Table 3. Binding Data (pK_i Values) of Selected Pentapeptides (1, 2, 4–6, 16, 19, 23–25, and 35) at Casp1, Casp2, Casp3, Casp6, Casp7, and Casp9^a.

		pKi ± SD
sequence	Comp.	Casp1	N	Casp2b	N	Casp3b	N	Casp6	N	Casp7	N	Casp9	N
AcYKPVD-CHO	1	<4	2	4.56 ± 0.43	3	4.73 ± 0.10	4	<4	2	4.53 ± 0.19	2	<4.5	2
AcVDVAD-CHO	2	7.06 ± 0.06	2	7.85 ± 0.08	5	7.73 ± 0.09	5	<4	2	7.08 ± 0.06	2	5.57 ± 0.31	2
AcVDKVD-CHO	4	5.97 ± 0.12	2	7.40 ± 0.02	5	7.28 ± 0.09	4	<4	2	7.28 ± 0.10	2	4.77 ± 0.50	2
AcVDVKD-CHO	5	6.18 ± 0.20	2	7.63 ± 0.05	4	6.91 ± 0.07	4	<4	2	6.25 ± 0.07	2	<4.5	2
AcVDVVD-CHO	6	6.61 ± 0.13	2	7.77 ± 0.12	4	7.81 ± 0.13	4	4.93 ± 0.01	2	7.63 ± 0.07	2	5.52 ± 0.72	2
AcYDVKD-CHO	16	6.34 ± 0.01	2	7.83 ± 0.04	4	7.13 ± 0.02	4	<4	2	7.04 ± 0.01	2	4.72 ± 0.03	2
AcVD(Dab)VD-CHO	19	6.04 ± 0.02	2	7.44 ± 0.08	4	7.54 ± 0.02	4	<4	2	7.34 ± 0.11	2	5.17 ± 0.19	2
AcVDV(Orn)D-CHO	23	5.82 ± 0.04	2	7.45 ± 0.07	4	6.60 ± 0.08	4	<4	2	5.92 ± 0.01	2	<4.5	2
AcVDV(Dab)D-CHO	24	5.43 ± 0.16	2	7.26 ± 0.07	4	5.82 ± 0.18	4	<4	2	4.61 ± 0.36	2	<4	2
AcVDV(Dap)D-CHO	25	5.48 ± 0.08	2	6.77 ± 0.17	4	6.14 ± 0.09	4	<4	2	5.12 ± 0.09	2	<4	2
AcIDVKD-CHO	35	6.05 ± 0.03	2	7.68 ± 0.04	4	6.80 ± 0.10	4	<4	2	6.25 ± 0.11	2	<4.5	2

^aData shown are mean values ± SD of N independent experiments, each performed in duplicate or triplicate. Data were analyzed by nonlinear regression and were best fitted to sigmoidal concentration–response curves.

^bData at Casp2 and Casp3 are also shown in Table 2.