title: Studies on the interaction of salvianolic acid B with human hemoglobin by multi-spectroscopic techniques.
abstract: The interaction between salvianolic acid B (Sal B) and human hemoglobin (HHb) under physiological conditions was investigated by UV-vis absorption, fluorescence, synchronous fluorescence and circular dichroism spectroscopic techniques. The experimental results indicate that the quenching mechanism of fluorescence of HHb by Sal B is a static quenching procedure, the binding reaction is spontaneous, and the hydrophobic interactions play a major role in binding of Sal B to HHb. Based on Förster's theory of non-radiative energy transfer, the binding distance between Sal B and the inner tryptophan residues of HHb was determined to be 2.64 nm. The synchronous fluorescence experiment revealed that Sal B can not lead to the microenvironmental changes around the Tyr and Trp residues of HHb, and the binding site of Sal B on HHb is located at α(1)β(2) interface of HHb. Furthermore, the CD spectroscopy indicated the secondary structure of HHb is not changed in the presence of Sal B.
authors.affiliation: School of Chemistry and Chemical Engineering, Nantong University, Nantong, PR China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Chen
authors.forename: Shajun
authors.initials: S
authors.lastname: Zhu
authors.forename: Hui
authors.initials: H
authors.lastname: Cao
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Shang
authors.forename: Miao
authors.initials: M
authors.lastname: Wang
authors.forename: Guoqing
authors.initials: G
authors.lastname: Jiang
authors.forename: Yujun
authors.initials: Y
authors.lastname: Shi
authors.forename: Tianhong
authors.initials: T
authors.lastname: Lu
mesh_terms: D001572:Benzofurans / Q000737:chemistry* / Q000378:metabolism; D002942:Circular Dichroism; D004365:Drugs, Chinese Herbal / Q000737:chemistry; D006454:Hemoglobins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D015394:Molecular Structure; D013057:Spectrum Analysis / Q000379:methods*; D014443:Tyrosine / Q000737:chemistry; D053630:Depsides
chemical_list: D001572:Benzofurans; D004365:Drugs, Chinese Herbal; D006454:Hemoglobins; D014443:Tyrosine; C076944:salvianolic acid B; D053630:Depsides