- Jean-Claude Bradley
I have just finished reading the fascinating book “The Emperor of Scent” by Chandler Burr. It starts off describing the world of perfume with a focus on Luca Turin, a man with the unusual talent of being able to review perfumes with great eloquence, conjuring up beautiful metaphors of experiencing their scent.
The book then takes an unexpected turn into the description of Turin’s theory about the mechanism of olfaction. There is some truly interesting science there, such as Turin’s discovery of a binding site for NADPH and another for zinc on a protein thought to mediate smell. This supports his hypothesis that the protein functions as an electron tunneling spectroscope detecting differences in vibrational modes. Further evidence is provided by comparing the different smells of deuterated molecules like acetophenone and the similarity of the stench of boranes with thiols, which share similar IR spectral bands. This idea is at odds with the conventional view that molecular shape is responsible for the activity of odorants. (For a summary of Turin’s theory I would suggest watching his recent TED talk “The Science of Scent” and his Wikipedia entry).