Quantum origins of molecular recognition and olfaction in Drosophila.

@article{Bittner2012QuantumOO,
  title={Quantum origins of molecular recognition and olfaction in Drosophila.},
  author={Eric R. Bittner and Adrian Madalan and Arkadiusz Czader and Gregg Roman},
  journal={The Journal of chemical physics},
  year={2012},
  volume={137 22},
  pages={
          22A551
        }
}
The standard model for molecular recognition of an odorant is that receptor sites discriminate by molecular geometry as evidenced that two chiral molecules may smell very differently. However, recent studies of isotopically labeled olfactants indicate that there may be a molecular vibration-sensing component to olfactory reception, specifically in the spectral region around 2300 cm(-1). Here, we present a donor-bridge-acceptor model for olfaction which attempts to explain this effect. Our model… 

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References

SHOWING 1-10 OF 34 REFERENCES

Molecular vibration-sensing component in Drosophila melanogaster olfaction

It is reported that flies not only differentiate between isotopic odorants, but can be conditioned to selectively avoid the common or the deuterated isotope, which supports the existence of a molecular vibration-sensing component to olfactory reception.

A spectroscopic mechanism for primary olfactory reception.

The evidence presented here suggests that olfaction, like colour vision and hearing, is a spectral sense, and that inelastic electron tunnelling is the mechanism for biological transduction of molecular vibrations.

Could humans recognize odor by phonon assisted tunneling?

A novel proposal suggests receptors are actuated by inelastic electron tunneling from a donor to an acceptor mediated by the odorant, and provides critical discrimination, and is tested using the swipe card model.

Is the olfactory receptor a metalloprotein?

A hypothesis in which metal ions play an important role for odorant recognition is described and a “shuttlecock” mechanism for the possible structural change in ORs upon odorant binding is proposed, involving membrane penetration of the 4–5 loop after residue charge neutralization by metal ion binding.

A method for the calculation of odor character from molecular structure.

  • L. Turin
  • Chemistry
    Journal of theoretical biology
  • 2002
This work takes up and extended an old idea according to which vertebrate olfactory receptors detect odorants by their molecular vibrations, and proposes that the detection mechanism is inelastic electron tunnelling, and calculates the spectra of structurally diverse odorants belonging to various odor categories.

Olfaction is a chemical sense, not a spectral sense

The discrimination of normal and deuterated odorants by flies is a clear and convincing finding, but such isotope effects do not prove that the animals are sensing infrared molecular vibrations using inelastic electron tunneling spectroscopy (IETS).

Electron transfer : from isolated molecules to biomolecules

Electron Transfer Past and Future (R. Marcus). Electron Transfer Reactions in Solution: A Historical Perspective (N. Sutin). Electron Transfer--From Isolated Molecules to Biomolecules (M. Bixon & J.

Inelastic tunneling in long-distance biological electron transfer reactions

The effect of protein dynamics on the long-distance biological electron transfer reactions is discussed. Computer simulations reported recently by our group [Daizadeh, Medvedev, and Stuchebrukhov,

Classical conditioning and retention in normal and mutantDrosophila melanogaster

By changing the conditioned discrimination paradigm of Quinn et al. (1974) from an instrumental procedure to a classical (Pavlovian) one, strong learning in type flies is demonstrated and conditioned avoidance still was measurable at least three hours after training.