Fmoc chemistry: difference between revisions
Diff·revision 5 → 6·05:38, 21 Aug 2024
Difference between revision 5 and revision 6 of Fmoc chemistry. 5 lines changed; the page grew by 670 bytes.
| Revision 5 — 02:28, 8 Aug 2024 StabilityStig (talk) add the reconstitution-stability sentence with its storage condition 1,950 bytes ±0 | Revision 6 — 05:38, 21 Aug 2024 ShortageShona (talk) expand §The cycle 2,620 bytes +670 | ||
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| 11 | Its predecessor, Boc chemistry, used acid for both and therefore required a much stronger acid for final cleavage — hydrogen fluoride — with the handling requirements that implies. Boc chemistry was the scheme of the original solid-phase method.{{r|merrifield1963}} Orthogonality is what made peptide synthesis a routine operation.{{r|behrendt2016}} | 11 | Its predecessor, Boc chemistry, used acid for both and therefore required a much stronger acid for final cleavage — hydrogen fluoride — with the handling requirements that implies. Boc chemistry was the scheme of the original solid-phase method.{{r|merrifield1963}} Orthogonality is what made peptide synthesis a routine operation.{{r|behrendt2016}} |
| 12 | 12 | ||
| + | 13 | Deprotection is monitored spectrophotometrically: the dibenzofulvene released when Fmoc is removed absorbs strongly, so the extent of each deprotection can be followed in real time. This is one of the few in-process checks available in stepwise synthesis.{{r|behrendt2016}} | |
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| 13 | == The cycle == | 15 | == The cycle == |
| 14 | Fmoc is removed with a solution of piperidine in dimethylformamide, which abstracts the fluorenyl proton and triggers elimination. The released dibenzofulvene is trapped by excess piperidine to prevent it alkylating the peptide.{{r|behrendt2016}} | 16 | Fmoc is removed with a solution of piperidine in dimethylformamide, which abstracts the fluorenyl proton and triggers elimination. The released dibenzofulvene is trapped by excess piperidine to prevent it alkylating the peptide.{{r|behrendt2016}} |
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| 16 | The resin is then washed and the next Fmoc-protected amino acid coupled using an activating reagent. See [[Peptide coupling reagent]]. The cycle repeats once per residue. | 18 | The resin is then washed and the next Fmoc-protected amino acid coupled using an activating reagent. See [[Peptide coupling reagent]]. The cycle repeats once per residue. |
| 17 | 19 | ||
| + | 20 | Side-chain protection uses acid-labile groups: tert-butyl for hydroxyl and carboxyl side chains, trityl for cysteine and asparagine, and sulfonyl-type groups for arginine. All are removed in the final acidic cleavage. See [[Resin cleavage]].{{r|usp1503}} | |
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| 18 | == References == | 22 | == References == |
| 19 | {{reflist}} | 23 | {{reflist}} |
| 20 | <ref name="behrendt2016">Behrendt R, White P, Offer J. "Advances in Fmoc solid-phase peptide synthesis." ''Journal of Peptide Science'' 22(1):4–27 (2016). PMID 26785684.</ref> | 24 | <ref name="behrendt2016">Behrendt R, White P, Offer J. "Advances in Fmoc solid-phase peptide synthesis." ''Journal of Peptide Science'' 22(1):4–27 (2016). PMID 26785684.</ref> |
| + | 25 | <ref name="usp1503">United States Pharmacopeia, General Chapter <1503>, ''Quality Attributes of Synthetic Peptide Drug Substances''.</ref> | |
| 21 | <ref name="merrifield1963">Merrifield RB. "Solid phase peptide synthesis. I. The synthesis of a tetrapeptide." ''Journal of the American Chemical Society'' 85(14):2149–2154 (1963). DOI:10.1021/ja00897a025.</ref> | 26 | <ref name="merrifield1963">Merrifield RB. "Solid phase peptide synthesis. I. The synthesis of a tetrapeptide." ''Journal of the American Chemical Society'' 85(14):2149–2154 (1963). DOI:10.1021/ja00897a025.</ref> |
| 22 | 27 |