【摘要】 采用微孔比色法及荧光分析法 ,研究抗男性生育化合物棉酚与猪胰腺磷脂酶A2 (phospho lipaseA2 ,PLA2 ,EC3 1 1 4 )温育并透析前后对酶活力及荧光的影响 .结果表明 ,棉酚与PLA2 不可逆地结合明显地降低了PLA2 活力及荧光强度 .棉酚对酶活力抑制作用的IC50 为 35μmol L ;当其浓度达到 80 μmol L时 ,能够完全抑制PLA2 ( 4 11μmol L)对合成底物 2 硫代十六酰乙基磷酸胆碱(HEPC ,0 .2 5mmol L)的水解作用 .PLA2 的最大激发波长与发射波长分别为 2 75nm ,34 3nm ,荧光强度与酶浓度呈良好的线性关系 .棉酚对PLA2 的荧光具有较强的淬灭作用 .由于PLA2 与男性生育密切相关 ,棉酚对PLA2 活力的影响可能是其避孕作用及伴随的副作用的一种新的重要机制更多还原

【Abstract】 The effect of a male antifertility compound gossypol on the enzymatic activity and fluorescence of porcine pancreatic phospholipase A 2(ppⅠ PLA 2,EC 3 1 1 4)has been studied by microplate assay and fluorescence assay on the incubated mixture with or without dialysis.Gossypol interacted with ppⅠ PLA 2 resulting in forming a complex and diminishing enzymatic activity and fluorescence intensity.The drug enzyme interaction was irreversible by aqueous dialysis.The hydrolysis activity of ppⅠ PLA 2(4 11 μmol/L)toward a synthesized substrate 2 hexadecanoylthio 1 ethyl phosphorylcholine(HEPC,0 25 mmol/L)was completely inhibited by 80 μmol/L gossypol with an apparent IC 50 of 35 μmol/L.There was a good linearity between fluorescence intensities and concentrations of ppⅠ PLA 2 with maximal excitation and emission wavelength at 275 nm and 343 nm,respectively.Gossypol caused a red shift in the maximal emission of about 5 nm and strongly quenched the fluorescence intensity of ppⅠ PLA 2.Since PLA 2 is very important to male fertility,the influence of gossypol on PLA 2 probably correlates with its mechanism of male antifertility and adverse effect.更多还原