6-Chloropurine interactions with human serum albumin and itsapplication analysis

Abstract

The binding of 6-chloropurine (6-CP) with human serum albumin (HSA) was investigated by fluorescence spectroscopy and molecular modeling under simulated physiological conditions, which results showed that 6-CP formed a complex with HSA and strongly quenched the intrinsic fluorescence of HSA through static quenching. The change in enthalpy (Δ H ) and entropy (Δ S ) were calculated by the van’t Hoff equation. These data suggested that there were hydrogen bonds and van der Waals forces between 6-CP and HSA. These results agreed with those obtained by molecular modeling, which also showed hydrophobic interactions between HSA and 6-CP. The effect of 6-CP on the conformation of HSA was analyzed by three-dimensional fluorescence spectroscopy, and Warfarin and Ibuprofen were used as molecular probes to investigate the interaction sites of 6-CP and HSA. Under the optimum conditions, based on that the synchronous fluorescence intensity ( I SF) of the system was in direct proportion to the concentration of protein, the method of determining the protein used 6-CP as a fluorescence probe was applied with the detection limit 0.511 mg/L. And the amount of the proteins in human serum and saliva samples were detected and the recovery was 97.1%~101%. This method is simple, rapid, high sensitivity and could be used in biochemistry, clinical diagnosis or quality inspection.