Investigations on the binding of human hemoglobin with orange I and orange II.
The interactions between human hemoglobin and orange I (or orange II) were investigated by UV/vis absorption, circular dichroism, fluorescence spectra techniques, and molecular modeling method. Orange I and orange II effectively quenched the intrinsic fluorescence of human hemoglobin by static quenching. The processes of the binding orange I and orange II on human hemoglobin were spontaneous molecular interaction procedure with hydrogen bonds, van der Waals force, hydrophobic and electrostatic interactions according to van't Hoff equation and molecular modeling. There is a single class of binding site of orange I (orange II) in human hemoglobin and the molecular modeling study shows that orange I and orange II are dipped into α(2) chain. The results of CD, synchronous fluorescence and three-dimensional fluorescence spectra indicated a small loss of α-helical secondary structure of human hemoglobin induced by orange I and orange II.
Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, Institute of Applied Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng City, Jiangsu Province 224002, People's Republic of China. wyqing76@126.com
Yan-Qing
YQ
Wang
Hong-Mei
HM
Zhang
D001391:Azo Compounds / Q000737:chemistry*; D001557:Benzenesulfonates / Q000737:chemistry*; D001665:Binding Sites; D002942:Circular Dichroism; D006454:Hemoglobins / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008958:Models, Molecular; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D013056:Spectrophotometry, Ultraviolet
D001391:Azo Compounds; D001557:Benzenesulfonates; D006454:Hemoglobins; C022808:E 111; C014722:2-naphthol orange