Using the HP version of Edman chemistry, "presequenced" Lys is detected
in the normal position after CNBr cleavage (60 degrees, 1 hr, 70% formic acid,
under argon). Lys does disappear after CNBr cleavage if OPA is used to block
the non-Pro sequences on samples that have not been
prederivatized/presequenced with PITC. That doesn't seem to fit your
situation.
Steve
====================
Stephen Tindall
Argo BioAnalytica, Inc.
Phone: 1-973-605-2100
Fax: 1-973-605-2104
StvTindall@aol.com
====================
Subj: ProtSeq: CNBr in situ
Date: 98-04-27 15:04:52 EDT
From: lcp2@mole.bio.cam.ac.uk (Len Packman)
Sender: abrf-request@aecom.yu.edu (Association of Biomolecular Resource
Facilities)
To: abrf@aecom.yu.edu (Recipients of ABRF List)
A number of proteins in a current sequencing project (PVDF blots) are
N-blocked and we are routinely treating the 'sequenced' sample on the
membrane with CNBr and then resequencing the sample to observe and
(hopefully) deconvolute the few signals which result. Many times this has
been successful, however I note that Lys does not show up at expected
positions; for non-blocked samples, Lys is detected.
So my question - in epsilon-PTC-lysine labile to CNBr treatment and
converted to something other than lysine? Do others observe this?
Len
*********************************************************************
Dr Len C. Packman
Assistant Director of Research
Protein and Nucleic Acid Chemistry Facility
Department of Biochemistry
University of Cambridge
80 Tennis Court Road
Old Addenbrookes Site
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Tel: +44 (1223) 333639 (including answerphone)
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