Peptide synthesis: difference between revisions
Diff·revision 12 → 13·09:36, 18 Nov 2024
Difference between revision 12 and revision 13 of Peptide synthesis. 5 lines changed; the page grew by 583 bytes.
| Revision 12 — 15:11, 30 Oct 2024 CDMO_Caradoc (talk) expand §Why yield falls with length 3,038 bytes +28 | Revision 13 — 09:36, 18 Nov 2024 ColdChainCleo (talk) rm the vendor-specific packaging detail; not general enough for the article 3,621 bytes +583 | ||
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| 23 | Coupling is driven by an activating reagent that converts the carboxyl group into a reactive species. Reagent choice affects both speed and the degree of racemisation at the activated centre, and is one of the main levers in optimising a difficult sequence. See [[Peptide coupling reagent]].{{r|behrendt2016}} | 23 | Coupling is driven by an activating reagent that converts the carboxyl group into a reactive species. Reagent choice affects both speed and the degree of racemisation at the activated centre, and is one of the main levers in optimising a difficult sequence. See [[Peptide coupling reagent]].{{r|behrendt2016}} |
| 24 | 24 | ||
| + | 25 | == Why yield falls with length == | |
| + | 26 | Because a peptide of ''n'' residues requires ''n'' couplings, overall yield is the product of the individual coupling yields. At 99% per coupling a 30-residue peptide is obtained in about 74% yield; at 98% it is about 55%; at 95% it is about 21%.{{r|behrendt2016}} | |
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| + | 28 | The material lost is not simply absent — it is present as truncated and deletion sequences, which remain attached to the support and are cleaved along with the target. These are the impurities that dominate a [[Crude peptide|crude]] peptide and that a purity method must resolve. | |
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| 25 | == References == | 30 | == References == |
| 26 | {{reflist}} | 31 | {{reflist}} |