Figure 3.

PALeO, a dynamic MS-based protease assay, shows that ECE-1 converts angiotensin I to multiple biologically active metabolites including angiotensin II. The waterfall-plot shows the subsequent generation of Ang[1–9], angiotensin II and Ang[1–7] at extracellular pH (7.4). Red letters in the insert specify sites of proteolytic ¹⁸O-incorporation. Blue arrows indicate novel cleavage sites detected by PALeO, while the black arrow denotes the previously known cut site.⁶⁸.