The original request for nonstandard AA elution positions included the
statement: "We need as much information as you have, including chromatograms,
references, and proof of structure or identity."
The part about proof-of-structure seems to imply that we need an LCQ
connected to our sequencers to contribute data. To identify nonstandard AAs,
most of us either (1) just buy the nonstandard AA and sequence a huge load of
it to identify the chromatogram position(s) of the PTH derivatives, (2)
sequence a peptide/protein known to contain the nonstandard AA or (3)
derivatize or modify a peptide/protein to produce the desired nonstandard AA
and then sequence it. In each case, the starting materials used in the
analyses are characterized, but the compounds in the eluting peaks are not.
Could you comment on what type of proof-of-structure contributors need to
provide?
Steve
====================
Stephen Tindall
Argo BioAnalytica, Inc.
Phone: 1-973-605-2100
Fax: 1-973-605-2104
StvTindall@aol.com
====================
Subj: Re: Protein seq non-std peaks
Date: 2/10/99 12:47:48 PM Eastern Standard Time
From: crank@pharmsun.wustl.edu (Mark W. Crankshaw)
Sender: abrf-request@aecom.yu.edu (Association of Biomolecular Resource
Facilities)
To: abrf@aecom.yu.edu (Recipients of ABRF List)
Hello! I would be happy to send you and any other interested party a copy of
the Mod PTH-AA's In Protein Seq handbook. Please email me your mailing
address.
The peak you are seeing is almost certainly methionine sulphone. Mass spec
would give certainty. The delta mass is +32 per occurence.
Also, please send any documentation of mod PTH-AA's elution positions to me or
Greg Grant (same mailing address). Especially relevant to a second edition
are instruments other than PEABI as well as the Procise. Regards, Mark.