Cardiovascular · Angiotensin-derived heptapeptide; AT1 and AT2 receptor agonist
Angiotensin III
Also known as Ang III; Ang-(2–8); Des-Asp¹-angiotensin II
An active seven-residue angiotensin fragment used to dissect AT1/AT2 signalling and sequential aminopeptidase processing.
- Length
- 7 amino acids
- Half-life
- Not well characterised
- Mechanism
- Angiotensin III activates AT1 and AT2 receptors, with relative potency depending on the experimental system. Aminopeptidase A generates it from angiotensin II, while aminopeptidase N can remove its N-terminal arginine to form angiotensin IV.
- Studied in
- Receptor-expressing cells, adrenal preparations, renal tissue and rodent neuroendocrine models examine angiotensin III signalling and aminopeptidase-dependent peptide turnover.
About Angiotensin III
Angiotensin III has the sequence Arg–Val–Tyr–Ile–His–Pro–Phe and corresponds to residues 2–8 of angiotensin II. Removal of the N-terminal aspartate by aminopeptidase A creates this heptapeptide without changing the C-terminal phenylalanine. Its identification helped establish that angiotensin degradation is not simply an inactivation process: shorter fragments can retain substantial receptor activity. Angiotensin III is therefore studied as an endogenous signalling peptide as well as a metabolic intermediate.
Both AT1 and AT2 receptors recognise angiotensin III, although affinity and functional potency vary with receptor expression, species and assay conditions. AT1-associated experiments often measure calcium mobilisation or phosphoinositide signalling, whereas AT2 studies require endpoints suited to the model. Brain and renal preparations are particularly useful for examining local peptide processing. Further cleavage by aminopeptidase N generates angiotensin IV, making metabolic controls important when interpreting prolonged incubations or complex tissue responses.
Laboratory notes
- For research use only. Check batch identity and distinguish angiotensin III from angiotensin II and IV using a validated analytical method.
- Monitor aminopeptidase activity in cell and tissue assays; use appropriately controlled inhibitors when separating parent-peptide effects from metabolite effects.
- Assess AT1 and AT2 contributions with receptor-selective controls rather than inferring receptor selectivity from a single functional endpoint.
Storage and reconstitution basics: storage guide.
Questions about Angiotensin III
How does angiotensin III differ from angiotensin II?
It lacks the N-terminal aspartate of angiotensin II, leaving a seven-residue peptide beginning with arginine.
Is angiotensin III an AT2-selective ligand?
No. It can activate both AT1 and AT2 receptors. Relative receptor contributions depend on the preparation and require experimental controls.
Which metabolite should be monitored during longer incubations?
Angiotensin IV is an important candidate because aminopeptidase N can generate it by removing the N-terminal arginine from angiotensin III.
Is Angiotensin III for human use?
No. It is supplied strictly for in-vitro laboratory research and is not for human or animal consumption.
Related research peptides
All products are sold for laboratory research use only. Not for human consumption, not a medicine, not for diagnosing, treating or preventing any condition.