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Fmoc removal from cleaved peptide

Fmoc removal from cleaved peptide - Peptide Forum

Fmoc removal from cleaved peptide - Peptide Forum. Ask and discuss questions on peptide protocols, custom peptide synthesis, peptide identification and peptide sequencing.


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  #1  
Old 08-15-2008, 10:56 AM
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Default Fmoc removal from cleaved peptide



Dear all,

After cleaving and lyophilizing my peptide, i realized that i forgot to remove the Fmoc group off my last amino acid. This was confirmed through mass spec too. Now my peptide is in the powder form. Can i dissolve this powder in piperidine and get rid of the fmoc group and re lyophilize it?

what could be the potential problems if i do this?? Thank you for reading my post
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Old 08-15-2008, 11:25 AM
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Default Re: Fmoc removal from cleaved peptide

I have done this once or twice too. You can dissolve your peptide in minimum amount of 20% piperidine, keep it for about half an hour and re-precipitate your peptide. Your pure yield will probably go down but the F-moc will be removed.
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Old 08-15-2008, 12:28 PM
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Default Re: Fmoc removal from cleaved peptide

I would try to dissolve the peptide in 20%Piperidine/DCM put it on a stirrer for 1 hour, then evaporate the DCM, add Alcohol Ethylic and re-evaporate 3x. Precipitate the peptide with MTBE then whash it well (with MTBE).
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Old 11-03-2010, 09:21 PM
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Default Re: Fmoc removal from cleaved peptide

If you have a cysteine, then you are done for. Any amount of base will oxidize it during the Fmoc removal. To avoid adding some organics to my peptide to remove a Fmoc I have used aq ammonia. You will still be left with some cleave fmoc along with your product that will need to be removed by HPLC or some extraction method.
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Old 11-10-2010, 07:21 AM
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Default Re: Fmoc removal from cleaved peptide

Dissolve your peptide in 20% Piperidine/DCM for 30 min, then evaporate the DCM, then re-precipitate your peptide.
But if it goes for peptide with cysteine, ychack's advice is best.
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  #6  
Old 12-16-2010, 05:27 AM
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Thumbs up Re: Fmoc removal from cleaved peptide

I suppose you have to try morpholine or Diethylamine to remove Fmoc because these are volatile base so you remove it easily and also byproduct formed in this case can remove much more easily compare to byproduct formed with Piperidine.

Regards
Kunal Pandya
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Old 01-20-2011, 04:20 AM
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Default Re: Fmoc removal from cleaved peptide

Have a little more research on peptides so that you won't be confused on what to do..
I found out a site that can even help with the reconstitution of peptides.
See peptidecalculator.com
Good luck!
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