Angiotensin II generation by mast cell α-and β-chymases

GH Caughey, WW Raymond, PJ Wolters - Biochimica et Biophysica Acta …, 2000 - Elsevier
Mast cells secrete α-and β-chymases. Primate α-chymases generate angiotensin (AT) II by
selectively hydrolyzing AT I's Phe8–His9 bond. This is distinct from the AT converting
enzyme (ACE) pathway. In humans, α-chymase is the major non-ACE AT II-generator. In
rats, β-chymases destroy AT II by cleaving at Tyr4–Ile5. Past studies predicted that AT II
production versus destruction discriminates α-from β-chymases and that Lys40 in the
substrate-binding pocket determines α-chymase Phe8 specificity. This study examines these …