Chemical structure of angiotensin in the turtle, Pseudemys scripta

The chemical structure of angiotensin generated by incubating kidney extract with homologous plasma from the turtle, Pseudemys scripta, has been analyzed. The turtle angiotensin was proposed to be [Asp1, Val5, His9] ANG I by its amino acid composition and by its fluorescent peptide mapping. It was the same structure as angiotensin I in the ox and the sheep. The N-terminal amino acid of the turtle angiotensin was not blocked, unlike that of another reptilian angiotensin found in the snake, Elaphe climacophora.