TABLE 3.

Binding and biological activity parameters of CCK1R mutants

Constructs	Binding Affinities		Binding Sites		Calcium Responses
	Ki		Sites/cell × 105		EC50
	nM				nM
	Untreated	+ MβCD	Untreated	+MβCD	Untreated	+MβCD
CCK1R, WT	4.3 ± 1.0	58.7 ± 10.5b	3.4 ± 0.5	2.1 ± 0.3	0.05 ± 0.01	0.24 ± 0.03b
CCK1R(Y140A)	0.6 ± 0.1a	0.8 ± 0.2	3.3 ± 0.6	2.3 ± 0.9	0.40 ± 0.08a	0.42 ± 0.11
CCK1R(W166A)	9.6 ± 2.4a	7.4 ± 1.5	2.6 ± 0.4c	3.0 ± 0.7c	0.29 ± 0.06a	0.50 ± 0.09b
CCK1R(Y237A)	37.5 ± 3.8a	65.9 ± 5.1b	3.8 ± 0.3	3.2 ± 0.2	0.05 ± 0.02	0.32 ± 0.07b

Data are expressed as means ± SEM of values from three to seven independent experiments.

^aP< 0.05 significantly different from wild-type CCK1R construct.

^bP< 0.05 significantly different from the same construct in the absence of MβCD treatment.

^cValues are expressed as number of sites/mg protein.