Non-heme iron enzymes: Contrasts to heme catalysis

Non-heme iron enzymes: contrasts to heme catalysis.

Non-heme iron enzymes catalyze a wide range of O(2) reactions, paralleling those of heme systems. Non-heme iron active sites are, however, much more difficult to study because they do not exhibit the intense spectral features characteristic of the porphyrin ligand. A spectroscopic methodology was developed that provides significant mechanistic insight into the reactivity of non-heme ferrous act...

Divergent non-heme iron enzymes in the nogalamycin biosynthetic pathway.

Nogalamycin, an aromatic polyketide displaying high cytotoxicity, has a unique structure, with one of the carbohydrate units covalently attached to the aglycone via an additional carbon-carbon bond. The underlying chemistry, which implies a particularly challenging reaction requiring activation of an aliphatic carbon atom, has remained enigmatic. Here, we show that the unusual C5''-C2 carbocycl...

Dioxygen Activation by Enzymes Containing Binuclear Non-Heme Iron Clusters.

Modeling non-heme iron proteins.

Synthetic modeling studies of non-heme iron proteins continue to contribute to our understanding of the mechanism of these proteins. Recently, mononuclear Fe(IV)=O complexes have been prepared and characterized to model the same species that are proposed to be the reactive intermediates in reactions involving mononuclear non-heme iron proteins. Generation of such species for the oxidation of or...

EPR of Mononuclear Non-Heme Iron Proteins.

Flexible geometry of three- to six-protein side-chain ligands to non-heme iron in proteins is the basis for widely diverse reactivites ranging from iron transport to redox chemistry. The gap between fixed states determined by x-ray analysis can be filled by spectroscopic study of trapped intermediates. EPR is a versatile and relatively quick approach to defining intermediate states in terms of ...