Editing Hemoprotein (section)

==Roles==
Hemeproteins have diverse biological functions including [[oxygen transport]], which is completed via hemeproteins including [[hemoglobin]], [[hemocyanin]],<ref>{{Cite web |title=hemoproteins - Humpath.com - Human pathology |url=https://www.humpath.com/spip.php?article14129 |access-date=2023-04-27 |website=www.humpath.com |archive-date=2023-04-27 |archive-url=https://web.archive.org/web/20230427032941/https://www.humpath.com/spip.php?article14129 |url-status=dead }}</ref> [[myoglobin]], [[neuroglobin]], [[cytoglobin]], and [[leghemoglobin]].<ref>{{cite book | vauthors = Lippard J, Berg JM | title = Principles of Bioinorganic Chemistry | publisher = University Science Books | location = Mill Valley, CA | date = 1994 | isbn = 0-935702-73-3}}</ref>

Some hemeproteins—[[cytochrome P450]]s, [[cytochrome c oxidase]], [[ligninase]]s, [[catalase]], and [[peroxidase]]s—are enzymes. They often activate O<sub>2</sub> for oxidation or hydroxylation.

Hemeproteins also enable [[electron transfer]] as they form part of the [[electron transport chain]]. [[Cytochrome c oxidase|Cytochrome a]], [[cytochrome b]], and [[cytochrome c]] have such electron transfer functions. It is now known that cytochrome a and cytochrome a3 make up one protein and was deemed the name cytochrome aa3.<ref>{{Cite journal |last1=Mahinthichaichan |first1=Paween |last2=Gennis |first2=Robert B. |last3=Tajkhorshid |first3=Emad |date=2018-04-10 |title=Cytochrome aa 3 Oxygen Reductase Utilizes the Tunnel Observed in the Crystal Structures To Deliver O 2 for Catalysis |journal=Biochemistry |language=en |volume=57 |issue=14 |pages=2150–2161 |doi=10.1021/acs.biochem.7b01194 |pmid=29546752 |pmc=5936630 |issn=0006-2960}}</ref> The [[sensory system]] also relies on some hemeproteins including [[FixL]], an oxygen sensor, [[CooA]], a carbon monoxide sensor, and [[soluble guanylyl cyclase]].