Table 4. Dissociation constants (K_d) and binding stoichiometry (N) of wild-type and mutant p97 N–D1 fragments for ATPγS and ADP determined by ITC^a.

N–D1 p97	ATPγS		ADP
	Kd (μM)b	N	Kd (μM)	N
Wild type	0.89±0.28	0.12±0.01	0.88±0.18	0.35±0.06
R53A	0.62±0.18	0.20±0.02	0.95±0.13	0.34±0.02
R86A	0.06±0.03	0.42±0.09	1.85±0.09	0.54±0.07
R95G	0.13±0.02	0.56±0.01	2.27±0.11	0.62±0.08
R155H	0.13±0.01	0.61±0.01	4.25±0.54	0.72±0.18
aAll numbers shown are averages of three independent experiments.
bITC with ATPγS for R86A, R95G, and R155H mutants showed biphasic titration curves and data were fitted with a two-site model. The Kd values for those mutants are derived from fitting to the first phase.