TABLE 3.

Relationship between thermostability and the ratio of residues Trp and Tyr

Enzyme	Temperaturea	Total number of residues	Total number (Tyr/Trp)b	Terminal numberc	Surface numberd	Surface number/total number	Relative numbere
	ºC						%
SMMA	100	696	67	27	20	2.87	100
ThMA	60	588	45	18	4	0.68	23.7
NPase	50	588	48	15	9	1.53	53.3
TVAII	50	585	39	13	4	0.68	23.7
CDase	40–50	583	42	18	4	0.68	23.7

^a The temperature indicates the optimal temperatures for maximum enzyme activity.

^b The number of total Tyr and Trp residues.

^c The number of Tyr and Trp residues near the end of a secondary structure element.

^d The number of Tyr and Trp residues near the end of a secondary structure element and exposed at the surface.

^e The relative value of the surface number to the surface number of SMMA.