TABLE 2.

Kinetic analysis of Ffase mutants

The k_cat values were calculated assuming a protein molecular mass of 180 kDa. The ± sign refers to standard errors based on curve fitting using SigmaPlot.

Ffase mutant	kcat			Km			kcat/Km
	Sucrose	Nystose	Inulin	Sucrose	Nystose	Inulin	Sucrose	Nystose	Inulin
		s−1			mm			s−1mm−1
WT	105 ± 14	99 ± 6	19.9 ± 3	6.4 ± 0.9	2.1 ± 0.4	14.7 ± 2.4	16.4	47.1	1.3
Q176S	144 ± 28	208 ± 7	1220 ± 20	6.0 ± 0.8	30 ± 1.4	814 ± 8	24	6.9	1.5
Q176N	32 ± 3	50 ± 7	53.8 ± 6	6.7 ± 0.5	2.9 ± 0.2	102 ± 9	4.8	17.2	0.5
Q176E	82 ± 11	91 ± 2	18.5 ± 7	8.2 ± 1	2.5 ± 0.3	20.5 ± 2.7	10	36.4	0.9
Q228V	28 ± 5	1.8 ± 0.2	3.4 ± 0.2	10.7 ± 2	9.4 ± 0.9	52.5 ± 7.9	2.6	0.2	0.06
Q228T	29 ± 4	1.8 ± 1.9	5.0 ± 4.5	18.0 ± 8.4	11.3 ± 2	57.1 ± 6	1.6	0.2	0.087
Q228N	64 ± 11	30 ± 3.3	91 ± 8.1	16.1 ± 2.7	1.0 ± 0.2	23.9 ± 2.8	4	30	3.8
Q228E	38 ± 6	25 ± 3	409 ± 40	3.3 ± 0.5	1.2 ± 0.4	245 ± 32	11.5	20.8	1.7
N254A	80 ± 9	61 ± 3	11.3 ± 0.9	8.0 ± 0.9	9.2 ± 2	8.3 ± 0.8	10	6.6	1.3
N254T	10 ± 1	40 ± 8	2.1 ± 0.2	5.0 ± 5.5	9 ± 0.3	12.7 ± 1.1	2	4.4	0.2
N254D	31 ± 6	82 ± 3	4.4 ± 0.4	13.0 ± 2.4	4.8 ± 0.7	10.2 ± 1.2	2.4	17.1	0.4
N254E	16 ± 1	72 ± 2	1.3 ± 0.3	3.5 ± 0.4	19.5 ± 2	8.8 ± 1.3	4.6	3.7	0.1