Our experience with methylated amino acids has not been good,with the
exception of methyl
glycine.We have found that much longer deprotection and coupling of the
next amino acid
will give pretty good results.One of our peptides had MeAsp,and we gave up
on it.If synthesis was carried out under usual conditions,it appeared that
the next amino acid was
skipped entirely,while the one which was two removed went on pretty well.I
do not recall
that there was a problem of absolute yield,i.e. low yield,just that the
peptides had
deletions.To make things more complicated the amino acid analysis yields
are low for methyl
amino acids.We did not make a complete study,so this are raw facts.We got
enough of the
peptides that we wanted,and it was a pleasure to stop there.Good luck!
Krystyna Piotrowska <kpiotrow@interchange.ubc.ca>@aecom.yu.edu> on
04/28/2000 03:29:44 PM
Sent by: Association of Biomolecular Resource Facilities
<abrf-request@aecom.yu.edu>
To: Recipients of ABRF List <abrf@aecom.yu.edu>
cc:
Subject: PepeSyn
Hello everyone,
We would like to synthesize a short peptide containing two N-metylated
residues. Ser-Val-MetAsp-Val-MetGlu-Y.
The first attempt with the use of 433A synthesizer, with 0.1mM FastMoc
MonPrevPeak chemistry ( three deprotection loops) gave us only a few mgs
of the product. The conductivity tracing looked OK.
Any advices on the different coupling reagents, manipulation of
deprotection/coupling cycles, better (lower substitution?) resin
would be greatly appreciated.
Thanks in advance.
Krystyna
Dr. Krystyna B.Piotrowska
Protein Service Laboratory, NAPS
Biotechnology Laboratory
Room 237, Wesbrook Building
6174 University Boulevard
University of British Columbia
Vancouver B.C., V6T 1Z3
Canada
Tel. (604) 822 9662, Fax (604) 822 0676
www.biotech.ubc.ca/naps/napshome. htm
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