Howdy! I recently saw a protocol by Promega which uses N-terminally dyed
oligopeptides to detect proteases in solutions. It's a really neat idea;
if the oligopeptide is cleaved, you suddenly have a shorter dyed peptide
with a different isoelectric point. By running your reaction mixtures on
an agarose gel, you can see a change in migration that is associated with
proteolytic cleavage.
Really neat stuff, but I'm looking for signal peptidase activity in my
organism, and the dyed oligopeptides Promega uses probably won't be cut by
this peptidase. Thus, I'm wondering if anybody has any good recipes for
attaching dyes to the N-terminus of proteins (or to attach dyes to proteins
in general; a N-terminal linkage would be most useful for the experiment I
have in mind, though.)
Thanks!
Ed Beaty
(Ed_Beaty at qms1.life.uiuc.edu)
