Structural features of angiotensin II which are important for biologic activity.
In summary, the aromatic ring of phenylalanine (COOH-terminus) is the key to the intrinsic activity with Tyr4, also involved in activation of a response. The NH2-terminal residue is a determinant of duration of action. The side chains of Tyr4 and His6 are key determinants for affinity, and the amino acids in the No. 1 and No. 2 position also contribute to receptor binding. Val3, Ile5, and Pro7 contain neutral side chains which probably establish and/or help maintain the appropriate distances among the key sidechains of Tyr4, His6, and Phe8. In other words, Val3, Ile5 (or Val), and Pro7 are key determinants of structural conformation.
D000595:Amino Acid Sequence; D000803:Angiotensin I / Q000302:isolation & purification; D000804:Angiotensin II / Q000031:analogs & derivatives / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D006168:Guinea Pigs; D008968:Molecular Conformation; D011817:Rabbits; D051381:Rats; D013329:Structure-Activity Relationship
D000804:Angiotensin II; D000803:Angiotensin I