Vernon,
to answer your question, I need more information!
Which method you used to detect the potential by-products? I have used TCEP
to reduct disulfide bridges and I„ve never seen any by-products or other
side-chain products, for example in MALDI-MS.
But in ESI-MS, I saw peaks with a mass of 251 Da, 500, 750, 1001 etc.
After a lot of tests we establish that the peaks are "by-products" of TCEP.
The commercially available reagent has not mostly the best purity and it's
only durable for a very short time. So try a fresh reagent!
Best wishes, Suse
Susanne Neitz
Biologist
BioVisioN GmbH & Co. KG
Research & Development
Feodor-Lynen-Str.5
D-30625 Hannover
fon: +49(0)511-538896-52
fax: +49(0)511-538896-66
> Homepage: http://www.biovision.de
>
> -----Urspržngliche Nachricht-----
> Von: VERNON SHOUP [SMTP:vernon.shoup@regpha.com]
> Gesendet am: Mittwoch, 15. November 2000 14:25
> An: Recipients of ABRF List
> Betreff: TCEP reductions, side products
> Wichtigkeit: Niedrig
>
> In one of our processing steps for a protein drug, we will be using TCEP
> to reduce a disulfide bond. We do have to be aware of any potential side
> reactions. Is anyone aware of any side reactions when proteins are treated
> with TCEP?
>
> To prompt discussion, here are a couple of possibilities:
>
> 1. Incomplete reduction would produce a mixture of sulfhydryl groups and
> disulfide bonds, and might promote disulfide scrambling.
>
> 2. Suppose there were some methionine sulfoxide residues in the protein,
> due to previous oxidation. Would the reagent reduce those back to
> methionine?
>
> Vernon
>
> Vernon A. Shoup
> Regeneron Pharmaceuticals
> Rensselaer, NY
>
> (518)488-6012
> vernon.shoup@regpha.com
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