Date: Tue, 7 Jan 1997 10:12:59 -0600
From: lsteinke@molbio.unmc.edu (Laurey Steinke)
Message-Id: <199701071612.KAA27899@molbio.unmc.edu>
Subject: Prot seq: artifact peaks
To: Recipients of ABRF List <abrf@aecom.yu.edu>
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Dear David, Thank you for your reply. Yes I did mention an unknown artifact
between D and N. It is an old friend of mine. It's good to finally have a
name for it.
Ron, I too may be seeing peaks associated with lysine, also inconsistent in
appearance. Mine is also a doublet, the first larger than the second. The
first peak appears just before dehydro-alanine (S*) and the second is located
in the middle of Y and P. I am running Procise 491, premix with phosphate in
buffer A. I was looking for a beta-alanine in the peptide in which I saw these
anamolous peaks, and thought they _might_ be the location. Can anyone give
me a quick and dirty, ex cathedra answer on where to look for beta alanine?
Weather Inconsequential: another perfect winter day here. It's 30 degrees
and sunny. I only bemoan the lack of a snow cover: I want to do more
sledding.
-laurey
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>From dhawke@ix.netcom.com Sun Dec 22 00:27 CST 1996
From: dhawke@ix.netcom.com (David Hawke)
Subject: Prot seq: peak near Asp
To: lsteinke@unmc.edu (Laurey Steinke)
Dear Laura,
Some time back I think you mentioned a peak that you observed in LC
fractions that had been around for a while. Sorry for the delay in
writing, but I don't recall anyone addressing it. My guess is that
what you are seeing is probably the PITC adduct of ammonia or
phenylthiourea (PTU) which as I recall elutes very close to D most of
the time in that system (I worked with it for quite some time). In LC
fractions the acetonitrile can hydrolyze to give ammonia, then this
reacts with PITC during coupling. I think you can still buy PTU from
either Aldrich or Sigma.
Regards,
David Hawke
BioMolecular Technologies
email: dhawke@ix.netcom.com
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Laurey Steinke
Protein Structure Core Facility
Dept of Biochemistry and Molecular Biology
University of Nebraska Medical Center
Omaha, NE 68198-4525
telephone (402)559-6647
FAX (402)559-6650
lsteinke@molbio.unmc.edu