Table 2.

Ratio of [γ -³²P]-8N₃ATP/[α -³²P]-8N3ATP labeling at NBD1 or NBD2

Samples
N-half	C-half	Ratioa at NBD1	Ratio at NBD2
Wild-type	Wild-type	2.12 ± 0.26b	0.70 ± 0.14
H827L	Wild-type	1.92 ± 0.45	0.90 ± 0.02
Wild-type	H1486L	1.89 ± 0.34	1.26 ± 0.12
H827L	H1486L	2.12 ± 0.32	1.38 ± 0.33
H827F	Wild-type	2.17 ± 0.15	0.93 ± 0.02
Wild-type	H1486F	2.15 ± 0.10	1.42 ± 0.14
H827F	H1486F	1.98 ± 0.20	1.42 ± 0.19

^aThe ratio (n = 4) of [γ -³²P]-8-N₃ATP/[α -³²P]- 8-N₃ATP labeling at NBD1 or NBD2 was derived from Figure 3. The amount of ³²P-8-N₃ATP incorporated into the N-half (NBD1) or C-half (NBD2) fragment was measured by employing Packard Instant Imager. The ratio of [γ -³²P]-8-N₃ATP/[α -³²P]-8-N₃ATP labeling at NBD1 or NBD2 was calculated by dividing the amount of [γ -³²P]- 8-N₃ATP labeling with that of [α -³²P]-8-N₃ATP labeling.

^bStatistical analysis indicated that the ratio values of NBD1 from all the mutants are not significantly different from that of wild-type NBD1 (2.12). The ratio values of NBD2 from H827L and H827F are also not significantly different from that of wild-type NBD2. In contrast, the ratio values of NBD2 from H1486L, H827L/H1486L, H1486F and H827F/H1486F are significantly different from that of wild-type NBD2 (0.70).