Table I.

Binding constants of NIP1 variants and comparison with activities of NIP1 types I and II

NIP1 Type	Binding		H+-ATPase Stimulation				Elicitor Activity
	Kd, Ki	Ratioa	EC50	Emaxb	IRAc	IREd	EC50	Emaxb	IRAc	IREd
	nm		μm	%			μm	PI Units
I	5.6e		2.35	61.2	1.82		0.22	1.06 × 105	8.94
II	734f	130	2.86	40.9		72.0	2.14	1.15 × 105		14.7
III	Approximately 730f,g		–				–
IV	Approximately 730f,g		–				–
III*	13.7f		–				–
IV*	6.8f		–				–

^aK_i type II/K_d type I.

^bMaximal response: stimulation of the H⁺-ATPase (% of unstimulated activity), PR5 mRNA accumulation (phosphoimager [PI] units).

^cIntrinsic relative activity.

^dIntrinsic relative efficacy:intrinsic efficacy (ɛ) of type II expressed relative to that of type I.

^eK_d.

^fK_i.

^gExpected.