Open AccessO2 Activation by Non-Heme Iron Enzymes
Author(s) -
Edward I. Solomon,
Serra Goudarzi,
Kyle D. Sutherlin
Publication year - 2016
Publication title -
biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.43
H-Index - 253
eISSN - 1520-4995
pISSN - 0006-2960
DOI - 10.1021/acs.biochem.6b00635
Subject(s) - heme , chemistry , enzyme , substrate (aquarium) , electrophile , reactivity (psychology) , stereochemistry , photochemistry , combinatorial chemistry , catalysis , biochemistry , biology , ecology , medicine , alternative medicine , pathology
The non-heme Fe enzymes are ubiquitous in nature and perform a wide range of functions involving O 2 activation. These had been difficult to study relative to heme enzymes; however, spectroscopic methods that provide significant insight into the correlation of structure with function have now been developed. This Current Topics article summarizes both the molecular mechanism these enzymes use to control O 2 activation in the presence of cosubstrates and the oxygen intermediates these reactions generate. Three types of O 2 activation are observed. First, non-heme reactivity is shown to be different from heme chemistry where a low-spin Fe III -OOH non-heme intermediate directly reacts with substrate. Also, two subclasses of non-heme Fe enzymes generate high-spin Fe IV ═O intermediates that provide both σ and π frontier molecular orbitals that can control selectivity. Finally, for several subclasses of non-heme Fe enzymes, binding of the substrate to the Fe II site leads to the one-electron reductive activation of O 2 to an Fe III -superoxide capable of H atom abstraction and electrophilic attack.