This probably gives you more possibilities than you hoped for!
Leo Benoiton
benoiton@aix1.uottawa.ca
On Fri, 12 Sep 1997 RLNiece@AOL.com wrote:
~~e of our user groups brought us a sample of carbodiimide cross-linked
roteins (A and B, both sequences known) that had then been subsequently
> One of our user groups brought us a sample of carbodiimide cross-linked
> proteins (A and B, both sequences known) that had then been subsequently
> reduced, alkylated and digested with trypsin. The mass of one of the HPLC
> peaks indicated it could contain cross-linked peptides from proteins A and B
> so we chose to sequence this fraction. In each cycle we saw residues that
> fit a peptide from protein A and residues that fit a peptide from protein B.
> That was nice. However, while both peptides had several acidic residues,
> neither peptide had an internal lysine. Peptide (25 residues long) from A
> also had histidine, methionine, tyrosine, serine and threonine; peptide (70
> residues long) from B had cysteine, tryptophan, histidine, methionine,
> tyrosine, serine and threonine. Of course, both had amino acids like
> glycine, alanine and amides. The question is what other reactions might
> occur in the presence of carbodiimide that cross-links these two peptides.
> It will take more than the 5 pMol of this product that we have to find the
> site of cross-linking. Thanks for considering this problem.
>
>