Most short peptides WILL precipitate. There are possibly some dipeptides
that will not. I have made numerous dipeptides and tripeptides and they
neraly always ALL precipitate but it can take several goes to
evaporate and re-triturate with diethyl ether. I believe the problem
is the presence of water in the scavenger mix which makes precipitation
difficult. Several treatments with ether will remove water as well.
But, to make life easier it is best to use the ether / water partition
method suggested by others.
Regards
Graham Bloomberg
Dept. Biochemistry
Medical School
University of Bristol
Bristol BS8 1TD
Bao- Shiang,
Many short peptides(5 residues or less) are hygrospcopic and cannot be
precipitated with ether. After TFA cleavage, evaporate the TFA and add water
to the residue, proceed to lyophilization.
Anita Hong
AnaSpec, Inc.
2149 O'Toole Avenue, Suite F
San Jose, CA 95131
(408)452-5055 (phone)
(408)452-5059 (fax)
e-mail: service@anaspec.com
home-page: www.anaspec.com
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AnaSpec was recognized as a "Leader of the Pack"
in custom peptide synthesis by The Scientist (October 27, 1997)
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-----Original Message-----
From: Bao-Shiang Lee <boblee@uic.edu>
To: Recipients of ABRF List <abrf@aecom.yu.edu>
Date: Tuesday, February 09, 1999 5:11 AM
Subject: Short peptide
>Hi everyone,
>
>I am trying to synthesize two short peptides (1. c(amc)vgc(amc) and 2.
>avga). After cleavage, they can not be precipitated by ether. Mass spectra
>show they are there. Any suggestions would be appriciated.
>
>Best regards,
>
>
>Bob Lee
>
>