Determination of the binding parameters of drug to protein by equilibrium dialysis/piezoelectric quartz crystal sensor

A novel method, equilibrium dialysis/piezoelectric quartz crystal sensor, a pplied to determine the binding parameters of diethyldithiocarbamate to hum an plasma protein is proposed. Based on the investigation of the equilibriu m reaction for the binding of drug to protein, the related theoretical equa tions for this binding were derived. By monitoring the frequency responses of a copper-plated piezoelectric quartz crystal sensor to drug in and out o f a dialysis membrane after equilibrium, the binding parameters were determ ined, i.e., 0.375 mu mol g(-1) for beta(p), 6.496 mu M for K-dp, 141.99 L m mol(-1) for K-p, and 0.043 for N. These values were in good agreement with reference values. It was found that this method may have application for st udying the characteristics of the interaction between other drugs and prote ins. (C) 2000 Academic Press.