TABLE II.

Effect of Mutations on the Stability of Tyrosine Hydroxylase

Enzyme	Apparent Tme	ΔTmf	kinacta (min−1)
Wild-type	48.2 ± 0.3	0	0.0068 ± 0.0014
	(53.9 ± 1.0)b
T245P	44.3 ± 0.1	3.9 ± 0.3	0.020 ± 0.001
T283M	ndc	nd	0.330 ± 0.026
R306H	45.8 ± 0.1b	8.2 ± 1.1d	0.142 ± 0.007
T463M	40.6 ± 0.1	7.7 ± 0.3	0.090 ± 0.003

^aFirst order rate constant for loss of activity at 50°C.

^bBuffer contained 10% glycerol.

^cnd, not determined.

^dCompared to wild-type enzyme in the presence of 10% glycerol.

^eDetermined from a fit of the data to Equation (3).

^fDifference in apparent T_m from wild-type enzyme.