Hi All, I was wondering if anyone knew whether or not it is possible for reducing agents with thiol groups, such as DTT or beta-mercaptoethanol (BME), to form covalent S-S bonds with Cys residues, particularly solvent-exposed Cys? I have some puzzling biochemical results, and in the absence of a structure (thus far), I was wondering if this might be something to try to control for. I have never heard of this happening (or seen a structure where there was density for this type of adduct), but I can't really think of a good reason for why this wouldn't happen. Especially for something like BME, where the molecule is very much like the Cys sidechain and seems to me like it should have similar reactivity. The only thing I can think of is if there is a kinetic effect taking place. Perhaps the rate of diffusion of these small molecules is much faster that the formation of the S-S bond?
Does anyone know whether or not this is possible, and why it does or does not happen? Thanks, Mike -- Michael C. Thompson Graduate Student Biochemistry & Molecular Biology Division Department of Chemistry & Biochemistry University of California, Los Angeles mi...@chem.ucla.edu
