TABLE 1.

The kinetic parameters of wild-type RsPtxD and its mutants^a.

	NAD				NADP				CSRb	RCEc
Enzyme	KM (μM)	kcat (min–1)	kcat/KM (μM–1 min–1)	KM (μM, Pt)	KM (μM)	kcat (min–1)	kcat/KM (μM–1 min–1)	KM (μM, Pt)
RsPtxD	7.7 ± 2.3	127 ± 16.8	16.6	37.0 ± 7.0	418 ± 38.7	16.0 ± 6.3	4.0 × 10–2	338 ± 41.0	2.3 × 10–3
RsPtxDAR	412 ± 21.5	115 ± 13.0	0.3	452 ± 16.1	56 ± 5.1	91.1 ± 3.9	1.6	263 ± 16.4	6.0	0.1
RsPtxDHAR	154 ± 14.7	155 ± 2.3	1.0	419 ± 89.9	24 ± 5.2	118 ± 6.8	4.9	208 ± 6.2	5.0	0.3
RsPtxDHARKA	130 ± 10.6	154 ± 7.5	1.2	388 ± 46.6	4.4 ± 0.9	129 ± 12.1	29.6	27 ± 9.0	25.0	1.8
RsPtxDHARRA	112 ± 1.3	148 ± 14.8	1.3	414 ± 45.8	2.9 ± 0.5	128 ± 16.6	44.1	38 ± 8.5	34.0	2.7

^aAll assays were performed three times at 37°C, pH 7.3, in 100 mM MOPS.^bCofactor Specificity Ratio = (k_cat/K_M)^NADP/(k_cat/K_M)^NAD.^cRelative Catalytic Efficiency = (k_cat/K_M)^NADP_mut/(k_cat/K_M)^NAD_wt.