RE: Modification of tyrosine by the iodogen method
Breslav, Michael [PRI] (MBreslav@prius.jnj.com)
Sun, 21 Nov 1999 18:58:40 -0500
Brett,
Tyrosine will inevitably become diiodo-Tyrosine. There are actually
indications that it is easier to add the second iodine atom than the first.
Taking into account that the size of the iodine atom
is quite similar to the size of the aromatic ring, it is no surprise how
easy the biological activity may be alternated by extensive iodination (His
and Cys are sensitive too). What you can do (and what I've actually done) is
to synthesize your peptide using a commercially available
mono-iodo-tyrosine, purify it as much as you need and then perform a
radioactive iodine exchange. Let me know if you need references.
Regards,
Michael Breslav
R.W.Johnson PRI
Spring House, PA
> ----------
> From: Brett Phinney[SMTP:phinney@unity.ncsu.edu]
> Sent: Sunday, November 21, 1999 3:18 PM
> To: Recipients of ABRF List
> Subject: Modification of tyrosine by the iodogen method
>
> Hi, I was wondering if anyone knows of any rules concerning iodinating
> tyrosine by the iodogen method. Specifically, willÝa tyrosine always be
> iodinated multiple times if there is an excess of activated iodine over
> tyrosine residues?ÝConversely,Ýis it possible for a tyrosine to be
> modified only once in the presence of excess activated iodine?
> Ý
> Ý
> Thanks in advance for the info.
> Ý
> Ý
> --------------------------
> Brett Phinney
> Department of Biochemistry
> North Carolina State University
> ph# 919-515-5786 fax# 919-515-2047
> Ý
> Ý
> Ý
>