Fig 5. Suppression of KLK5-Induced Intracellular Calcium Mobilization by Native SFTI and Its Analogues.

Change in relative fluorescence unit (ΔRFU) was monitored continuously for about 5 minutes after injection of a mixture of KLK5 (774 nM) with various concentrations of native SFTI or its analogues. KLK5 and the inhibitors were diluted in 1xPBS and the concentration values indicate their final concentration in the well. For each tested ligand, a positive control (KLK5 Only) and negative control (Inhibitor Only) were performed to ensure the inhibitor and the diluent does not cause a signal. Total suppression of KLK5-induced intracellular calcium mobilization was achieved at an inhibitor-to-enzyme ratio of 2:1 for native SFTI (A), 4:1 for I10H (B.) and 1:1 for Analogue 2 (C) and Analogue 6 (D).