Non-covalent binding between tectoridin and plasma proteins by electrospray ion trap mass spectrometry / 中草药

ABSTRACT

Objective To study the non-covalent binding between the tectoridin(TE) and plasma proteins.Methods The molecular weights of TE,human serum albumin(HSA),?1-acid glycoprotein(AAG) and the protein-drug complexes were measured by the electrospray ion trap mass spectrometry(ESI-MS).The maximum stoichiometric ratios were obtained according to the molecular weight change of the complexes before and after binding reaction.The binding constants(K) of the complexes were calculated by the Scatchard equation.The main sorts of binding force of the complexes were deduced according to the relationship between the reaction temperature and the thermodynamic parameters(?H and ?S).Results The K of the complexes were 1.914?104 mol/L for TE-HSA and 5.893?104 mol/L for TE-AAG,and the number of binding sites were 7.8 and 3.3,respectively.The main sorts of binding force between TE-HSA or TE-AAG were static-electricity gravitation.Conclusion ESI-MS is a good method for studying of the TE-protein non-covalent binding with some advantages in sensitivity,high-speed,and accuracy.