Table 2.

Thermal Decay Rates: Results of the first (T1) and second (T2) half-life times (t_1/2) for the thermal stability of the purified ROS, WT, and I307 mutant Rhos, in the dark state. The decrease of the visible absorbance maximum with time was followed at 48 °C in the dark and the half-life times for the thermal decay were determined as described under the Materials and Methods section.

	ROS	ROS-VPA	WT	WT-VPA	I307N	I307N-VPA
T1 (min)	4.2 ± 0.3	6.3 ± 1.5	4.4 ± 0.6	6.8 ± 0.6	0.9 ± 0.2	0.7 ± 0.1
T2 (min)	35.5 ± 1.8	41.1 ± 2.4	38.1 ± 1.7	43.4 ± 1.8	25.7 ± 1.3	23.5 ± 0.1