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Determination of the Carbon Kinetic Isotope Effects on Propane Hydroxylation Mediated by the Methane Monooxygenases from Methylococcus capsulatus (Bath) by Using Stable Carbon Isotopic Analysis
Author(s) -
Huang DedShih,
Wu SuhHuey,
Wang YaneShih,
Yu Steve S.F.,
Chan Sunney I.
Publication year - 2002
Publication title -
chembiochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.05
H-Index - 126
eISSN - 1439-7633
pISSN - 1439-4227
DOI - 10.1002/1439-7633(20020802)3:8<760::aid-cbic760>3.0.co;2-k
Subject(s) - chemistry , methane monooxygenase , kinetic isotope effect , hydroxylation , carbon fibers , propane , isotopes of carbon , monooxygenase , photochemistry , organic chemistry , stereochemistry , methane , deuterium , physics , materials science , quantum mechanics , composite number , total organic carbon , composite material , enzyme , cytochrome p450
Authentic propane with known position‐specific carbon isotope composition at each carbon atom was subjected to hydroxylation by the particulate and soluble methane monooxygenase (pMMO and sMMO) from Methylococcus capsulatus (Bath), and the corresponding position‐specific carbon isotope content was redetermined for the product 2‐propanol. Neither the reaction mediated by pMMO nor that with sMMO showed an intermolecular 12 C/ 13 C kinetic isotope effect effect on the propane hydroxylation at the secondary carbon; this indicates that there is little structural change at the carbon center attacked during formation of the transition state in the rate‐determining step. This finding is in line with the concerted mechanism proposed for pMMO (Bath), and suggested for sMMO (Bath), namely, direct side‐on insertion of an active “O” species across the CH bond, as has been previously reported for singlet carbene insertion.