From: benoiton@aix1.uottawa.ca
Date: Fri, 3 Jan 1997 15:23:10 -0500 (EST)
Subject: Re: peptide syn- '97
In-Reply-To: <n1360767364.8041@macmailgw.dfci.harvard.edu>
Message-Id: <Pine.A41.3.95.970103151233.47350A-100000@aix1.uottawa.ca>
To: Recipients of ABRF List <abrf@aecom.yu.edu>
Dear Tom:
I submit a short summary of the IUB-IUPAC convention for designating
substituted amino acids and peptides. This is the usual and recommended
way of designating synthetic work with peptides. What you are no doubt
used to is the sequencers' simplification which discards the terminal H
and OH that indicate the unbound terminal groups.
Amino-acid residues are represented by three-letter abbreviations or
symbols. A dash to the left of a symbol represents removal of H from
the alpha-amino group, a dash to the right represents removal of OH from the
alpha-carboxy group. Protecting groups are placed next to the dashes,
thus indicating their location. Unsubstituted amino or carboxy groups are
indicated by an H to the left and an OH to the right of the symbols. So
the peptide that elicited your question is the simple peptide amide; the
protonated form would correctly have to be indicated as H2+-Glu-- etc.
I hope this clarifies your uncertainties.
Leo Benoiton, benoiton@aix1.uottawa.ca
On 23 Dec 1996, Tom Brown wrote:
> Subject: Time:3:02 PM
> OFFICE MEMO peptide syn- '97 Date:12/23/96
>
> Hi, just a quick question about the peptide to be made for the ABRF study.
> The sequence given to us was:
>
> H-Glu-Asp-Tyr-Glu-Tyr-Thr-Ala-Arg-Phe-NH2
>
> I'm assuming the NH2 group implies a C-terminal amide group. However, I am not
> sure of the significance of the N-terminal H. Is this intended to signify a
> protonated amino group? I've never seen a peptide written in this way. Thanks
> in advance for your help.
>
> Tom Brown
> MBCF
> Dana Farber Cancer Institute
>
>