title: Mechanism of cinnamic acid-induced trypsin inhibition: a multi-technique approach.
abstract: In order to investigate the association of the protease trypsin with cinnamic acid, the interaction was characterized by using fluorescence, UV-vis absorption spectroscopy, molecular modeling and an enzymatic inhibition assay. The binding process may be outlined as follows: cinnamic acid can interact with trypsin with one binding site to form cinnamic acid-trypsin complex, resulting in inhibition of trypsin activity; the spectroscopic data show that the interaction is a spontaneous process with the estimated enthalpy and entropy changes being -8.95 kJ mol(-1) and 50.70 J mol(-1) K(-1), respectively. Noncovalent interactions make the main contribution to stabilize the trypsin-cinnamic acid complex; cinnamic acid can enter into the primary substrate-binding pocket and alter the environment around Trp and Tyr residues.
authors: Institute of Applied Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng City, Jiangsu Province 224002, People's Republic of China.
authors: Hongmei
authors: H
authors: Zhang
authors: Qiuhua
authors: Q
authors: Zhou
authors: Jian
authors: J
authors: Cao
authors: Yanqing
authors: Y
authors: Wang
mesh_terms: D000818:Animals; D001665:Binding Sites; D002934:Cinnamates / Q000494:pharmacology*; D008958:Models, Molecular; D011485:Protein Binding; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013552:Swine; D013816:Thermodynamics; D014357:Trypsin / Q000737:chemistry / Q000378:metabolism*; D014361:Trypsin Inhibitors / Q000494:pharmacology*
chemical_list: D002934:Cinnamates; D014361:Trypsin Inhibitors; C029010:cinnamic acid; D014357:Trypsin
keywords: Binding mode; Cinnamic acid; Inhibition; Molecular modeling; Trypsin