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Anecdote:
A nameless colleague of mine once spent quite a bit of time optimizing a
crystal that only appeared in the presence of protein. Nothing showed
up in their no-protein control drops so they were confident this was a
protein crystal. The long and short of it was that their protein proved
to be an essential precipitation agent for salt.
-James Holton
MAD Scientist
Patrick Loll wrote:
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When attempting to crystallize the 1:1 complex of proteins A & B, we
get crystals that appear to contain A only, even though the
dissociation constant for A:B is quite low. This is not surprising
(albeit a tad annoying); the crystals grow at low pH and high salt,
so it's easy to understand how the complex might be disrupted.
However, B must be present, which I do find suprising; we only get
crystals when the mole ratio of A/B falls in the range 0.8-1.2.
I've heard of cases like this in the crystallization of
protein:nucleic acid complexes, but I'm not sure I've encountered one
for a protein:protein complex. Do others have similar anecdotes?
Thx,
Pat
------------------------------------------------------------------------
---------------
Patrick J. Loll, Ph. D. (215)
762-7706
Associate Professor FAX: (215) 762-4452
Department of Biochemistry & Molecular Biology
Director, Biochemistry Graduate Program
Drexel University College of Medicine
Room 10-102 New College Building
245 N. 15th St., Mailstop 497
Philadelphia, PA 19102-1192 USA
[EMAIL PROTECTED]
