At 02:30 PM 7/29/98 -0800, Richard S. Johnson wrote:
>
> Does anyone know where one can obtain synthetic O-GlcNAc peptides? If
> Gerald Hart is correct and O-GlcNAcylation is as common as
> phosphorylation it seems reasonable to wonder why no one seems to come
> across this modification all that frequently. In the days prior to
> when mass spectrometers were in every other protein chem lab, one can
> understand why this modification was overlooked. Now that mass
> spectrometers are as common as vortexers, why don't people stumble
> across O-GlcNAc more often. A possible explanation, according to
> Gerald Hart is that O-GlcNAc is largely unstable to electrospray and
> maldi (including IR MALDI). Does anyone have any experience w/
> O-GlcNAc peptides or know how to obtain synthetic peptides?
>
> Regards, Rich Johnson (rjohnson@immunex.com)
>
>
>______________________________ Reply Separator
_________________________________
>Subject: Re: Posttranslational Modifications
>Author: Ken Mitchelhill <k.mitchelhill@medicine.unimelb.edu.au> at Internet
>Date: 7/29/98 1:24 PM
>
>
>To: Ken Walsh
>
>Ken,
>
>In "the other Ken's" original post, he stated the doublet ran "about twice
>the distance between the phospho and non-phosho forms of either individual
>species" in isoelectric focussing.
>
>Gerald Hart presented his "dynamic glycosylation" data at Lorne this year
>and we have been looking out for it in some of the regulatory systems we
>are interested in. I am curious if you, or anyone else out there, knows how
>GlcNacylation would be expected to affect the isoelectric mobility of a
>protein?
>
>regards....Ken Mitchelhill
>
>>Ken
>>
>>An interesting possibility for a PTM would be attachment of a single
>>hexosamine (+161). Gerald Hart has found that specific glycation (with
>>GlcNac I think) acts to limit phosphorylation.
>>
>>Ken
>>
>>Kenneth A. Walsh
>>E.W.Davie/ZymoGenetics Chair of Biochemistry
>>Box # 357350
>>University of Washington
>>Seattle WA 98195
>>
>>walsh@u.washington.edu
>>Phone 206-543-1768
>>FAX 206-685-9231
>>
>>On Mon, 27 Jul 1998, Kenneth Williams wrote:
>>
>>> One of our users is working with a kinase that is phosphorylated at a
>>> single site. In addition, however, the non-phosphorylated (and
>>> dephosphorylated) kinase migrates as a doublet on isoelectric focussing -
>>> with the distance between the two (non-phosphorylated) species being
about
>>> twice the distance between the phospho and non-phosho forms of either
>>> individual species. My question is what are the most likely
>>> post-translational modifications that might give rise to the original
>>> doublet (assuming one species in not modified and that neiterh is
>>> phosphorylated).
>>>
>>> Thanks!
>>>
>>>
>>>
>>> Ken Williams, Ph.D.
>>> Director, HHMI Biopolymer/Keck Laboratory
>>> Professor (Adjunct) Research
>>> Molecular Biophysics and Biochemistry
>>>
>>>
>>> Visit the HHMI Biopolymer/Keck Laboratory Web Page at:
>>>
>>> http://info.med.yale.edu/wmkeck/
>>>
>>>
>
>
>********************************
>
>Ken I. Mitchelhill
>The John Holt Protein Structure Laboratory
>St. Vincent's Institute of Medical Research
>41 Victoria Parade
>Fitzroy 3065 Victoria
>AUSTRALIA
>
>Telephone: 61-3-9288 2480
>Facsimile: 61-3-9416 2676
>
>Email: k.mitchelhill@medicine.unimelb.edu.au
>
>Laboratory: http://www.medstv.unimelb.edu.au/WWWDOCS/SVIMRdocs/JHPSL.html
>ABRF: http://www.abrf.org
>
>***********************************
>
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