Table 3. Relative Binding Affinities of Ligands to the Wild-Type C1b Domain of PKCδ and to Mutated Versions Incorporating One or More of the Residues of PKCζ/ι Responsible for Its Loss of Ligand Binding Activity.

		Kd or Ki relative to that for PDBu binding to the wtδC1ba
compd	Kd, nM,a wtδC1B	N7R	S10R	P11R	L20R	N7R/P11R	N7R/L20R	N7R/S10R/P11R	N7R/S10R/L20R
PDBu	(0.23)	5.13	1.39	5.17	34.7	147	2090	85.2	5900
1-E	(2.95)	1.12	0.79	3.53	4.75	12.5	81.0	21.3	224
2-E	(2.46)	1.01	0.85	0.94	7.87	NTb	NTb	NTb	NTb
3-E	(2.95)	0.67	0.40	0.50	3.20	NTb	NTb	NTb	NTb
4-E	(2102)	0.30	0.40	0.20	1.34	2.47	21.8	NTb	NTb
5-E	(560)	1.41	1.45	1.27	12.4	6.79	209	NTb	NTb
5-Z	(865)	0.55	0.57	1.09	3.25	3.25	60.0	NTb	NTb
6-E	(1206)	1.44	1.46	2.79	4.57	13.2	87.0	NTb	NTb
7-E	(1070)	0.82	0.62	0.93	5.74	3.49	78.0	NTb	NTb
8-E	(300)	0.94	1.56	0.33	5.33	NTb	NTb	NTb	NTb
9-E	(96)	1.25	0.98	1.25	7.70	NTb	NTb	NTb	NTb
10-E	(1)	0.90	1.50	1.70	17.3	NTb	NTb	NTb	NTb
11-E	(0.5)	1.20	1.20	2.00	17.6	NTb	NTb	NTb	NTb
12-E	(0.6)	1.17	1.00	2.00	17.5	NTb	NTb	NTb	NTb
13-E	(777)	1.04	1.44	2.61	1.04	30.7	9.83	60.5	10.1

^aData are derived from Table 2.

^bNT, not tested.