TABLE 2.

Steady-state kinetic parameters measured for wild-type, G200D and A261T Drosophila myosin S1

Values are mean ± S.D. based on a minimum of four preparations.

Myosin S1	Basal Ca-ATPase	Basal Mg-ATPase	Vmax	Km	Vmax/Km
	s−1	s−1	s−1	μm	μm−1s−1
Wild-type IFI	5.33 ± 0.62	0.09 ± 0.01	2.54 ± 0.29	5.77 ± 0.83	0.45 ± 0.09
S1G200D(Mhc5)	5.36 ± 0.27	0.14 ± 0.01a	2.60 ± 0.18	3.79 ± 0.67b	0.70 ± 0.08b
S1A261T(D45)	1.97 ± 0.46a	0.04 ± 0.01a	0.23 ± 0.04a	2.15 ± 0.73a	0.11 ± 0.02a

^a p < 0.001 determined by Student's t test as compared with IFI.

^b p < 0.01 determined by Student's t test as compared with IFI.