title: Investigation on the interaction between a heterocyclic aminal derivative, SBDC, and human serum albumin.
abstract: The interaction between a novel promising drug (spiro[(2R,3R,4S)-4-benzyloxy-2,3-isopropylidene-dioxy-1-oxa-cyclopentane-5,5'-(2-benzoylmethylene-1,3-diaza-cyclohexane)] (SBDC)) and human serum albumin (HSA) under physiological conditions has been investigated by using fluorescence, absorption, and circular dichroism (CD) spectroscopic techniques in combination with protein-ligand docking study. It was observed that SBDC has a strong ability to quench the intrinsic fluorescence of HSA through a static quenching procedure. The association constants of SBDC with HSA were determined at different temperatures based on fluorescence quenching results. The negative DeltaH and positive DeltaS values in case of SBDC-HSA complex showed that apart from an initial hydrophobic association, both van der Waals interactions and hydrogen bonding play a vital role in the binding of SBDC to HSA. The quantitative analysis data of CD spectra showed that the binding of SBDC to HSA induced conformational changes in HSA and the alpha-helix of 52.1% in free HSA increased to 55.7% in HSA-SBDC complex. The distance between donor (HSA) and acceptor (SBDC) was obtained according to the Förster's theory of non-radiation energy transfer. Data obtained by spectroscopic techniques and protein-ligand docking study suggested that SBDC binds to residues located in subdomain IIA of HSA.
authors.affiliation: Beijing National Laboratory for Molecular Sciences (BNLMS), Center for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing, China.
authors.forename: Qiuju
authors.initials: Q
authors.lastname: Zhou
authors.forename: Junfeng
authors.initials: J
authors.lastname: Xiang
authors.forename: Yalin
authors.initials: Y
authors.lastname: Tang
authors.forename: Jiangpeng
authors.initials: J
authors.lastname: Liao
authors.forename: Chuyi
authors.initials: C
authors.lastname: Yu
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
authors.forename: Lin
authors.initials: L
authors.lastname: Li
authors.forename: Yueyang
authors.initials: Y
authors.lastname: Yang
authors.forename: Guangzhi
authors.initials: G
authors.lastname: Xu
mesh_terms: D000595:Amino Acid Sequence; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000737:chemistry*; D002942:Circular Dichroism; D006801:Humans; D008958:Models, Molecular; D011485:Protein Binding; D011743:Pyrimidines / Q000737:chemistry*; D012709:Serum Albumin / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D011743:Pyrimidines; D012709:Serum Albumin; C528414:spiro(4-benzyloxy-2,3-isopropylidenedioxy-1-oxa-cyclopentane-5,5'-(2-benzoylmethylene-1,3-diazacyclohexane))