；研究三氯酚对人胎盘碱性磷酸酶构象与活力的影响。材料和方法：应用荧光光度法检测不同浓度五氯酚溶液中人胎盘碱性磷酸酶的内源荧光发射光谱，用分光光度法测定其活力。结果：五氯酚浓度小于1．0mmol／L时,平衡态酶的内源荧光发射强度及其活力迅速下降，发射峰位明显红移；继续提高五氨酸浓度，其荧光发射强度与活力逐渐下降，发射峰位仍在缓慢红移；五氯酚浓度增至5．0mmol／L时，荧光淬灭，但酶仍保密51．4％的活力。结论：五氯酚抑制了酶活力，并使其构承发生了改变，但其整体构象并未破坏。

Purpose: To study the effect of pentachlorophenol (PCP) on the conformation and catalytic activityof human placental alkaline phosphatase (PLAP. E. C. 3. 1. 3. 1). Method: Fluorometry was used to observethe intrinsic fluorescence emission spectra. and spectrophotometry was used to measure the activity of PLAP inPCP solutions of different concentrations. Result: The PCP concentrions lower than1. 0 mmol /L, the enzyme activity and fluorescence mtensity rapidly decreases with a marked red shift of emissionmaximum. The PCP c0ncentrations higherthan 1. 0 mmol/L,the enzyme activiy and fluoresence intensity gradu-ally decreases with a continuous red shift of emission maximum in PCP solutions of increasing concentrations. At5. 0 mmol/L PCP, the enzyme intrinsic fluorescence quenched and the enzyme activity is 51. 4%. Conclusion:The PLAP activity is inhibited and its conformation is changed . Whereas the whole conformation of the enzymeis not disrupted by PCP.