Table 2. Summary of transient kinetic... | Rockefeller University Press

Table 2.

Summary of transient kinetic results for human M2β-S1 exchanged with K104E versus WT RLC

Rate/equilibrium constants (± SE)	WT	K104E
ATP binding (actomyosin)^a, n = 3
K’_1Tk’_+2T (µM^–1·s^–1)	7.7 ± 0.1	7.6 ± 0.3
K_0.5 (µM)	174 ± 60	62 ± 14
k’_+2T (s^–1)	1,527 ± 358	636 ± 76
Actomyosin ADP release (pyrene)^a, n = 4
k’₊_D (s^–1)	242.5 ± 17.2	284.4 ± 9.9
Actomyosin mantADP release^b, n = 4
k’₊_D (s^–1)	196.5 ± 15.6	157.1 ± 5.8

Rate/equilibrium constants (± SE)	WT	K104E
ATP binding (actomyosin)^a, n = 3
K’_1Tk’_+2T (µM^–1·s^–1)	7.7 ± 0.1	7.6 ± 0.3
K_0.5 (µM)	174 ± 60	62 ± 14
k’_+2T (s^–1)	1,527 ± 358	636 ± 76
Actomyosin ADP release (pyrene)^a, n = 4
k’₊_D (s^–1)	242.5 ± 17.2	284.4 ± 9.9
Actomyosin mantADP release^b, n = 4
k’₊_D (s^–1)	196.5 ± 15.6	157.1 ± 5.8

k’_+2T, maximal rate of ATP-induced dissociation; K’_1Tk’_+2T, second-order rate constant for ATP binding. K_0.5’, ATP concentration at which the observed rate constant is one-half maximal.

Pyrene actin fluorescence.

mantADP fluorescence.

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