4.1.99.5 octadecanal + O2 + 2 NADPH + 2 H+ = heptadecane + formate + H2O + 2 NADP+ - - 4.1.99.5 octadecanal + O2 + 2 NADPH + 2 H+ = heptadecane + formate + H2O + 2 NADP+ aldehyde-deformylating oxygenase (ADO) catalyzes conversion of a fatty aldehyde to the corresponding alk(a/e)ne and formate, consuming four electrons and one molecule of O2 per turnover and incorporating one atom from O2 into the formate coproduct. A cyanobacterial [2Fe-2S] ferredoxin (PetF), reduced by ferredoxin-NADP+ reductase (FNR) using NADPH, is implicated. Rapid reduction of the diferric-peroxyhemiacetal intermediate in ADO by a cyanobacterial ferredoxin. The enzyme follows a free-radical mechanism via radical and Fe2 III/III?PHA intermediate, reaction overview -, 748027 4.1.99.5 octadecanal + O2 + 2 NADPH + 2 H+ = heptadecane + formate + H2O + 2 NADP+ enzyme structures representing the different states during catalytic reaction -, 749212 4.1.99.5 octadecanal + O2 + 2 NADPH + 2 H+ = heptadecane + formate + H2O + 2 NADP+ mechanism of the unusual iron-catalysed decarbonylation reaction -, 727312 4.1.99.5 octadecanal + O2 + 2 NADPH + 2 H+ = heptadecane + formate + H2O + 2 NADP+ mechanistic proposal for the oxygen-independent formation of alkanes by the enzyme. In this mechanism the external reducing system functions catalytically to generate a reactive ketyl radical anion and facilitate carbon-carbon bond cleavage -, 726957 4.1.99.5 octadecanal + O2 + 2 NADPH + 2 H+ = heptadecane + formate + H2O + 2 NADP+ possible reaction mechanism, overview. Formate is the coproduct of alkane production by the Np AD, (ii) the aldehyde hydrogen of the substrate is retained in the formate, and (iii) the hydrogen added to C2 derives (at least in part) from solvent 715293 4.1.99.5 octadecanal + O2 + 2 NADPH + 2 H+ = heptadecane + formate + H2O + 2 NADP+ proposed mechanism for deformylation of aldehydes by cADO, overview. The rate of alkane formation is the same in D2O or H2O, implying that proton transfer is not a kinetically significant step. When the ratio of protium to deuterium in the product alkane is measured as a function of the mole fraction of D2O, a D2OSIEobs of 2.19 is observed. The SIE is invariant with the mole fraction of D2O, indicating the involvement of a single protic site in the reaction. An iron-bound water molecule is the proton donor to the alkane in the reaction -, 747074 4.1.99.5 octadecanal + O2 + 2 NADPH + 2 H+ = heptadecane + formate + H2O + 2 NADP+ proposed mechanism of cADO involving homolytic cleavage of the C1-C2 bond of aldehyde by di-iron peroxo species, and proposed mechanism for deformylation involving heterolytic cleavage of the C1-C2 bond 726552 4.1.99.5 octadecanal + O2 + 2 NADPH + 2 H+ = heptadecane + formate + H2O + 2 NADP+ reaction mechanism, overview -, 748032 4.1.99.5 octadecanal + O2 + 2 NADPH + 2 H+ = heptadecane + formate + H2O + 2 NADP+ the aldehyde proton is retained in formate and one of the oxygen atoms derives from molecular oxygen, whereas the proton in the product alkane derives from the solvent. Initial formation of a diferric intermediate in the cADO catalyzed reaction. Addition of a further electron to this complex is proposed to lead to its breakdown and scission of the C1-C2 bond. A radical mechanism for C1-C2 bond cleavage is supported by the observed ring-opening of cyclopropyl aldehydes and oxiranyl aldehydes designed to act as radical clocks during deformylation by cADO. Structure-function analysis -, 746597