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Science is perception: what can our sense of smell tell us about ourselves and the world around us?

Brookes JC - Philos Trans A Math Phys Eng Sci (2010)

Bottom Line: These fundamental questions are not answered within the sphere of smell science; we do not know what it is about a molecule that ... smells.Most importantly, I draw links and comparisons as to how better understanding of how small (10's of atoms) molecules can interact so specially with large (10,000's of atoms) proteins in a way that is so integral to healthy living.Repercussions of this work are not just important in understanding a basic scientific tool used by us all, but often taken for granted, it is also a step closer to understanding generic mechanisms between drug and receptor, for example.

View Article: PubMed Central - PubMed

Affiliation: The London Centre for Nanotechnology, University College London, Gower Street, London WC1E 6BT, UK. ucapjcb@ucl.ac.uk

ABSTRACT
Human sensory processes are well understood: hearing, seeing, perhaps even tasting and touch--but we do not understand smell--the elusive sense. That is, for the others we know what stimuli causes what response, and why and how. These fundamental questions are not answered within the sphere of smell science; we do not know what it is about a molecule that ... smells. I report, here, the status quo theories for olfaction, highlighting what we do not know, and explaining why dismissing the perception of the input as 'too subjective' acts as a roadblock not conducive to scientific inquiry. I outline the current and new theory that conjectures a mechanism for signal transduction based on quantum mechanical phenomena, dubbed the 'swipe card', which is perhaps controversial but feasible. I show that such lines of thinking may answer some questions, or at least pose the right questions. Most importantly, I draw links and comparisons as to how better understanding of how small (10's of atoms) molecules can interact so specially with large (10,000's of atoms) proteins in a way that is so integral to healthy living. Repercussions of this work are not just important in understanding a basic scientific tool used by us all, but often taken for granted, it is also a step closer to understanding generic mechanisms between drug and receptor, for example.

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Related in: MedlinePlus

The proposed sequence of events according to Turin’s theory of signal transduction is shown. The olfactory receptor is pictured here as a cartoon with five cylinders to represent the protein helices (there are typically seven); the odorant is a carborane isomer—a camphoraceous smelling molecule (Turin & Yoshii 2003). (a) Source of electrons available at RD. (b) Electron tunnels to site D (donor) as odorant docks and deforms receptor. (c) Electron tunnels to A (acceptor) mediated by odorant phonon. (d) Odorant is expelled and electron transmission to RA initiates signal.
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RSTA20100117F2: The proposed sequence of events according to Turin’s theory of signal transduction is shown. The olfactory receptor is pictured here as a cartoon with five cylinders to represent the protein helices (there are typically seven); the odorant is a carborane isomer—a camphoraceous smelling molecule (Turin & Yoshii 2003). (a) Source of electrons available at RD. (b) Electron tunnels to site D (donor) as odorant docks and deforms receptor. (c) Electron tunnels to A (acceptor) mediated by odorant phonon. (d) Odorant is expelled and electron transmission to RA initiates signal.

Mentions: Turin (1996) proposed a theory to include quantum mechanics in our understanding of smell. He postulated that the olfactory receptor contains electron donor (D) and electron acceptor (A) units which are separated in energy by a fixed amount that matches a specific odorant’s quanta of vibration (a phonon). Upon an odorant binding to its receptor, an electron tunnelling event occurs when the emitted phonon fills this D–A gap, which in turn may initiate the transmission step towards the brain. Once the electron reaches A, the signal is initiated via the G-protein release mechanism. The D and A are electron sources and sinks, respectively, as part of the receptor protein which provides the tunnelling electron which is the message carrier (figure 2).


Science is perception: what can our sense of smell tell us about ourselves and the world around us?

Brookes JC - Philos Trans A Math Phys Eng Sci (2010)

The proposed sequence of events according to Turin’s theory of signal transduction is shown. The olfactory receptor is pictured here as a cartoon with five cylinders to represent the protein helices (there are typically seven); the odorant is a carborane isomer—a camphoraceous smelling molecule (Turin & Yoshii 2003). (a) Source of electrons available at RD. (b) Electron tunnels to site D (donor) as odorant docks and deforms receptor. (c) Electron tunnels to A (acceptor) mediated by odorant phonon. (d) Odorant is expelled and electron transmission to RA initiates signal.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2944383&req=5

RSTA20100117F2: The proposed sequence of events according to Turin’s theory of signal transduction is shown. The olfactory receptor is pictured here as a cartoon with five cylinders to represent the protein helices (there are typically seven); the odorant is a carborane isomer—a camphoraceous smelling molecule (Turin & Yoshii 2003). (a) Source of electrons available at RD. (b) Electron tunnels to site D (donor) as odorant docks and deforms receptor. (c) Electron tunnels to A (acceptor) mediated by odorant phonon. (d) Odorant is expelled and electron transmission to RA initiates signal.
Mentions: Turin (1996) proposed a theory to include quantum mechanics in our understanding of smell. He postulated that the olfactory receptor contains electron donor (D) and electron acceptor (A) units which are separated in energy by a fixed amount that matches a specific odorant’s quanta of vibration (a phonon). Upon an odorant binding to its receptor, an electron tunnelling event occurs when the emitted phonon fills this D–A gap, which in turn may initiate the transmission step towards the brain. Once the electron reaches A, the signal is initiated via the G-protein release mechanism. The D and A are electron sources and sinks, respectively, as part of the receptor protein which provides the tunnelling electron which is the message carrier (figure 2).

Bottom Line: These fundamental questions are not answered within the sphere of smell science; we do not know what it is about a molecule that ... smells.Most importantly, I draw links and comparisons as to how better understanding of how small (10's of atoms) molecules can interact so specially with large (10,000's of atoms) proteins in a way that is so integral to healthy living.Repercussions of this work are not just important in understanding a basic scientific tool used by us all, but often taken for granted, it is also a step closer to understanding generic mechanisms between drug and receptor, for example.

View Article: PubMed Central - PubMed

Affiliation: The London Centre for Nanotechnology, University College London, Gower Street, London WC1E 6BT, UK. ucapjcb@ucl.ac.uk

ABSTRACT
Human sensory processes are well understood: hearing, seeing, perhaps even tasting and touch--but we do not understand smell--the elusive sense. That is, for the others we know what stimuli causes what response, and why and how. These fundamental questions are not answered within the sphere of smell science; we do not know what it is about a molecule that ... smells. I report, here, the status quo theories for olfaction, highlighting what we do not know, and explaining why dismissing the perception of the input as 'too subjective' acts as a roadblock not conducive to scientific inquiry. I outline the current and new theory that conjectures a mechanism for signal transduction based on quantum mechanical phenomena, dubbed the 'swipe card', which is perhaps controversial but feasible. I show that such lines of thinking may answer some questions, or at least pose the right questions. Most importantly, I draw links and comparisons as to how better understanding of how small (10's of atoms) molecules can interact so specially with large (10,000's of atoms) proteins in a way that is so integral to healthy living. Repercussions of this work are not just important in understanding a basic scientific tool used by us all, but often taken for granted, it is also a step closer to understanding generic mechanisms between drug and receptor, for example.

Show MeSH
Related in: MedlinePlus