[ccp4bb]: re Semet from David Borani

["Bernhard Rupp" <br@llnl.gov>]

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I am having trouble posting to the BB;
Bernard, perhaps you could forward this

I don't understand the rather cavalier attitude towards Se-Met oxidation.
For
one of the proteins I worked on, Apo A-I, oxidation of the (sulfur)
methionines
DRAMATICALLY alters the physicochemical and biological properties of the
protein. The reason is obvious....Met is a hydrophobic side chain; oxidized
Met
is VERY hydrophilic (it is basically like the universal solvent DMSO) and
has a
strong, permanent dipole moment.

I would imagine that the properties of most proteins would be altered if you
suddenly stuck a (delta+)Se--O(delta-) bond in the middle of the hydrophobic
core. I think care to prevent Se-Met oxidation is called for.

David Borhani
Abbott Bioresearch Center
Worcester MA 01605
508-849-2944
borhand@basf.com