Fig. 3.

Activation of HTRA1 by substoichiometric inhibition. Proteolysis of tau (10 µM) by HTRA1 (1 µM) in the absence or presence of the fixed concentrations of the allosteric peptide SYAAWIDVEDL (10 and 150 µM) and various concentrations of the inhibitor DPMFKLV-B(OH)₂ (Inh) after 5 h incubation at 37 °C (Left). Quantification of the tau signal intensity using densitometry (n = 3) relative to the DMSO control; error bars indicate SD (Right). An additional 2 h time point of tau digests is shown in SI Appendix, Fig. S5C.