Ilia A. Solov'yov, Po-Yao Chang, and Klaus Schulten.
Vibrationally assisted electron transfer mechanism of olfaction: Myth
or reality?
Physical Chemistry - Chemical Physics, 14:13861-13871, 2012.
(PMC: 3478898)
SOLO2012B
Smell is a vital sense for animals. The mainstream explanation of smell is based on
recognition of the odorant molecules through characteristics of their surface, e.g., shape,
but certain experiments suggest that such recognition is complemented by recognition of
vibrational modes. According to this suggestion an olfactory receptor is activated by
electron transfer assisted through odorant vibrational excitation. The hundreds to
thousands of different olfactory receptors in an animal recognize odorants over a
discriminant landscape with surface properties and vibrational spectrum as the two major
dimensions. In the present paper we introduce the vibrationally assisted mechanism of
olfaction and demonstrate for several odorants that, indeed, a strong enhancement of an
electron tunneling rate due to operant vibrations can arise. We discuss in this regard the
influence of odorant deuteration and explain, thereby, recent experiments performed on
Drosophila melanogaster. Our demonstration is based on known physical properties of
biological electron transfer and on ab initio calculations on odorants carried out for the
purpose of the present study. We identify a range of physical characteristics which
olfactory receptors and odorants must obey for the vibrationally assisted electron transfer
mechanism to function. We argue that the stated characteristics are feasible for realistic
olfactory receptors, noting, though, that the receptor structure presently is still unknown,
but had been studied through homology modeling.
Download Full Text
The manuscripts available on our site are provided for your personal
use only and may not be retransmitted or redistributed without written
permissions from the paper's publisher and author. You may not upload any
of this site's material to any public server, on-line service, network, or
bulletin board without prior written permission from the publisher and
author. You may not make copies for any commercial purpose. Reproduction
or storage of materials retrieved from this web site is subject to the
U.S. Copyright Act of 1976, Title 17 U.S.C.
