Isolation and characterization of renin-like aspartic-proteases from Echis ocellatus venom.

Three aspartic proteases (SVAPs) have been isolated from venom of the saw-scaled viper, Echis ocellatus. In confirmation of prior transcriptomic predictions, all three forms match to sequences of either of the two SVAP transcripts (EOC00051 and EOC00123), have a molecular weight of 42 kDa and possess a single N-glycan. The SVAPs act in a renin-like manner, specifically cleaving human and porcine angiotensinogen into angiotensin-1 and possess no general protease activity. Their activity is completely inhibited by the aspartyl protease inhibitor Pepstatin A.