3D-proteine structure: Homology modeling versus X-ray chrystallography

[Lynn TenEyck]

crebeiz at UIUC.EDU (C. Rebeiz) wrote:
> . . . I wonder
> however, about the relationship of a laboratory-grown crystal of a
> membrane-bound solubilized protein to the native protein in situ. 
> Constantin A. Rebeiz
> 240 A, PABL
> 1201 W. Gregory
> Univ. Illinois, Urbana, IL 61801
> 
True, many of us do -- but at least we know the real fold of that 
polypeptide under at least one set of conditions.

It is often not mentioned that the "folding problem" is actually the
prediction of the structure of a particular sequence in a particular
                                                     ^^^^^^^^^^^^^^^
environment.  If this were not so, proteins would not denature, and
^^^^^^^^^^^
we know that some of them are very sensitive to things like pH,
temperature, salt, . . . 

This makes the "folding problem" something more than an exercise in
pattern detection and matching.

Lynn Ten Eyck
teneyck at sdsc.edu