Fig. 2.
Assay of membrane APN activity of cultured cells.
(A) Determination of APN activity of cells incubated for 6 hours with peptidase inhibitors arphamenine B (Arpha.B), bestatin, or actinonin. (B) Determination of APN activity of cells incubated for 6 hours with CD13 mAb F23, WM15, or TÜK1. Data, from 1 experiment out of 4 (A) or 3 (B), are presented as percentages of the APN activity (405 nm absorbance) of peptidase inhibitor- or mAb-treated cells relative to control cells incubated without inhibitor or mAb.