title: Exploration of binding of C.I. Food Red 9 with pepsin by optical spectroscopic and molecular docking methods.
abstract: A comprehensive study of the effects of C.I. Food Red 9 on the conformation and activity of pepsin was performed using multi-spectral methods and molecular docking technique. Fluorescence and circular dichroism spectral analyzes showed that C.I. Food Red 9 binding induced the changes of secondary and tertiary structure of pepsin. The activity experimental results indicated that the activity of pepsin decreased remarkably with the increasing concentration of C.I. Food Red 9. Multi non-covalent interactions including hydrogen bonds, hydrophobic, and electrostatic forces played important roles in the complex formation between C.I. Food Red 9 and pepsin. The binding constants of pepsin with C.I. Food Red 9 were (1.21±0.036)×10(4) L mol(-1) (298 K) and (1.05±0.043)×10(4) L mol(-1) (310 K). Moreover, the putative binding site of C.I. Food Red 9 on pepsin was near to activity pocket. This study demonstrates that C.I. Food Red 9 could cause some negative effects on pepsin.
authors.affiliation: Institute of Applied Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng City, Jiangsu Province 224002, People's Republic of China. Electronic address: wyqing76@126.com.
authors.forename: Yan-Qing
authors.initials: YQ
authors.lastname: Wang
authors.affiliation: Institute of Applied Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng City, Jiangsu Province 224002, People's Republic of China.
authors.forename: Hong-Mei
authors.initials: HM
authors.lastname: Zhang
mesh_terms: D000548:Amaranth Dye / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D001391:Azo Compounds / Q000737:chemistry / Q000378:metabolism*; D004583:Electrons; D007700:Kinetics; D062105:Molecular Docking Simulation; D055620:Optical Phenomena; D010434:Pepsin A / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D034421:Sus scrofa; D013696:Temperature
chemical_list: D001391:Azo Compounds; D000548:Amaranth Dye; D010434:Pepsin A
keywords: Activity; Binding interaction; C.I. Food Red 9; Pepsin