Large Scale ab Initio Quantum Chemical Calculation of the Intermediates in the Soluble Methane Monooxygenase Catalytic Cycle

摘要: Ab initio DFT quantum chemical methods are applied to study intermediates in the catalytic cycle of soluble methane monooxygenase hydroxylase (MMOH), a dinuclear iron-containing enzyme that converts and dioxygen selectively methanol water. The models reproduce reliably X-ray crystallographic coordinates active site for oxidized diiron(III) reduced diiron(II) states high degree structural precision. results inspired reexamination structure MMOH revealed previously unassigned electron density now attributed key water molecule. calculations required construction model containing about 100 atoms, which preserved hydrogen bonding patterns necessary integrity. Smaller were unstable form enzyme, an observation with significant mechanistic implications. large was then used investigate Hperoxo...