. Author manuscript; available in PMC: 2019 Dec 9.

Published in final edited form as: J Am Chem Soc. 2019 Sep 16;141(38):15153–15165. doi: 10.1021/jacs.9b06689

Table 2.

Differential ¹⁸O Incorporation at the Preferred and Alternative Positions in the LolO, H6H, and SyrB2 Reactions in H₂¹⁶O and ²H₂¹⁶O Solvent under ¹⁸O₂ Gas

Enzyme	Substrate	Preferred Site Solvent Exchange (%)		Alternative Site Solvent Exchange (%)		Number of Trials
		H₂O	²H₂O	H₂O	²H₂O
LolO	AcAP	~ 0^a	ND^b	9 ± 2	ND	8
LolO	2,2,8-d₃-AcAP	40.6 ± 0.2	28.8 ± 0.3	47.6 ± 0.4	32.8 ± 0.1	16
H6H	Hyo	12.5 ± 0.2	8.1 ± 0.3	66.0 ± 0.7	53.8 ± 1.7	3
H6H	6-d₁-Hyo	32.9 ± 0.4	24.6 ± 1.1	85.2 ± 0.3	73.7 ± 0.3	3
SyrB2	Nva	20	ND	50	ND	1
SyrB2	5,5,5-d₃-Nva	58 (58^c)	ND	69 (63^c)	ND	2

Incorporation of ¹⁸O in hydroxylation was not significantly different from incorporation into succinate, preventing its accurate determination

Value not determined.

Value when base hydrolysis was performed in 45% H₂¹⁸O