【摘要】 用分光光度法研究了蛋白质与四氰代二甲基苯醌 (TCNQ)之间的荷移反应 .通过对影响反应因素的研究 ,确立了以形成荷移 (C T)配合物测定蛋白质的最佳反应条件 ,在V(丙酮 )∶V(水 ) =1∶4,pH =9.8的溶液中 ,配合物在 42 5nm处有最大吸收 ,BSA在 0～ 40 μg/mL及 5 0～ 3 0 0 μg/mL符合朗伯 -比尔定律 ,摩尔吸光系数分别为 2 .43× 10 5L·mol-1·cm-1和 2 .90× 10 5L·mol-1·cm-1.分别用平衡透析法、双波长法和摩尔比法研究了蛋白质与TCNQ的结合方式并测定了最大结合数 .当TCNQ浓度较小时 ,与蛋白质的结合符合Scatchard规则 ,存在两类结合方式 ,具有不同结合常数 ;TCNQ浓度较高时 ,符合Plasvento相分配模型 ,分配常数为一定值 .用拟合的方法测定了人血清样品中的蛋白质 ,与考马斯亮蓝法测定结果吻合 ,回收率为 98%～10 4% .更多还原

【Abstract】 The charge transfer complexes of 7,7,8,8 tetracyanoquinodimethane (TCNQ) with five proteins have been studied by spectrophotometry. The complexes exhibit maximum absorption band at 425 nm in the solution of acetone/water (1∶4, V/V ) at pH=9.8. The charge transfer absorbance obeys the Beer’s law within the concentration ranges of 0～40 μg/mL and 50～300 μg/mL for BSA. The most suitable conditions have been established, which can be used to determin the contents of proteins by measuring the charge transfer absorbance. The molar absorption coefficients of the BSA TCNQ complex were determined to be 2.43×10 5 L·mol -1 ·cm -1 and 2.90×10 5 L·mol -1 ·cm -1 . The composition of the charge transfer was investigated and the binding numbers of the BSA TCNQ complex were studied by equilibrium dialysis, dual wavelength and molar ratio methods, which gave similar results. Proteins in human serum have been determined with the new method, which afforded values very close to that obtained with Coomassie brilliant blue G 250 method. The recoveries of albumin were in the range of 98% to 104%.更多还原