TABLE 1.

Summary of binding parameters Dissociation constants are listed for binding of [5F]Hir-(54–65)( ${\text{SO}}_3^{-}$) to ProT and Pre 1 species in buffers containing 110 mM NaCl (K_{H, Na}), 110 mM ChCl (K_{H, Ch}), their ratio (K_{H, Ch}/K_{H, Na}), and the corresponding maximum fluorescence changes ((ΔF_max/F_o⁾Na and (ΔF_max/F_o)Ch). Results were obtained by direct, kinetic, and end point titrations as described under “Experimental Procedures.”

Protein	Method	Dissociation constant		KH, Ch/KH, Na	Fluorescence change
		KH, Na	KH, Ch		(ΔFmax/Fo)Na	(ΔFmax/Fo)Ch
		nM			%
ProT	Direct titration	4000 ± 700	5400 ± 900	1.4	−18 ± 1	−19 ± 1
ProTR155A	Direct titration	1100 ± 300	1900 ± 300	1.7	−20 ± 3	−20 ± 2
Pre 1	Direct titration	510 ± 70	830 ± 140	1.6	−19 ± 1	−20 ± 1
Pre 2	Direct titration	640 ± 90	850 ± 120	1.3	−27 ± 1	−26 ± 1
Thrombin	Direct titration	48 ± 4	270 ± 20	5.6	−30 ± 1	−32 ± 1
FPR-thrombin	Direct titration	35 ± 6	51 ± 2	1.5	−31 ± 1	−30 ± 1
MzT(−F1)	Kinetic titration	41 ± 1	210 ± 5	5.1	−29 ± 1	−29 ± 1
MzT(−F1)	Endpoint titration	35 ± 6	200 ± 4	5.7	−28 ± 1	−29 ± 2
FPR-MzT(−F1)	Direct titration	26 ± 5	34 ± 3	1.3	−35 ± 1	−34 ± 1
FPR-MzT(−F1)	Kinetic titration	40 ± 2			−32 ± 1
FPR-MzT(−F1)	Endpoint titration	40 ± 20			−32 ± 3
MzTR155A	Kinetic titration	80 ± 3	830 ± 40	10.4	−33 ± 1	−35 ± 2
MzTR155A	Endpoint titration	100 ± 30	770 ± 120a	7.7	−34 ± 5	−35a
FPR-MzT	Direct titration	35 ± 4	41 ± 5	1.2	−34 ± 1	−34 ± 1

^aThe K_D for peptide binding to MzTR155A from the reaction end points in the absence of Na⁺ was obtained by fixing ΔF_max/F_o at −35%.