Binding of nicotine to Gastrin I Human studied by fluorescence spectroscopy and nuclear magnetic resonance methods

The interaction between nicotine and Gastrin I Human (GIH) was studied by fluorescence spectroscopy and nuclear magnetic resonance(NMR)methods. Nicotine had little influence on GIH when the ratio of nicotine and GIH was below 80:1. However, with an increasing nicotine concentration, nicotine gradually quenched the intrinsic GIH. NMR showed that nicotine interacted with GIH and the pyrrolidyl ring of nicotine was the major binding function. Hydrogen bonding and van der Waals forces were the major functions in the binding between nicotine and GIH. 3D and synchronous fluorescence studies indicated that GIH emission was primarily attributed to the Trp residues. The results obtained from the present work may be useful to understand the role of nicotine in developing smokeless tobacco products.