TABLE 1.

Kinetic and equilibrium binding parameters for SK·Pm and SKΔK414·Pm formation

Kinetic constants determined from analysis of the forward and reverse reactions and by numerical integration are listed for Equation 4 in the absence of kringle ligands (No effector), the presence of saturating 6-AHA, and saturating benzamidine. K_D,overall, calculated from the kinetic parameters and measured by fluorescence titration, and fluorescence change amplitudes (ΔF_max/F_o), determined from the kinetic analysis for the indicated species, are listed. Experiments were performed and analyzed as described under “Experimental Procedures.”

	K1 (encounter)	k2	k−2a	k3	k−3a	KD,overall	koff	ΔFmax/Fo
	nm	s−1	s−1	s−1	s−1	pm	s−1	%
No effector
SK	62 ± 2a	10.0 ± 0.1a	0.15 ± 0.01	1.2 ± 0.1a	0.009 ± 0.001	7 ± 1b	0.0008 ± 0.0001a	SK·Pm*, −48 ± 2
	110 ± 20c	9.6 ± 0.3c		0.9 ± 0.2c		12 ± 4d	0.0007 ± 0.0001b	SK·Pm**, −54 ± 2
SKΔK414	720 ± 6a	12.1 ± 0.1a	0.29 ± 0.01	0.8 ± 0.1a	0.003 ± 0.001	59 ± 3b	0.0007 ± 0.0001a	SK·Pm*, −42 ± 2
	670 ± 130c	12.7 ± 0.7c		1.4 ± 0.3c		190 ± 40d	0.0009 ± 0.0001c	SK·Pm**, −45 ± 2
6-AHA
SK	4900 ± 60a	34 ± 1a	1.07 ± 0.09	5.1 ± 0.2a	0.005 ± 0.001	140 ± 20b	0.0008 ± 0.0001a	SK·Pm*, −50 ± 2
	6500 ± 1400b	34 ± 1c		6.5 ± 0.4c		210 ± 20d	0.0007 ± 0.0001b	SK·Pm**, −59 ± 2
SKΔK414	5560 ± 50a	39 ± 1a	1.29 ± 0.01	5.0 ± 0.2a	0.004 ± 0.001	140 ± 20b	0.0008 ± 0.0001a	SK·Pm*, −45 ± 2
	7800 ± 1100c	43 ± 3c		6.4 ± 1.2c		350 ± 80d	0.0008 ± 0.0001c	SK·Pm**, −51 ± 2
Benzamidine
SK	1430 ± 30a	64 ± 2a	3.9 ± 0.8	17 ± 1a	0.015 ± 0.002	77 ± 20b	0.003 ± 0.001a	SK·Pm*, −26 ± 2
	2200 ± 500c	75 ± 5c		14 ± 4c		280 ± 160d	0.003 ± 0.001c	SK·Pm**, −31 ± 2
SKΔK414	2840 ± 20a	39 ± 1a	0.47 ± 0.01	4.0 ± 0.1a	0.020 ± 0.001	170 ± 50b	0.003 ± 0.001a	SK·Pm*, −28 ± 2
	4500 ± 1500c	46 ± 6c		7.8 ± 1.6c		370 ± 180d	0.003 ± 0.001c	SK·Pm**, −31 ± 2

^aDetermined by numerical integration.

^bCalculated from the kinetic parameters.

^cDetermined from the forward and reverse reactions.

^dMeasured by fluorescence titration (12, 13, and 37) and this paper for benzamidine.