Fig. 3.

ECE-1 degradation of SP. (A) Time course of degradation of SP by rhECE-1. ECE-1 degraded SP at pH 5.5 but not pH 7.4, and SM-19712 prevented degradation. (B–D) Degradation of internalized [³H]SP. (B) In KNRK-NK₁R cells, overexpression of ECE-1a–d accelerated degradation of [³H]SP (∗, P < 0.05) to KNRK-NK₁R cells. (C) In KNRK-NK1R cells, HPLC shows that [³H]SP[1–6] was the main degradation product. (D) In HEK-NK₁R cells, SM-19712 and bafilomycin A₁ abolished the rapid degradation of [³H]SP (∗∗, P < 0.01) to vehicle.