title: Interaction studies of aristolochic acid I with human serum albumin and the binding site of aristolochic acid I in subdomain IIA.
abstract: Optical spectroscopy and molecular docking methods were used to examine the binding of aristolochic acid I (AAI) to human serum albumin (HSA) in this paper. By monitoring the intrinsic fluorescence of single Trp214 residue and performing displacement measurements, the specific binding of AAI in the vicinity of Sudlow's Site I of HSA has been clarified. An apparent distance of 2.53nm between the Trp214 and AAI was obtained via fluorescence resonance energy transfer (FRET) method. In addition, the changes in the secondary structure of HSA after its complexation with the ligand were studied with circular dichroism (CD) spectroscopy, which indicated that AAI does not has remarkable effect on the structure of the protein. Moreover, thermal denaturation experiments clearly indicated that the HSA-AAI complexes are conformationally more stable. Finally, the binding details between AAI and HSA were further confirmed by molecular docking studies, which revealed that AAI was bound at subdomain IIA through multiple interactions, such as hydrophobic effect, van der Waals forces and hydrogen bonding.
authors.affiliation: College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, People's Republic of China.
authors.forename: Xinhu
authors.initials: X
authors.lastname: Wu
authors.forename: Jianjun
authors.initials: J
authors.lastname: Liu
authors.forename: Hanming
authors.initials: H
authors.lastname: Huang
authors.forename: Weiwei
authors.initials: W
authors.lastname: Xue
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Yao
authors.forename: Jing
authors.initials: J
authors.lastname: Jin
mesh_terms: D034341:Aristolochic Acids / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D001665:Binding Sites; D002942:Circular Dichroism; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D008958:Models, Molecular; D011485:Protein Binding; D017433:Protein Structure, Secondary / Q000187:drug effects; D017434:Protein Structure, Tertiary; D012709:Serum Albumin / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D034341:Aristolochic Acids; D012709:Serum Albumin; C000228:aristolochic acid I