Help! How can I look at the conformational changes in proteins?
R. Bryan Sutton
sutton at howie.swmed.edu
Thu Mar 21 00:08:07 EST 1996
Please be VERY careful with this particular assay for conformational
change. Not only can a protease sensitive site be uncovered by a
structural change, but also a ligand-less protein CAN be more
"breathe-able" with respect to its liganded strucuture which can have a
more "solid" protease protected structure. Typsin can be very sneakey
if given the chance. This happened to us. Turns out that by X-ray
analysis and by NMR analysis, what was previously thought of as a
"structural change on ligand binding" was actually a firming up of the
fold of the protein. No residues actually changed position to any great
extend. The protease protection is probably a red herring in this case.
There are very well documented examples of protease protection revealing
gross structural changes. Just...PLEASE BE CAREFUL with the
interpretation of this assay.
More information about the Proteins