> Dear ABRF friends,
>
> We want to synthesize a 26-mer peptide for one of our users. The
> sequence of the peptide is as folows:
>
> NH2-GSSSGQLQSYICFC*LPAFEGRNC*ETH-COOH
>
> The investigator wants cysteines #14 & 23 to form the disulfide bond,
> while cys 12 to remain free. Any suggestions for synthesis strategy will
> be appreciated.
Satya,
Use different protecting groups, e.g. protect 2 Cys with TFA labile
trityl groups and one Cys with TFA-stable groups, like Acm, MeBzl or
SBut. Then deprotect with TFA two cysteins, form disulfide bond,
and, finally, deprotect the remaining cystein.
Hope it helps,
ma
M. Alterman, Ph.D.
Director,
Biochemical Research Service Laboratory
University of Kansas
Lawrence, KS 66045
Phone: (913)-864-4166
(913)-864-4247 lab
FAX: (913)-864-5396
http://www.idl.ukans.edu/anylresc/brsl/brsl.html