Table 3. Steady-State Kinetic Parameters for SR(ΔRS2) Phosphorylation in the Absence and Presence of SR(RS2).

enzyme	[SR(RS2)] (nM)	kcat (s–1)	KSR (nM)
SRPK1	0	0.33 ± 0.04	30 ± 9
SRPK1	200	1.4 ± 0.20	28 ± 11
SRPK1(ΔN)	0	0.07 ± 0.02	63 ± 16
SRPK1(ΔN)	200	0.06 ± 0.01	72 ± 19
SRPK1(ΔS)	0	0.15 ± 0.02	26 ± 12
SRPK1(ΔS)	200	0.12 ± 0.01	25 ± 8
SRPK1(ΔSINT)	0	0.40 ± 0.04	57 ± 20
SRPK1(ΔSINT)	200	1.5 ± 0.13	66 ± 13
SRPK1(ΔSα1)	0	0.40 ± 0.04	48 ± 10
SRPK1(ΔSα1)	200	0.36 ± 0.03	55 ± 12