Study on the Interaction between Cefprozil and Bovine Serum Albumin by Spectrometry / 中国药房

ABSTRACT

OBJECTIVE:To study the interaction of cefprozil (CE) with bovine serum albumine (BSA). METHODS:Under the temperatures of 289,299 and 309 K,the interaction of CE with BSA for 50 min had been studied by fluorescence quenching, UV spectrometry and synchronous fluorescence spectroscopy. Quenching constant(KSV)and speed constant(Kq)were calculated by Stern-Volmer equation. Static quenching constant(KLB)was obtained by Lineweaver-Burk equation,and UV spectrogram was used to determine the type of quenching. Double logarithmic equation was used to calculate the binding constants (Kb) and the number of binding site(n). Thermodynamic equation was used to obtain ΔH,ΔS,ΔG. Hill's coefficients(nH)was obtained by Hill equa-tion. RESULTS:At three different temperatures,with CE concentration increasing,fluorescence intensity of BSA decreased regular-ly. The value of KSV,Kq,KLB,Kb and n and nH decreased with the temperature increasing. ΔH,ΔS and ΔG were lower than 0. The numbers of binding sites were approximately equal to 1 and nH<1. CONCLUSIONS:CE statically quench the fluorescence of BSA,and the binding of them have been found to certain extent. The process of binding is spontaneous exothermic process. The main binding forces include Hydrogen bonds and Van der Waals forces,and primary binding site for CE is located at sub-domain ⅡA of BSA. There was some negative cooperative effect. CE would not affect the conformation of BSA. The binding site of CE and BSA is near by tyrosine residue.