title: Human serum albumin stability and toxicity of anthraquinone dye alizarin complexone: an albumin-dye model.
abstract: The complexation between the primary vector of ligands in blood plasma, human serum albumin (HSA) and a toxic anthraquinone dye alizarin complexone, was unmasked by means of circular dichroism (CD), molecular modeling, steady state and time-resolved fluorescence, and UV/vis absorption measurements. The structural investigation of the complexed HSA through far-UV CD, three-dimensional and synchronous fluorescence shown the polypeptide chain of HSA partially destabilizing with a reduction of α-helix upon conjugation. From molecular modeling and competitive ligand binding results, Sudlow's site I, which was the same as that of warfarin-azapropazone site, was appointed to retain high-affinity for alizarin complexone. Moreover, steady state fluorescence displayed that static type and Förster energy transfer is the operational mechanism for the vanish in the tryptophan (Trp)-214 fluorescence, this corroborates time-resolved fluorescence that HSA-alizarin complexone adduct formation has an affinity of 10(5) M(-1), and the driving forces were found to be chiefly π-π, hydrophobic, and hydrogen bonds, associated with an exothermic free energy change. These data should be utilized to illustrate the mechanism by which the toxicological action of anthraquinone dyes is mitigated by transporter HSA.
authors.affiliation: Department of Chemistry, China Agricultural University, Beijing 100193, China; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors.forename: Fei
authors.initials: F
authors.lastname: Ding
authors.affiliation: Key Laboratory of Pesticide Chemistry and Application Technology, Ministry of Agriculture, Department of Applied Chemistry, China Agricultural University, Beijing 100193, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Jian-Xiong
authors.initials: JX
authors.lastname: Diao
authors.affiliation: National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Xiu-Nan
authors.initials: XN
authors.lastname: Li
authors.affiliation: School of Environment, Tsinghua University, Beijing 100084, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Ma
authors.affiliation: College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China. Electronic address: sunying@cau.edu.cn.
authors.forename: Ying
authors.initials: Y
authors.lastname: Sun
mesh_terms: D000880:Anthraquinones / Q000737:chemistry / Q000633:toxicity*; D004396:Coloring Agents / Q000737:chemistry / Q000633:toxicity*; D006801:Humans; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D008956:Models, Chemical; D056004:Molecular Dynamics Simulation; D012709:Serum Albumin / Q000737:chemistry*
chemical_list: D000880:Anthraquinones; D004396:Coloring Agents; D012709:Serum Albumin; C070804:alizarin complexone