I am a molecular biologist working with genes of proteins that disulfide
xlink to form networks. The basic structure is a central domain of
repetitive motifs flanked by termini containing all the cysteines.
We have constructed a bacterial expression construct to produce the
repetitive domain, and we're interested in possibly adding cysteines
to each end to see if we can obtain a xlinked matrix as with native
proteins. Adding one cysteine to each end is straighforward, but what if
we want to add several to increase the complexity of the xlinked network?
Could any protein chemists advise on what is known about the results
of placing multiple cysteines on the ends; ie., any way to predict the
availability of inter- vs intra-polypeptide disulfides? My limited
memory of protein chemistry is that adjacent cys cannot xlink (is that
true?), but what of additional ones? I would appreciate a discussion
with those of you more expert in this area. Thanks.
Olin Anderson
oandersn at pw.usda.gov
