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Hi Artem,
Loss of fluorescence and similar phenomena under a laser in light
microscopy are commonly used tools in cell biology (FLIM-FRET), for
example to investigate the turnover of proteins in particular cellular
locations (you bleach a region and then watch the fluorescence become
reestablished).
A web search for FLIM-FRET might lead you to some relevant info,
althought probably not specifically with X-rays.
Cheers,
Charlie
Artem Evdokimov wrote:
Hello fellow ccp4-ers,
Here’s a somewhat unrelated question J
We’ve recently solved a structure of a green fluorescent protein from a
marine copepod /Pontellina plumata/ (PDBIDs 2G6X, 2G6Y – already
released to the public), and are in the process of publishing the
results. While I was collecting data (100K), I have noticed a peculiar
phenomenon: during the very first X-ray exposure, the normally intensely
greenish-yellow color of the crystals completely disappeared within the
area that was hit by the beam. That was happening in real time, while
the crystal was still frozen. There was no significant deterioration of
diffraction quality, and the structures were successfully solved using
these data. We noted no anomalies in the chromophore as such – it looks
like a typical GFP heterocycle, although the resolution isn’t sufficient
to refine w/o restraints and thus verify the exact bond types etc.
Here’s the question – does anyone know of a published report of this
phenomenon, as related to other GFPs, or other colored/fluorescent
beta-barrel proteins? We couldn’t find any, but that doesn’t mean that
there wasn’t a mention in one of the dozens of GFP structural papers.
Thank you,
Artem
[EMAIL PROTECTED]
ex-PGP
--
Dr Charles S. Bond University of Dundee Tel: +44-1382-388325
Honorary Lecturer Dow St, Dundee Fax: +44-1382-345764
BBSRC David Phillips Fellow DD1 5EH, Scotland [EMAIL PROTECTED]
School of Life Sciences http://stein.bioch.dundee.ac.uk/~charlie
