pk of Threonin

[immunechem]

even at pH 14?
I though any OH group is analog of water. then should be ionizable

In article <Pine.GSO.4.05.9906031209120.14933-100000 at cbl.umces.edu>, 
reno at cbl.umces.edu says...
>
>
>Hi,
>
>Check out the URL address 
http://www.proteometrics.com/aainfo/contents.htm
>You'll find info on the pKa values for the side chains of amino acids 
that
>ionize.  Threonine's hydroxy side chain does not ionize. You won't find
>any pKa value for Thr, other than for its alpha amino and carboxyl 
groups.
>Only the side chains of the following amino acids will ionize: 
>
>Arg (guanido group)
>Asp (beta carboxylic acid)
>Cys (sulfhydryl) 
>Glu (gamma carboxylic acid)
>His (imidazole)
>Lys (epsilon amino group)
>Tyr (phenol) 
>
>
>Reno Nguyen
>
>
>On Thu, 3 Jun 1999, Steffen Schmidt wrote:
>
>> Date: Thu, 03 Jun 1999 07:49:30 +0200
>> From: Steffen Schmidt <sschmid2 at Uni-MolGen.gwdg.de>
>> Newsgroups: bionet.molbio.proteins
>> Subject: pk of Threonin
>> 
>> Hi,
>> 
>> does anyone know the pk-value of the hydroxy-group of threonin, or a
>> citation where I can find it.
>> 
>> Thanks, Steffen
>> 
>
>
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>Reno T. Nguyen
>Chesapeake Biological Laboratory                 /----\  /-----\   /
>Univ. MD Center for Environmental Science      /        /      /  /  
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>
>