Editing Heme (section)

===Other hemes===
:''The following carbon numbering system of porphyrins is an older numbering used by biochemists and not the 1–24 numbering system recommended by [[IUPAC]], which is shown in the table above.''
* '''Heme ''l''''' is the derivative of heme B which is covalently attached to the protein of [[lactoperoxidase]], [[eosinophil peroxidase]], and [[thyroid peroxidase]]. The addition of [[peroxide]] with the [[glutamyl]]-375 and [[aspartyl]]-225 of lactoperoxidase forms ester bonds between these amino acid residues and the heme 1- and 5-methyl groups, respectively.<ref name="pmid9774411"/> Similar ester bonds with these two methyl groups are thought to form in eosinophil and thyroid peroxidases. Heme ''l'' is one important characteristic of animal peroxidases; plant peroxidases incorporate heme B. Lactoperoxidase and eosinophil peroxidase are protective enzymes responsible for the destruction of invading bacteria and virus. Thyroid peroxidase is the enzyme catalyzing the biosynthesis of the important thyroid hormones. Because lactoperoxidase destroys invading organisms in the lungs and excrement, it is thought to be an important protective enzyme.<ref>{{cite journal|last=Purdy|first= M.A.|title=Effect of growth phase and cell envelope structure on susceptibility of Salmonella triumphant to the lactoperoxidase-thiocyanate-hydrogen peroxide system|journal=Infect. Immun.|year=1983|volume=39|issue=3|pages= 1187–95|doi= 10.1128/IAI.39.3.1187-1195.1983|pmid=6341231|pmc=348082}}</ref>
* '''Heme ''m''''' is the derivative of heme B covalently bound at the active site of [[myeloperoxidase]]. Heme ''m'' contains the two [[ester bond]]s at the heme 1- and 5-methyl groups also present in heme ''l'' of other mammalian peroxidases, such as lactoperoxidase and eosinophil peroxidase. In addition, a unique [[sulfonamides|sulfonamide]] ion linkage between the sulfur of a methionyl amino-acid residue and the heme 2-vinyl group is formed, giving this enzyme the unique capability of easily oxidizing [[chloride]] and [[bromide]] ions to hypochlorite and hypobromite. [[Myeloperoxidase]] is present in mammalian [[neutrophil]]s and is responsible for the destruction of invading bacteria and viral agents. It perhaps synthesizes [[hypobromite]] by "mistake". Both hypochlorite and hypobromite are very reactive species responsible for the production of halogenated nucleosides, which are mutagenic compounds.<ref>{{cite journal|last=Ohshima|first= H.|title=Chemical basis of inflammation-induced carcinogenesis|journal=Arch. Biochem. Biophys.|year=2003|volume=417|issue=1|pages= 3–11|pmid=12921773|doi=10.1016/s0003-9861(03)00283-2}}</ref><ref>{{cite journal|last=Henderson|first= J.P.|title=Phagocytes produce 5-chlorouracil and 5-bromouracil, two mutagenic products of myeloperoxidase, in human inflammatory tissue|journal=J. Biol. Chem.|year=2003|volume=278|issue=26|pages= 23522–8|pmid=12707270|doi=10.1074/jbc.m303928200|s2cid= 19631565|doi-access=free}}</ref>
* '''Heme D''' is another derivative of heme B, but in which the [[propionic acid]] side chain at the carbon of position 6, which is also hydroxylated, forms a γ-[[spirolactone]]. Ring III is also hydroxylated at position 5, in a conformation ''trans'' to the new lactone group.<ref name="pmid8621527"/> Heme D is the site for oxygen reduction to water of many types of bacteria at low oxygen tension.<ref>{{cite journal|last=Belevich|first= I.|title=Oxygenated complex of cytochrome bd from Escherichia coli: stability and photolability|journal=FEBS Letters|year=2005|volume=579|issue=21|pages= 4567–70|pmid=16087180|doi=10.1016/j.febslet.2005.07.011|bibcode= 2005FEBSL.579.4567B|s2cid= 36465802}}</ref>
* '''Heme S''' is related to heme B by having a [[Formaldehyde|formyl]] group at position 2 in place of the 2-vinyl group. Heme S is found in the hemoglobin of a few species of marine worms. The correct structures of heme B and heme S were first elucidated by German chemist [[Hans Fischer]].<ref>{{cite book|last1 = Fischer|first1=H.|last2 = Orth|first2=H.|title =Die Chemie des Pyrrols|location = Liepzig|publisher = [[Ischemia Verlagsgesellschaft]]|date =1934|title-link=Die Chemie des Pyrrols}}</ref>

The names of [[cytochrome]]s typically (but not always) reflect the kinds of hemes they contain: cytochrome a contains heme A, cytochrome c contains heme C, etc. This convention may have been first introduced with the publication of the structure of [[heme A]].