Re: another CNBr-cleavage question
Jean Lucchetti (j.lucchetti@eurogentec.be)
Tue, 24 Feb 1998 12:49:12 -0800
pacl@mgrp.bgsm.edu wrote:
>
> We are synthesizing a peptide ARRTRRPMLRAVRIIAE . The Arg side
> chain group is [Pfb]. Has anyone had any experience using Fmoc chemistry
> for this side chain group, and what cleavage conditions were used?
>
> -----------------------------------------------------------------------------
> Mark Morris email: pacl@mgrp.bgsm.edu
> Biochemistry Department Phone: 336-716-2581
> Protein Analysis Core Laboratory Fax: 336-716-7200
> Bowman Gray School of Medicine
> Wake Forest University
> Medical Center Blvd.
> WInston-Salem, NC 27157
> -----------------------------------------------------------------------------
Mark,
The Pbf Arg side chain protecting group is a sulfonyl based protecting
group just like the Pmc or Mtr.
Basically, the chemistry used over the synthesis and the cleavage is the
classical one. Nevertheless, it's worth choosing the Pbf protecting
group mainly for the cleavage step: Pbf is remove faster than the Pmc,it
give rise to lower Trp sulfonation especially when used with alkyl
silane scavengers and last but not least it's cheaper. I routinelly used
Fmoc-Arg(Pbf) for my peptides synthesis with reagent K (in which
1,2-ethanedithiol has been replaced by the odorless triisopropylsilane)
as cleavage cocktail.
Hope this helps,
--
Jean LUCCHETTI, Ph.D.
EUROGENTEC Bel S.A.
Parc de Recherche Cense Rouge
B-4102 SERAING (BELGIUM)
Fax : (+ 32) 4 367 45 00
E-mail : <mailto:j.lucchetti@eurogentec.be>
Web site : <http://www.eurogentec.be> <----check it out !