title: Studies on the interaction between imidacloprid and human serum albumin: spectroscopic approach.
abstract: The interaction between imidacloprid (IMI) and human serum albumin (HSA) was investigated using fluorescence and UV/vis absorption spectroscopy. The experimental results showed that the fluorescence quenching of HSA by IMI was a result of the formation of IMI-HSA complex; static quenching was confirmed to result in the fluorescence quenching. The apparent binding constant K(A) between IMI and HSA at three differences were obtained to be 1.51 x 10(4), 1.58 x 10(4), and 2.19 x 10(4) L mol(-1), respectively. The thermodynamic parameters, DeltaH degrees and DeltaS degrees were estimated to be 28.44 kJ mol(-1), 174.76 J mol(-1) K(-1) according to the van't Hoff equation. Hydrophobic interactions played a major role in stabilizing the complex. The distance r between donor (HSA) and acceptor (IMI) was obtained according to fluorescence resonance energy transfer. The effect of IMI on the conformation of HSA was analyzed using synchronous fluorescence spectroscopy CD and three-dimensional fluorescence spectra, the environment around Trp and Tyr residues were altered.
authors.affiliation: Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, Yancheng City, Jiangsu Province 224002, People's Republic of China. wyqing76@126.com
authors.forename: Yan-qing
authors.initials: YQ
authors.lastname: Wang
authors.forename: Bo-ping
authors.initials: BP
authors.lastname: Tang
authors.forename: Hong-mei
authors.initials: HM
authors.lastname: Zhang
authors.forename: Qiu-hua
authors.initials: QH
authors.lastname: Zhou
authors.forename: Gen-cheng
authors.initials: GC
authors.lastname: Zhang
mesh_terms: D018678:Cholinergic Agents / Q000737:chemistry; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007093:Imidazoles / Q000737:chemistry*; D007306:Insecticides / Q000737:chemistry; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000737:chemistry*; D011487:Protein Conformation; D012709:Serum Albumin / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013057:Spectrum Analysis / Q000379:methods*; D013816:Thermodynamics
chemical_list: D018678:Cholinergic Agents; D007093:Imidazoles; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; D012709:Serum Albumin; C082359:imidacloprid