Incretin receptor agonist reference materials
Lyophilized reference material for in-vitro work on incretin receptor pharmacology. Supplied for laboratory research only.
- Compounds
- 2
- Purity, both lots
- 99.96%
- Certificates
- 2
- Method
- LCMS-UV
2 compounds in this line
What these molecules are
Retatrutide and tirzepatide are synthetic peptide agonists defined by the receptor sets they bind: tirzepatide at the GLP-1 and GIP receptors, retatrutide additionally at the glucagon receptor. Both carry a fatty-acid modification, the structural feature that governs solubility and behaviour in solution during sample preparation. Alphapep supplies them as characterised reference standards for receptor-binding and cell-based assay work, and offers them for no other purpose.
- Formula
- C221H342N46O68
- Mass
- 4,731.4 Da
- Supplied as
- 15mg
- Formula
- C225H348N48O68
- Mass
- 4,813.5 Da
- Supplied as
- 10mg
How each lot is characterised
Every lot is assayed by an independent laboratory using LCMS-UV. Two results are reported and they answer different questions: purity, as the percentage of total UV peak area attributable to the target compound, and identity, as a match between the measured mass of the principal peak and the calculated mass of the intended sequence. The certificate is issued against the specific lot rather than the compound, because peptide synthesis varies between batches.
Where the family sits
Both compounds in this line belong to a recognised structural family. InterPro and UniProt place them in the glucagon-secretin peptide superfamily, the group that also contains the native incretin sequences they are built on. Membership is a statement about fold and sequence relationship, and nothing more.
Where these two diverge
Structurally the two are close enough that the differences are worth stating exactly. Each is 39 residues, each ends in a C-terminal amide rather than a free acid, and each carries a single eicosanedioic acyl chain attached to a lysine through a gamma-glutamate spacer. They separate on four counts: the acyl chain sits at Lys20 in tirzepatide and Lys17 in retatrutide; the spacer carries two AEEA units in the first and one in the second; position 13 is alpha-aminoisobutyric acid in one and alpha-methyl-leucine in the other; and the segment spanning positions 23 to 28 differs outright.
- Compounds
- 2
- Assay method
- LCMS-UV
- Laboratory
- ACS Peptide Testing Labs
- Certificate date
- 2026-07-28
- Appearance
- White powder
Why that matters analytically
Those differences amount to C4H6N2, a separation of 82.11 Da in average mass. That gap is wide enough to be unambiguous by electrospray mass spectrometry, which is what makes telling the two apart a measurement rather than an inference.
Percentage of total UV peak area attributable to the target compound.
Measured mass of the principal peak against the calculated mass for the sequence.
Each certificate is issued against a specific accession, not against the compound.