A carboxy-terminus truncated analog of angiotensin II, [Sar1]angiotensin II-(1-7)-amide, provides an entry to a new class of angiotensin II antagonists

One strategy to design peptidic hormone antagonists is based on the concept that a peptide hormone is composed of distinct binding and activating components. The authors used this strategy to design (Ser)angiotensin II-(1-7)-amide ((Sar)AII-(1-7)-NH sub(2)) as the most rational probe based on the hypothesis that residues 1-7 define the specificity, intensity, and duration of action of the biological effect, while the nature or residue 8 invokes agonist or antagonist activity. In addition Sar was introduced in position 1, a substitution known to increase the potency in other AII analogue series.