The catalytic mechanism of microsomal epoxide hydrolase involves reversible formation and rate-limiting hydrolysis of the alkyl-enzyme intermediate

Journal of the American Chemical Society

Volumn 118, Issue 39, 1996, Pages 9436-9437

  Tzeng, Huey Fen ^a   Laughlin, L Timothy ^a   Lin, Sue ^a   Armstrong, Richard N ^a  

^a University School of Medicine   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EPOXIDE HYDROLASE;

ARTICLE; ENANTIOMER; ENZYME ACTIVITY; FLUORESCENCE; HYDROLYSIS; MICROSOME; REACTION ANALYSIS;

EID: 0029911205     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja961826x     Document Type: Article

References (17)

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6. 3CN were mixed at 25°C in an Applied Photophysics SX-17MV stopped-flow spectrometer. Total fluorescence with excitation at 290 nm was observed through a 320 nm filter.
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8. The fact that saturation is observed with (2R)-1 indicates that the change in fluorescence is not associated wild formation of the Michaelis complex but rather a subsequent slower step It is assumed that the failure to observe saturation with (2S)-1 is due tc a much higher dissociation constant for this substrate.
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10. 2O at 1 mL/min) monitored at 260 nm.
11. 18O) resonances located 1.4 Hz upfield.
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17. With these substrates, ester formation can be detected directly by characteristic changes in UV absorption associated with opening of the oxirane ring. The observed rate constants for alkylation are at least 10-fold larger than the corresponding turnover numbers. Tzeng, H.-F.; Lin, S.; Lacourciere, G. M.; Armstrong, R. N. Unpublished results.