On the interaction between cefonicid sodium and bovine serum albumin by spectrometry / 安徽医科大学学报

Obiective To explore the interaction of cefonicid sodium(CS) with bovine serum albumin(BSA) by fluorescence and absorption spectroscopy. Methods The rate constant(Kq), quenching constant(Ksv), static fluo-rescence quenching association constant(KLB),binding site number(n) and binding constant(Kb) were calculated using Stern-Volmer, Lineweaver-Burk and double logarithm equations. Results CS was able to bind to BSA. The probable quenching mechanism of BSA by CS was mainly static quenching due to the formation of a CS-BSA com-plex. The results of thermodynamic parameters indicated that electrostatic force plays the main role in the binding process and the binding process was spontaneous. There was a single class of binding site for the BSA with CS. The primary binding site for CS was located at sub-domainⅡA of BSA and near by tyrosine residue. There was almost some negative cooperative effect. The results obtained from synchronous fluorescence showed that CS could change the microenvironment of Tyrand Trp residues of BSA. Conclusion The interaction between CS and BSA is dynam-ic. There is a single class of binding site for the BSA with CS. The obtained results provide references for its clini-cal application.

Analysis of the interaction between cefdinir and bovine serum albumin by spectrometry / 中南大学学报(医学版)

OBJECTIVE@#To explore the interaction between cefdinir (CE) and bovine serum albumin (BSA) by fluorescence and ultraviolet-visible absorption spectrometry.
@*METHODS@#Under the optimal conditions, the interaction between CE and BSA was investigated by fluorescence and ultraviolet-visible absorption spectrometry.
@*RESULTS@#CE could quench (static quenching) the intrinsic fluorescence of BSA by forming the CE-BSA complex. The main binding forces were considered as hydrogen bonds and Van der Waals forces based on the calculated values of the thermodynamic parameter. The process of binding was spontaneous because Gibbs free energy change was negative. The primary binding site for CE was located at sub-domain II of BSA. The values of Hill's coefficients were less than 1, indicating a negative cooperative effect. Synchronous fluorescence spectra showed that the conjugation reaction between CE and BSA did not affect the conformation of BSA, and the binding site was close to the tyrosine residue.
@*CONCLUSION@#This test provides a theoretical basis for revealing the pharmacokinetic issue and the development for new drugs.

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

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.

Study on Interaction betweenYan-Hu-Ning and Bovine Serum Albumin by Spectrometry / 世界科学技术-中医药现代化

The interaction betweenYan-Hu-Ning (YHN) and bovine serum albumin (BSA) was investigated in order to provide further theoretical evidences on action mechanism study between YHN and proteins within the organism. Under optimal conditions, the interaction between YHN and BSA was studied by fluorescence quenching, ultraviolet absorption spectrometry and synchronous fluorescence spectroscopy. At the temperature of 283.15 K, 298.15 K and 313.15 K, quenching constant (KSV) and speed constant (Kq) were calculated by S-V curves. Static quenching constant (KLB) was obtained by L-B double reciprocal equation. Double logarithmic equation was used to calculate the binding constants (Kb) and the number of binding site (n). Thermodynamic equation was used to obtainΔH,ΔS,ΔG. Hill’s coefficients (nH) was obtained by Hill equation. The results showed that at three different temperatures, along with the increasing of YHN concentration, the fluorescence intensity of BSA decreased regularly. The value of KSV, Kq, KLB, Kb, n and nH decreased with the increasing of temperature;ΔG 1. It was concluded that YHN-BSA complex quenched the intrinsic fluorescence of BSA. The mechanism of fluorescence quenching was static quenching. The main binding forces were deduced as hydrogen bonds and Van der Waals forces from calculated values of thermodynamic parameters. YHN and BSA can form a binding site, which indicated certain binding interaction between YHN and BSA. YHN can be stored and transported by protein within the body. Free energy was produced to transformΔG into negative value. It showed that the process of binding between YHN and BSA was spontaneous. The nH was more than 1. It indicated that YHN had positive cooperative effect. The primary binding site was located at subdomainⅡA. The synchronous fluorescence spectra showed certain influence on the conformation of BSA by YHN. It led to the weakening of polarity within BSA and the binding site to be closer to the tyrosine.