Methionine oxidation/chromatography/crosslinking

Paul Tressel (pault@allelix.com)
Fri, 15 Jan 1999 11:21:41 -0500

HPLC anion exchange separates native from methionine sulfoxide versions
or our 33 amino acid peptide (sulfoxide elutes first). This suggests a
decrease in pI upon oxidation. I can not find a reference to support
this, however, and I couldn't calculate the new pI with Swiss Pro. Does
anyone know a good reference or calculation site that might help?

I would also like to make a chemical dimer of my peptide (without higher
multimers). The only reactive singlet amino acids (aside from the
termini) are histidine and methionine. I've checked with Pierce
technical service, but no luck yet on a specific reagent. Any ideas?

Thanks, Paul Tressel