Analysis on the interaction of coumarin isomers with human serum albumin in the presence of cisplatin

Abstract

Many drugs combined with human serum albumin (HSA) are commonly used for medical treatment. Various drugs can bind to HSA through hydrogen bonding and hydrophobic action, changing the binding affinity and binding mode between drugs and HSA and avoiding rapid drug metabolism. Through multispectral analysis and molecular docking simulation, the interaction between HSA and two coumarin isomers (pimpinellin and isopimpinellin) was analyzed and studied. Fluorescence quenching explained that regardless of cisplatin (cDDP), the amino acid residues of HSA could interact with pimpinellin and isopimpinellin. This interaction changed the inherent fluorescence intensity of HSA and formed the ground-state complexes through hydrogen bonding and hydrophobic interaction whether cDDP was present or not. Pimpinellin and isopimpinellin mainly bound to site I of the IIA subdomain in HSA, which could cause changes in the micro-environment surrounding amino acid residues. In addition, cDDP increased the conformational change during the interaction of HSA and pimpinellin/isopimpinellin. This work compared the interactive binding properties of pimpinellin/isopimpinellin with HSA in the presence of cDDP, which paved the way for the perfection of HSA as a drug delivery system in vivo.