溴甲酚绿和蛋白质相互作用的电化学研究及应用

Electrochemical Studies on the Interaction of Protein with Bromocresol Green and Its Application

在pH 2.8的B-R缓冲溶液中,溴甲酚绿能与人血清白蛋白发生相互作用.以溴甲酚绿为电化学探针,用线扫极谱法对结合反应体系进行了研究.溴甲酚绿在-0.42V(vs.SCE)有一个良好的极谱还原峰,加入人血清白蛋白(HSA)后,其峰电位不变而峰电流下降,利用峰电流的下降可以测定HSA浓度.在所选择的最佳实验条件下,峰电流的下降值同HSA的浓度在4.0～60.0 mg·L-1范围内呈良好的线性关系,线性回归方程为△ip'(nA)=0.65+18.05c(mg·L-1),n=8,γ=0.992.本方法还可应用于牛血清白蛋白、牛血红蛋白、卵清白蛋白等多种蛋白质的测定.

In a Britton-Robinson （B-R） buffer solution of pH = 2.8, bromocresol green （BCG） can interact with human serum albumin （HSA） to form an supramolecular complex. This reaction was carefully studied with linear sweep polarography and the results showed that BCG could be used as an electrochemical probe for the determination of HSA and other proteins such as bovine serum albumin （BSA）, bovine hemoglobin, oval albumin and lipase. BCG had an well-defined second order derivative polagraphic reductire peak at -0.42 V （vs. SCE） and the addition of HSA in BCG solution could result in the decrease of the peak current without the movement of the peak potential, which indicated that the supramolecular complex was electrochemical inactive. The decrease of peak current is in good linear with the concentration of HSA in the range of 4.0～60.0 mg· L^-1 with the linear regression equation as Δip″（nA）=0.65＋18. 05c （mg·L^-1）, （n=8,γ=0. 992）and the detection limit as 3.0 mg·L^-1. This new electrochemical method was further applied to the determination of HSA content in real human serum.