Mechanistic Investigation of Methylphosphonate Synthase, a Non-Heme Iron-Dependent Oxygenase

Mechanistic Investigation of Methylphosphonate Synthase, a Non-Heme Iron-Dependent Oxygenase

Methylphosphonate synthase is a non-heme iron-dependent oxygenase that converts 2-hydroxyethylphosphonate (2-HEP) to methylphosphonate. On the basis of experiments with two enantiomers of a substrate analog, 2-hydroxypropylphosphonate, catalysis is proposed to commence with stereospecific abstraction of the pro-S hydrogen on C2 of the substrate. Experiments with isotopologues of 2-HEP indicate ...

A Novel Three-Component Rieske Non-Heme Iron Oxygenase

Conversion of a non-heme iron-dependent sulfoxide synthase into a thiol dioxygenase by a single point mutation.

EgtB from Mycobacterium thermoresistibile catalyzes O2-dependent sulfur-carbon bond formation between the side chains of Nα-trimethyl histidine and γ-glutamyl cysteine as a central step in ergothioneine biosynthesis. A single point mutation converts this enzyme into a γ-glutamyl cysteine dioxygenase with an efficiency that rivals naturally evolved thiol dioxygenases.

Regulation of endothelial heme oxygenase activity during hypoxia is dependent on chelatable iron.

The regulation of heme oxygenase (HO) activity and its dependence on iron was studied in bovine aortic endothelial cells (BAEC) subjected to hypoxia-reoxygenation (H/R). HO activity was induced by hypoxia (10 h) and continued to increase during the reoxygenation phase. HO-1 protein levels were strongly induced by hypoxia from undetectable levels and remained elevated at least 8 h postreoxygenat...

Neural roles for heme oxygenase: contrasts to nitric oxide synthase.

The heme oxygenase (HO) and nitric oxide (NO) synthase (NOS) systems display notable similarities as well as differences. HO and NOS are both oxidative enzymes using NADPH as an electron donor. The constitutive forms of the enzyme are differentially activated, with calcium entry stimulating NOS by binding to calmodulin, whereas calcium entry activates protein kinase C to phosphorylate and activ...