Heme-containing enzymes are enzymes that incorporate an iron–porphyrin cofactor within their catalytic machinery. Changes in iron oxidation state and coordination permit formation of reactive intermediates, including iron–oxygen species involved in substrate oxidation [1][2]. Heme-containing catalytic systems also participate in anaerobic nitrogen transformations, where c-type heme proteins mediate electron transfer and reactions involving nitrogenous substrates [3]. Binding of nitric oxide, oxygen-derived ligands, or other small molecules alters the electronic and geometric properties of the iron center [4]. The protein supplies axial ligands, substrate-binding regions, and a local environment that organizes these reactions. Heme association can also couple catalytic activity to regulatory changes in the protein [5].
- heme cofactor
- iron–porphyrin
- oxidoreductases
- oxygen activation
References
- Thomas L. Poulos; Heme Enzyme Structure and Function. Chem. Rev. 2014, 114, 3919-3962, 10.1021/cr400415k.
- Xiongyi Huang; John T. Groves; Oxygen Activation and Radical Transformations in Heme Proteins and Metalloporphyrins. Chem. Rev. 2017, 118, 2491-2553, 10.1021/acs.chemrev.7b00373.
- Boran Kartal; Jan T. Keltjens; Anammox Biochemistry: a Tale of Heme c Proteins. Trends Biochem. Sci. 2016, 41, 998-1011, 10.1016/j.tibs.2016.08.015.
- Nicolai Lehnert; Eunsuk Kim; Hai T. Dong; Jill B. Harland; Andrew P. Hunt; Elizabeth C. Manickas; Kady M. Oakley; John Pham; Garrett C. Reed; Victor Sosa Alfaro; et al. The Biologically Relevant Coordination Chemistry of Iron and Nitric Oxide: Electronic Structure and Reactivity. Chem. Rev. 2021, 121, 14682-14905, 10.1021/acs.chemrev.1c00253.
- Toru Shimizu; Alzbeta Lengalova; Václav Martínek; Markéta Martínková; Heme: Emergent Roles of Heme in Signal Transduction, Functional Regulation and as Catalytic Centres. Chem. Soc. Rev. 2019, 48, 5624-5657, 10.1039/c9cs00268e.