title: Study on the interaction between histidine-capped Au nanoclusters and bovine serum albumin with spectroscopic techniques.
abstract: The understanding of the protein-nanoclusters interaction has significant implications for biological applications of nanoclusters (NCs). In this manuscript, the interaction of histidine-capped Au nanoclusters (NCs) with bovine serum albumin (BSA) has been investigated by fluorescence, UV-vis, circular dichroism (CD) and Raman spectroscopic techniques under simulative physiological conditions. The results showed that the fluorescence of BSA was quenched by Au NCs. The quenching mechanism was discussed to be a dynamic quenching style, which was proved by the fluorescence spectra and UV-vis absorption spectra. According to modified Stern-Volmer equations at different temperatures, corresponding thermodynamic parameters, ΔH(θ), ΔS(θ) and ΔG(θ) were observed to be 35.97 kJ mol(-1), 199.53 J mol(-1) K(-1) and -23.49 kJ mol(-1), respectively. The hydrophobic force played a key role in the interaction process. Further results from the CD spectra and Raman spectra demonstrated that the α-helical content in BSA was reduced upon interaction with Au NCs which induced a partial protein destabilization. This study contributes to a better understanding of the biology toxicity of Au NCs to biomolecular, which is very essential for the development of safe and functional Au NCs.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, College of Science, Institute of Chemical Biology, Huazhong Agricultural University, Wuhan 430070, PR China.
authors.forename: Chengzhi
authors.initials: C
authors.lastname: Zheng
authors.forename: Huiping
authors.initials: H
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.forename: Chaoyong
authors.initials: C
authors.lastname: Xu
authors.forename: Jiangong
authors.initials: J
authors.lastname: Liang
authors.forename: Heyou
authors.initials: H
authors.lastname: Han
mesh_terms: D000818:Animals; D002417:Cattle; D005453:Fluorescence; D006046:Gold / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D049329:Nanostructures / Q000737:chemistry*; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013050:Spectrometry, Fluorescence
chemical_list: D012710:Serum Albumin, Bovine; D006639:Histidine; D006046:Gold
keywords: Au nanoclusters; Bovine serum albumin; Fluorescence; Interaction; Quenching