title: Spectroscopic investigation and in vitro cytotoxic activity toward HepG2 cells of a copper compound complexed with human serum albumin.
abstract: The human serum albumin (HSA) interaction of a mixed-ligand copper compound (1) with an imidazole and taurine Schiff base derived from salicylaldehyde and taurine was investigated using fluorescence spectroscopy, UV-vis spectroscopy, time-resolved fluorescence spectroscopy, circular dichroism (CD) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and a molecular docking technique. The results of fluorescence and time-resolved fluorescence spectroscopy indicated that 1 can effectively quench the HSA fluorescence by a static mechanism. Binding constants (K) and the number of binding sites (n ≈ 1) were calculated using modified Stern-Volmer equations. The thermodynamic parameters were calculated. UV-vis, CD and FT-IR spectroscopy measurements confirm the alterations in the HSA secondary structure induced by 1. The site marker competitive experiment confirms that 1 is located in subdomain IB of HSA. The combination of molecular docking results and fluorescence experimental results reveal that hydrophobic interaction and hydrogen bonds are the predominant intermolecular forces stabilizing the 1-HSA complex. The 1-HSA complex increases approximately three times its cytotoxicity in cancer cells but has no effect on normal cells in vitro. Compared with unbound 1, the 1-HSA complex promotes HepG2 cells apoptosis and also has a stronger capacity for cell cycle arrest at the S phase of HepG2 cells.
authors.affiliation: Key Laboratory of Jiangxi University for Functional Material Chemistry, College of Chemistry and Chemical Engineering, Gannan Normal University, Ganzhou, Jiangxi, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Li
authors.affiliation: Key Laboratory of Jiangxi University for Functional Material Chemistry, College of Chemistry and Chemical Engineering, Gannan Normal University, Ganzhou, Jiangxi, China.
authors.forename: ShuJuan
authors.initials: S
authors.lastname: Huang
authors.affiliation: College of Mathematics and Computer Sciences, Gannan Normal University, Ganzhou, Jiangxi, China.
authors.forename: Qingyou
authors.initials: Q
authors.lastname: Cai
authors.affiliation: Key Laboratory of Jiangxi University for Functional Material Chemistry, College of Chemistry and Chemical Engineering, Gannan Normal University, Ganzhou, Jiangxi, China.
authors.forename: YongRong
authors.initials: Y
authors.lastname: Xie
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis; D002942:Circular Dichroism; D003300:Copper / Q000737:chemistry* / Q000494:pharmacology; D056945:Hep G2 Cells; D006801:Humans; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D007093:Imidazoles / Q000737:chemistry; D062105:Molecular Docking Simulation; D009942:Organometallic Compounds / Q000737:chemistry* / Q000494:pharmacology*; D017433:Protein Structure, Secondary; D012545:Schiff Bases / Q000737:chemistry; D000075462:Serum Albumin, Human / Q000737:chemistry* / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics
chemical_list: D000970:Antineoplastic Agents; D007093:Imidazoles; D009942:Organometallic Compounds; D012545:Schiff Bases; D003300:Copper; D000075462:Serum Albumin, Human
keywords: HSA; anticancer; copper compound; interaction