. 1998 Mar 17;95(6):2868–2873. doi: 10.1073/pnas.95.6.2868

Table 1.

Kinetic parameters of wild-type and mutant chorismate mutases

Protein	Value of protein with amino acid replacement
	Inhibited (100 μM tyrosine)			Unliganded			Activated (10 μM tryptophan)
	k_cat, s⁻¹	K_m, S_0.5, mM	n_H	k_cat, s⁻¹	K_m, S_0.5, mM	n_H	k_cat, s⁻¹	K_m, S_0.5, mM	n_H
Wild type	240	6.2^*	1.7	342	4.0	1.5	361	0.4	1.1^†
Thr-226 → Ile	362	0.7	0.6^†	361	0.9	0.6^†	351	0.4	0.7^†
Ile-225 → Thr-	366	3.5	1.3	320	3.6	1.3	535	1.5	0.7^†
Thr-226 → Ile
Glu-23 → Asp	655	9.5^*	1.2^†	630	4.5	1.1^†	625	1.6	1.0^†
Glu-23 → Gln	14	5.4^*	1.4	31	10.7^*	1.3	171	6.0	1.1^†
Glu-23 → Ala	^‡	^‡	^‡	^‡	^‡	^‡	14	5.2	1.2
Tyr-234 → Phe	457	1.2	1.4	420	0.9	1.2	565	0.7	1.0^†
Tyr-234 → Ala	243	1.2	1.1^†	228	1.1	1.2^†	252	0.8	1.3
Tyr-234 → Ser	66	2.6	1.3	72	3.2	1.3	74	1.3	1.7
Tyr-234 → Glu	44	7.0^*	1.1^†	47	7.3^*	1.0^†	44	6.3^*	1.1^†

Values for k_cat, K_m, and S_0.5 were determined by fitting initial velocity data to equations describing hyperbolic or cooperative saturation, respectively. Hill coefficient (n_H) values were calculated from Hill plots by linear regression.

Values had uncertainty intervals of more than 10% according to the fitting procedure.

^†

Hyperbolic saturation was indicated by linearity of the Eadie–Hofstee plots.

^‡

No measurable chorismate mutase function was detected.