(no subject)

Holyst, Trudy (tholyst@bcsew.edu)
Tue, 10 Aug 1999 10:13:09 -0500

Hello Roger, The same thing happened to me when I coupled FITC as
isothiocynate to peptide resin. I now use carboxyfluorescein, succinimidyl
ester from Molecular Probes, to label the amino ternimus of peptide resins
before deprotection of side chains. I generally add DMAP at 30% excess of
peptide resin conjugate (assuming 100% loading of peptide to resin) and rock
o/n at room temp on a nutator. I do the coupling in neat DMF and wash the
resin after with DCM so it can be dried and deprotected as usual.
Hope this helps,

Trudy Holyst

Peptide Core
Blood Research Institute
Blood Center of SE WI
Milwaukee, WI 53201

mtholyst@BCSEW.edu

-----Original Message-----
From: Roger Murphy [mailto:Roger.Murphy@ludwig.edu.au]
Sent: Monday, August 09, 1999 11:33 PM
To: Recipients of ABRF List
Subject:

Hi folks!

Any comments from anyone on the stability of an FITC-peptide conjugate at
low pH (say ~ 2)? I've labelled a decapeptide at the N-terminus with FITC
(i.e. as the isothiocyanate) but it looks as if it's fallen apart on
purification under standard RP-HPLC conditions (i.e. 0.1% TFA). We're
going to look at HPLC at pH 6.5 and at using succinimide ester derivatives
as well, but just wondered if anybody else has had a similar experience
with FITC and peptides.

Cheers,

Roger

------------------------------------------------------------
Roger Murphy, Ph.D.
Biological Production Facility
Ludwig Institute for Cancer Research
Austin & Repatriation Medical Centre
Studley Road,
Heidelberg, Vic. 3084
Australia.

Tel 61-3-94965463
Fax 61-3-94965436
Email Roger.Murphy@Ludwig.edu.au