our peptide,
ZSGALLSEQCCHIGCTRRSIAKLC
containing a C-term pyroGlu (Z) was synthesized using either continuous flow=
Fmoc or Boc strategy; interestingly in both cases a major side-product=
appeared with an apparent mass of +112. Stable under standard reduction=
conditions (dithiothreitol, Tris buffer pH 8, 1 hr at 37=B0C), its=
reconversion to the original peptide could be achieved by reducing the=
peptide under the same conditions at 50=B0C=20
I believe, this side-product is an trifluoroactate adduct appearing either=
during the cleavage (Fmoc strategy) or during the work-up procedure, where=
a 0.1% TFA aqueous buffer was used to dissolve the peptide (Boc strategy).
Maybe this could solve your problem.....
Marc.
-------------------------------------------------
Dr. Marc Mathieu
Howard Florey Institute
University of Melbourne
Parkville 3052
AUSTRALIA
Tel. +61 3 9344 7285
Fax. +61 3 9348 1707
e-mail: m.mathieu@hfi.unimelb.edu.au
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marc.html
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