Table 1.

Kinetic parameters for wild-type HtrA1 and variants.

HtrA1 variant	Kcat (min−1)	Km (µM)	Kcat/Km (M−1 s−1)
Wild-type (positive control)	14.60 + −0.53	0.48 + −0.03	5.07 × 105
S328A (negative control)	Inactivea	Inactivea	Inactivea
R302A	Inactivea	Inactivea	Inactivea
E306A and R310A	5.99 + −0.16	0.28 + −0.01	3.56 × 105
K346I	1.46 + −0.15	0.67 + −0.31	0.36 × 105
L345G	1.15 + −0.03	0.14 + −0.02	1.37 × 105

(Supp. Figure S1, reaction rate plots). ^aThe protein is essentially inactive.