Functional Reconstitution of Olfactory Receptor for Analytical Application.

摘要

A model system was used to study the initial electrochemical membrane events in chemoreception by the mammalian olfactory epithelium: Membrane from rat olfactory epithelial homogenates incorporated into planar bimolecular lipid membranes and patch-bilayers. Data was obtained to support our hypothesis that the above described system in which we have demonstrated the presence of ion selective channels coupled with an activated enzyme cascade bears functional relationship to the initial chemoreceptive steps in olfaction. Chemosensitivity is manifested as a change in the mean open time of single channel events in response to small (subnanomolar) concentrations of the odorants in the medium bathing the membrane under control of the activity of cyclic nucleotide-processing enzymes. The kinetics of single channel events associated with the initial steps of olfaction have been studied. Involvement of guanine nucleotide-binding regulatory proteins (G-proteins), of second messenger (c-AMP), and protein kinases have been studied using voltage and patch-clamp techniques together with application of pharmacological agents known to alter the metabolism or effects of the second messenger. The study of the molecular mechanisms underlying the initial chemoreceptive events together with the development of stable reconstitution system should contribute toward the development of a practical analytical chemosensitive device. Keywords: Olfactory receptors; Enzymes; Proteins; Metabolism; Chemosensitive devices; Protein kinases. (kt)