title: Comparison and analysis on the serum-binding characteristics of aspirin-zinc complex and aspirin.
abstract: This study was designed to compare the protein-binding characteristics of aspirin-zinc complex (AZN) with those of aspirin itself. AZN was synthesized and interacted with a model transport protein, human serum albumin (HSA). Three-dimensional fluorescence, ultraviolet-visible and circular dichroism (CD) spectra were used to characterize the interaction of AZN with HSA under physiological conditions. The interaction mechanism was explored using a fluorescence quenching method and thermodynamic calculation. The binding site and binding locality of AZN on HSA were demonstrated using a fluorescence probe technique and Förster non-radiation energy transfer theory. Synchronous fluorescence and CD spectra were employed to reveal the effect of AZN on the native conformation of the protein. The HSA-binding results for AZN were compared with those for aspirin under consistent experimental conditions, and indicated that aspirin acts as a guide in AZN when binding to Sudlow's site I, in subdomain IIA of the HSA molecule. Moreover, compared with aspirin, AZN showed greater observed binding constants with, but smaller changes in the α-helicity of, HSA, which proved that AZN might be easier to transport and have less toxicity in vivo.
authors.affiliation: College of Chemical and Pharmaceutical Engineering, Jingchu University of Technology, Jingmen, People's Republic of China.
authors.forename: Hua-Xin
authors.initials: HX
authors.lastname: Zhang
authors.affiliation: College of Chemical and Pharmaceutical Engineering, Jingchu University of Technology, Jingmen, People's Republic of China.
authors.forename: Qun
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: College of Chemical and Pharmaceutical Engineering, Jingchu University of Technology, Jingmen, People's Republic of China.
authors.forename: Hong-Lin
authors.initials: HL
authors.lastname: Wang
authors.affiliation: College of Chemical and Pharmaceutical Engineering, Jingchu University of Technology, Jingmen, People's Republic of China.
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Li
mesh_terms: D001241:Aspirin / Q000737:chemistry*; D001665:Binding Sites; D002942:Circular Dichroism; D004735:Energy Transfer; D005453:Fluorescence; D006801:Humans; D006860:Hydrogen Bonding; D011485:Protein Binding; D012709:Serum Albumin / Q000737:chemistry*; D013816:Thermodynamics; D015032:Zinc / Q000737:chemistry*
chemical_list: D012709:Serum Albumin; D015032:Zinc; D001241:Aspirin
keywords: aspirin-zinc complex; circular dichroism; energy transfer; fluorescence; thermodynamics