title: The interaction of C.I. acid red 27 with human hemoglobin in solution.
abstract: The nature of the interaction between human hemoglobin and C.I. acid red 27 was investigated systematically by ultraviolet-vis absorbance, circular dichroism, fluorescence, synchronous fluorescence, and three-dimensional fluorescence spectra techniques at pH 7.40. The quenching mechanism, binding constants, and the number of binding sites were determined by the quenching of human hemoglobin fluorescence in presence of C.I. acid red 27. The results showed that the nature of the quenching was of static type and the process of binding acid red 27 on human hemoglobin was a spontaneous molecular interaction procedure. The electrostatic and hydrophobic interactions played a major role in stabilizing the complex; The distance r between donor and acceptor was obtained to be 4.40 nm according to Förster's theory; The effect of acid red 27 on the conformation of human hemoglobin was analyzed using synchronous fluorescence, circular dichroism and three-dimensional fluorescence spectra.
authors.affiliation: Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, Yancheng City, Jiangsu Province, People's Republic of China. wyqing76@126.com
authors.forename: Yan-Qing
authors.initials: YQ
authors.lastname: Wang
authors.forename: Hong-Mei
authors.initials: HM
authors.lastname: Zhang
authors.forename: Bo-Ping
authors.initials: BP
authors.lastname: Tang
mesh_terms: D000548:Amaranth Dye; D001391:Azo Compounds / Q000737:chemistry*; D001665:Binding Sites; D002942:Circular Dichroism; D004396:Coloring Agents / Q000737:chemistry*; D004735:Energy Transfer; D006454:Hemoglobins / Q000737:chemistry*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D011485:Protein Binding; D012996:Solutions; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D055672:Static Electricity
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D006454:Hemoglobins; D012996:Solutions; D000548:Amaranth Dye