Fig. 5: dasTMPRSS2 peptidase activity is blocked by clinical protease inhibitors.
From: Structure and activity of human TMPRSS2 protease implicated in SARS-CoV-2 activation
a, Nafamostat and camostat are attacked by the catalytic Ser441 of TMPRSS2, with respective leaving groups 6-amidino-2-napthol and 4-Hydroxy benzeneacetic acid 2-(dimethylamino)-2-oxoethyl ester. b, A common phenylguanidino acyl–enzyme complex is formed after nafamostat or camostat treatment that specifically engages the S1 protease subsite. c, TMPRSS2 (blue) and TMPRSS15 (enteropeptidase, salmon; PDB ID 6ZOV) after nafamostat and camostat treatment, respectively. Catalytic triad residues are highlighted in bold and the conserved S1 subsite residue Asp435 shown. d, Clinical protease inhibitors preincubated for 5 min with dasTMPRSS2 block peptidase activity against Boc-QAR-AMC fluorogenic substrate with varying inhibitory potencies. Data are shown as mean ± s.d. and were performed in technical and biological duplicate (total n = 4) and curve fit for absolute IC50 in GraphPad. e, Reaction progress curves of residual dasTMPRSS2 peptidase activity after 10 s preincubation with the indicated concentrations of nafamostat and camostat inhibitors in the presence of 100 µM Boc-QAR-AMC substrate. Plateaus within progress curves demonstrate time-dependent acylation resulting in complete inhibition of dasTMPRSS2 peptidase activity. Data are shown as mean ± s.d. in technical duplicate (n = 2) and results were consistently obtained across n = 3 biological experiments.
