Exenatide: difference between revisions
Diff·revision 4 → 5·17:16, 1 Nov 2024
Difference between revision 4 and revision 5 of Exenatide. 5 lines changed; the page grew by 745 bytes.
| Revision 4 — 08:42, 20 Oct 2024 Retention_Time_Rae (talk) state plainly that the research-use-only form is not approved for human use 1,991 bytes +715 | Revision 5 — 17:16, 1 Nov 2024 KarlFischerKit (talk) rm the comparison to a compound with no published head-to-head data 2,736 bytes +745 | ||
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| 11 | Its therapeutic relevance rests on an accident of sequence: exendin-4 carries glycine rather than alanine at position 2, so [[Dipeptidyl peptidase-4|DPP-4]] does not cleave it. No engineering was required to obtain protease resistance — the peptide is naturally resistant, and this is why a venom peptide became a diabetes drug.{{r|nielsen2004}} | 11 | Its therapeutic relevance rests on an accident of sequence: exendin-4 carries glycine rather than alanine at position 2, so [[Dipeptidyl peptidase-4|DPP-4]] does not cleave it. No engineering was required to obtain protease resistance — the peptide is naturally resistant, and this is why a venom peptide became a diabetes drug.{{r|nielsen2004}} |
| 12 | 12 | ||
| + | 13 | Two formulations were marketed: a twice-daily immediate-release product, and a once-weekly extended-release product in which the peptide is encapsulated in poly(lactide-co-glycolide) microspheres. Both have been largely displaced by later agents with greater efficacy and simpler pharmacokinetics.{{r|drucker2018}} | |
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| 13 | == Origin and sequence == | 15 | == Origin and sequence == |
| 14 | Exendin-4 was identified in Gila monster venom in the early 1990s and shown to bind the mammalian GLP-1 receptor with high affinity despite substantial sequence divergence. The peptide is not a lizard GLP-1 orthologue; lizards have their own GLP-1, and exendin-4 is a separate gene product expressed in the salivary gland.{{r|nielsen2004}} | 16 | Exendin-4 was identified in Gila monster venom in the early 1990s and shown to bind the mammalian GLP-1 receptor with high affinity despite substantial sequence divergence. The peptide is not a lizard GLP-1 orthologue; lizards have their own GLP-1, and exendin-4 is a separate gene product expressed in the salivary gland.{{r|nielsen2004}} |
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| 16 | The C-terminal nine residues, absent from human GLP-1, form a tryptophan-cage motif that stabilises the helix and contributes to receptor affinity. This "Trp-cage" extension is the reason exendin-4 binds more tightly than native GLP-1 and is a frequently cited example of a natural product outperforming the endogenous ligand at its own receptor. | 18 | The C-terminal nine residues, absent from human GLP-1, form a tryptophan-cage motif that stabilises the helix and contributes to receptor affinity. This "Trp-cage" extension is the reason exendin-4 binds more tightly than native GLP-1 and is a frequently cited example of a natural product outperforming the endogenous ligand at its own receptor. |
| 17 | 19 | ||
| + | 20 | Glycine at position 2 provides the DPP-4 resistance. The resulting half-life of about 2.4 hours is still short — renal clearance dominates once proteolysis is removed — which is why the immediate-release product required twice-daily injection. | |
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| 18 | == References == | 22 | == References == |
| 19 | {{reflist}} | 23 | {{reflist}} |
| 20 | <ref name="nielsen2004">Nielsen LL, Young AA, Parkes DG. "Pharmacology of exenatide (synthetic exendin-4): a potential therapeutic for improved glycemic control of type 2 diabetes." ''Regulatory Peptides'' 117(2):77–88 (2004). PMID 14700743.</ref> | 24 | <ref name="nielsen2004">Nielsen LL, Young AA, Parkes DG. "Pharmacology of exenatide (synthetic exendin-4): a potential therapeutic for improved glycemic control of type 2 diabetes." ''Regulatory Peptides'' 117(2):77–88 (2004). PMID 14700743.</ref> |
| + | 25 | <ref name="drucker2018">Drucker DJ. "Mechanisms of action and therapeutic application of glucagon-like peptide-1." ''Cell Metabolism'' 27(4):740–756 (2018). PMID 29617641.</ref> | |
| 21 | 26 | ||
| 22 | {{DEFAULTSORT:Exenatide}} | 27 | {{DEFAULTSORT:Exenatide}} |