头孢噻肟与人血清白蛋白的相互作用机制

Reaction Mechanism of Cefotaxime with Human Serum Albumin

用光谱技术研究人血清蛋白(HSA)与头孢噻肟(CTX)分子间结合作用机制,头孢噻肟与β-内酰胺酶的亲和力。由Lineweave-Burk双倒数作图法确定了该反应的解离常数Kd=1.22×10-4,用同步荧光技术考察头孢噻肟对人血清蛋白构象的影响。依据F rster非辐射能量转移机制,得到给体-受体间的结合距离和能量转移效率,确定了头孢噻肟与人血清白蛋白以疏水作用为主。认为头孢噻肟对β-内酰胺酶稳定性与药物结构有关;抗菌活性和抗生素效力与能量转移效率和解离常数有关。同步荧光技术考察头孢噻肟对人血清蛋白构象的影响。

The reaction mechanism of cefotaxime with human serum albumin （HSA） and the affinity between eefotaxime and β-laetamase were investigated by spectrometry and speetrofluorirnetry. The interaction dissociation constants of human serum albumin and eefotaxime were determined from a double reciprocal Lineweaver-Burk plot. The binding distance and transfer efficiency between eefotaxime and HSA were also obtained according to the theory of Foerster non-radiation energy transfer. The result suggested that the main binding force between eefotaxime and HSA is electrostatic force interaction. The high β-laetamase stability of eefotaxime may be correlative with its molecular structure. The antibiotic activity and valence are connected with transfer efficiency and dissociation constant. The effect of eefotaxime on the conformation of HSA was also analyzed using synchronous fluorescence spectrometry.