Pyroglu formation in this peptide is, in this case, unlikely. The major
product may be caused by cyclization of the beta carboxyl group of the
aspartyl residue ( note the sequence ...-asp-gly-....) to form an internal
succinimide. Also possible, but less likely is dehydration of serine to
form dehydroalanine. Isolating and sequencing the main product may tell
you which amino acid is involved in the reaction.
Hope this helps,
Russ Lehrman
bower@biochem.purdue.edu
02/25/98 11:52 AM
To: abrf@aecom.yu.edu
cc: (bcc: Russ Lehrman/NeXstar)
Subject: Peptide Synthesis
Hello everyone,
I have synthesized a peptide with the sequence CDGSVWAQSESFPELK. The HPLC
shows two major peaks adjacent to each other with the major peak being a
dehydrated (-18) species of the peptide as shown by mass spec. I suspect
pyroglu. formation, but I'm not sure where. Can anyone comment on what
might have happened here and what I can do to prevent this if I need to
resynthesize??
Thanks in advance!
Mary
Mary Bower
Instrument Specialist
Purdue University
Department of Biochemistry
West Lafayette, IN 47907
Phone (765)494-6540
Fax (765)494-7897
email; Bower@Biochem.purdue.edu