I had replied to Mary directly,but I would like to comment on what you
said.I use the
AccQTag method,and I found 0.44 Thr in a peptide containing P-Thr,after
vapor phase
hydrolysis,1hr at 150.I paid little attention to the elution position of
P-Thr itself,Going
back to the old chromatograms,I saw a peak somewhere between Ser and
His,i.e. quite early
in the chromatogram.All this work went on over a few years,and I am pretty
convinced that
it is a pH/temp. effect.In the message to Mary,I reported that I use beta
elimination with
alkylation,using a mercaptan,thus making a cysteine derivatives.Still,it is
messy to work
with P-Thr.
Susana Linskens <linskens@qb.ffyb.uba.ar>@aecom.yu.edu> on 06/13/2000
12:09:47 PM
Sent by: Association of Biomolecular Resource Facilities
<abrf-request@aecom.yu.edu>
To: Recipients of ABRF List <abrf@aecom.yu.edu>
cc:
Subject: AAA
Dear mary:
I have just worked with standards and my experience is that
Phosphothreonine
is cleaved under acidic hydrolysis, leading to threonine, up to 60% of the
initial Phosphoderivative. P-Thr coelutes with aspartic acid in the PTC
procedure, in the 420 ABI Model, so you will see a higger aspartic than
expected ( due to the 40 % of the initial phosphoderivative ).
********************************************
Susana Linskens
LANAIS-PRO
Junin 956
1113 Buenos Aires - ARGENTINA
linskens@qb.ffyb.uba.ar
FAX: 54-11-4508-3652
Phone: 54-11-4508-3651
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