. Author manuscript; available in PMC: 2009 Dec 31.

Published in final edited form as: J Am Chem Soc. 2008 Dec 31;130(52):17632–17633. doi: 10.1021/ja806354w

Table 1.

Kinetic parameters for SLO-1 and mutants in 0.1 M borate buffer (pH 9.0)^a

Enzyme form	k_cat^b (s^-1)	KIE^c	E_a(H) (kcal/mol)	ΔE_a^d (kcal/mol)	A_H (s^-1)	A_H/A_D	k_cat/K_M (μM^-1s^-1)
WT-SLO^e	297 (12)	81 (5)	2.1 (0.2)	0.9 (0.2)	9 × 10³ (2× 10³)	18 (5)	11 (1)
546A^e	4.8 (0.6)	93 (9)	4.1 (0.4)	1.9 (0.6)	4 × 10⁴ (3× 10⁴)	4 (4)	0.33 (0.1)
553A^f	280 (10)	93 (4)	1.9 (0.2)	4.0 (0.3)	7 × 10³ (2× 10³)	0.12 (0.06)	12 (1)
546A/553A^g	2.21 (0.09)	128 (3)	3.8 (0.4)	2.8 (0.4)	1.1 × 10³ (5 × 10²)	1.05 (0.45)	0.11 (0.02)

Data were collected from 15 to 50 °C.

The rate constants are reported for 30 °C.

KIE = ^Dk_cat = k_cat(H)/k_cat(D).

This is the isotope effect on E_a, ΔE_a = E_a(D) − ΔE_a(H).

This work.