RE: Pepsyn: 100-mer of Asp-Gly repeats

bcdchin@muccmail.missouri.edu
Tue, 25 Aug 98 17:12:00 CST

Michael,
You have a good plan. I was making a (CK)n polymer. The CK and then just
polymerizing didn't work. Had to use CKCK then polymerize. The CKCK was only
partially soluble. If he doesn't need a large amount, you might just want to
get a polymer and then gel purify the 100-mer fraction. Me thinks it will be
hard to get 100-mer average by just controlling the random polymerization
conditions.

M. Bodanszky has some excellent books on this: "The Practice of Peptide
Synthesis" , "Principles of Peptide Synthesis" and "Peptide Synthesis" There
are many other good books and references.

Your SPPS idea is also a logical approach. I've had lots of problems with
solubility of protected peptides. You'll have to play around with the solvents.
David Chin
Weather: Hot Hot and Hot. Was reasonable for a while, but it's back to a humid
90 plus. Grass is brown, but weeds continue to grow. I'm thinking of just
round-up treatment and just reseeding in the fall.

-----Original Message-----
From: msp@mcw.edu at MU-Internet
Sent: Tuesday, August 25, 1998 4:16 PM
To: abrf@aecom.yu.edu at MU-Internet
Cc: Chin, David T.
Subject: Pepsyn: 100-mer of Asp-Gly repeats

I have a customer who needs peptides of roughly 100 amino acids length
made up of asp-gly or glu-gly or asp/glu-gly-gly repeats. Poly-asp
and poly-glu are commercially available and he has done some
experiments with them, but poly-asp-gly (etc) seems not to be
commercially available. Unless someone knows of a source, that brings
us to the question of how to synthesize such things.

The two approaches that come to mind are:

1) Make Asp(OtBu)-Gly-OH (for example) and polymerize that in
solution. While my customer does not need a pure, single molecular
weight product, I fear that controlling the polymerization
sufficiently even to get molecular weights generally in the 10,000
region would be a research project in itself.

2) Make Fmoc-Asp(OtBu)-Gly-Asp(OtBu)-Gly-.....-OH (perhaps a 10-mer)
and then use 10 cycles of more-or-less conventional solid-phase
peptide synthesis to get a 100-mer. Solubility is the first potential
problem that comes to mind, but other show-stoppers probably exist,
too.

Has anyone done anything like this? Can anyone recommend any relevant
literature? Does anyone know of anyone who does work like this and
might be willing to take on this project for my customer?

--
Michael Pereckas  //  msp@mcw.edu  //  Michael.Pereckas@mixcom.com
Protein and Nucleic Acid Shared Facility, Medical College of Wisconsin
Research Technologist and sysadmin/webmaster of www.biochem.mcw.edu