TABLE 2.

Half-lives of wild-type XynAS9 and its mutants for thermal inactivation^a

Enzyme	t1/2 (min)
	65°C	70°C	75°C	80°C
XynAS9	16	9	8	4
V81P mutant	27	12	7	4
G82E mutant	45	12	9	6
V81P/G82E mutant	255	94	33	15
D185P/S186E mutant	35	15	8	5
V81P/G82E/D185P/S186E mutant	228	81	33	18

^aThe enzyme activity was assayed at pH 6.5 and 70°C for 10 min.