Table 2.

Binding and thermodynamic parameters for UCHL1^WT, UCHL1^GLU7ALA, UCHL1^CYS90SER, and UCHL1^ILE93MET

Parameters	UCHL1WT	UCHL1GLU7ALA	UCHL1CYS90SER	UCHL1ILE93MET
kcat (s−1)	0.188 ± 0.006	0.017 ± 0.005	ND	0.084 ± 0.003
Kd (nM)*	85 ± 31	646 ± 288	32 ± 6	29 ± 5
kcat/Kd (nM−1⋅s−1)	2.2 × 10−3	2.6 × 10−5	ND	2.8 × 10−3

Values shown are the average of three different experiments ± SD. k_cat, catalytic constant; K_d, dissociation constant; ND, not detectable.

*K_d values for all proteins were determined by isothermal titration calorimetry.