Peptide synthesis: difference between revisions
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| Revision 22 — 12:47, 17 May 2025 FreightFenna (talk) add the figure for the lyophilisation cycle and caption it 4,134 bytes ±0 | Revision 23 — 14:10, 6 Jun 2025 PrepHPLC_Pia (talk) add the light-exposure point for photosensitive material 4,967 bytes +833 | ||
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| 30 | Difficult sequences make the arithmetic worse. Aggregation of the growing chain on the support hides the reactive terminus and depresses coupling yields locally, which is why particular regions of a sequence rather than the whole are usually responsible for a poor crude. See [[Solid-phase peptide synthesis]].{{r|merrifield1963}} | 30 | Difficult sequences make the arithmetic worse. Aggregation of the growing chain on the support hides the reactive terminus and depresses coupling yields locally, which is why particular regions of a sequence rather than the whole are usually responsible for a poor crude. See [[Solid-phase peptide synthesis]].{{r|merrifield1963}} |
| 31 | 31 | ||
| + | 32 | == Downstream of the chain == | |
| + | 33 | Cleavage from the support releases the peptide and, in Fmoc chemistry, removes the side-chain protecting groups simultaneously in a single strongly acidic treatment. Scavengers are included to trap the reactive cations released, which would otherwise alkylate sensitive residues. See [[Resin cleavage]].{{r|behrendt2016}} | |
| + | 34 | ||
| + | 35 | The resulting crude is precipitated, then purified by [[Preparative HPLC purification|preparative chromatography]] and isolated by [[Lyophilisation|lyophilisation]]. Because the mobile phase is acidified with trifluoroacetic acid, the isolated solid is a [[Trifluoroacetate counterion|trifluoroacetate salt]] unless exchanged.{{r|usp1503}} | |
| + | 36 | ||
| 32 | == References == | 37 | == References == |
| 33 | {{reflist}} | 38 | {{reflist}} |
| 34 | <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> | 39 | <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> |
| 35 | <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). DOI:10.1002/psc.2836. PMID 26785684.</ref> | 40 | <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). DOI:10.1002/psc.2836. PMID 26785684.</ref> |
| + | 41 | <ref name="usp1503">United States Pharmacopeia, General Chapter <1503>, ''Quality Attributes of Synthetic Peptide Drug Substances''.</ref> | |
| 36 | 42 | ||
| 37 | == See also == | 43 | == See also == |