Peptide: difference between revisions
Diff·revision 8 → 9·19:05, 30 Aug 2024
Difference between revision 8 and revision 9 of Peptide. 11 lines changed; the page grew by 865 bytes.
| Revision 8 — 12:12, 16 Aug 2024 CDMO_Caradoc (talk) expand §Peptides in research supply 2,681 bytes ±0 | Revision 9 — 19:05, 30 Aug 2024 CRP_Cormac (talk) clarify that the cake appearance is an indicator, not a specification 3,546 bytes +865 | ||
|---|---|---|---|
| 19 | Side chains determine chemistry. Charged residues set the isoelectric point and therefore the pH of minimum solubility; hydrophobic residues drive [[Peptide aggregation|aggregation]]; asparagine, glutamine and methionine introduce the specific chemical liabilities discussed at [[Deamidation]] and [[Methionine oxidation]]. | 19 | Side chains determine chemistry. Charged residues set the isoelectric point and therefore the pH of minimum solubility; hydrophobic residues drive [[Peptide aggregation|aggregation]]; asparagine, glutamine and methionine introduce the specific chemical liabilities discussed at [[Deamidation]] and [[Methionine oxidation]]. |
| 20 | 20 | ||
| + | 21 | == Nomenclature and notation == | |
| + | 22 | | Notation | Meaning | | |
| + | 23 | |---|---| | |
| + | 24 | | Three-letter code | Ala, Gly, Lys — used for readability | | |
| + | 25 | | One-letter code | A, G, K — used for long sequences | | |
| + | 26 | | Lower-case letter | D-amino acid, in some conventions | | |
| + | 27 | | Aib | α-aminoisobutyric acid, a common non-proteinogenic residue | | |
| + | 28 | | Numbering | From the N-terminus of the mature peptide unless stated | | |
| + | 29 | ||
| + | 30 | Numbering is a frequent source of confusion in the incretin literature, because GLP-1 is numbered from the N-terminus of proglucagon-derived GLP-1(1–37) while its active form begins at residue 7. The same substitution is therefore described as being at position 2 or position 8 depending on convention, which is why [[Semaglutide|semaglutide]] is described both as having Aib at position 8 and as having a substitution at the second residue of the active peptide.{{r|iupac}} | |
| + | 31 | ||
| 21 | == References == | 32 | == References == |
| 22 | {{reflist}} | 33 | {{reflist}} |