Hi,
Many thanks to all who replied to my enquiry about the weakest protein-
protein complex crystallised. The idea that crystals themselves are
weak complexes had already crossed my mind and I was glad to hear it
confirmed by others. My impression is that there are no hard and fast
rules, and that crystallisation conditions can both work in favour of
and against the formation of complexes of many different affinities.
However one should certainly not be discouraged from trying to
crystallise complexes with Kd in the high uM or mM range. The one I
was considering has Kd around 25 uM. Thanks for all the literature
tips, which I will follow up (eventually).
One colleague, who naturally wishes to remain anonymous, suggested the
recent controversial C3b structure as a candidate for the weakest
complex yet crystallised. I think there was a play on words
involved ;-) But hey, let's not go *there* again...
Derek
__________________________________________________________________
Derek Logan tel: +46 46 222 1443
Molecular Biophysics fax: +46 46 222 4692
Centre for Molecular Protein Science mob: +46 76 8585 707
Lund University, Box 124, 221 00 Lund, Sweden