Editing Myoglobin

{{short description|Iron and oxygen-binding protein}}
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{{Infobox_gene}}

'''Myoglobin''' (symbol '''Mb''' or '''MB''') is an [[iron]]- and [[oxygen]]-binding [[protein]] found in the cardiac and [[skeletal muscle|skeletal]] [[Muscle|muscle tissue]] of vertebrates in general and in almost all mammals.<ref name="hardison">{{cite journal | vauthors = Ordway GA, Garry DJ | title = Myoglobin: an essential hemoprotein in striated muscle | journal = The Journal of Experimental Biology | volume = 207 | issue = Pt 20 | pages = 3441–6 | date = Sep 2004 | pmid = 15339940 | doi = 10.1242/jeb.01172 | doi-access = free }}</ref><ref name="Wick Hornick 2011 pp. 83–136">{{cite book | vauthors = Wick MR, Hornick JL | title=Diagnostic Immunohistochemistry | chapter=Immunohistology of Soft Tissue and Osseous Neoplasms | publisher=Elsevier | year=2011 | isbn=978-1-4160-5766-6 | doi=10.1016/b978-1-4160-5766-6.00008-x | pages=83–136 | quote=Myoglobin is a 17.8-kD protein that is found in cardiac and skeletal muscle and that forms complexes with iron molecules. }}</ref><ref name="Feher 2017 pp. 656–664">{{cite book | vauthors = Feher J | title=Quantitative Human Physiology | chapter=Oxygen and Carbon Dioxide Transport | publisher=Elsevier | year=2017 | isbn=978-0-12-800883-6 | doi=10.1016/b978-0-12-800883-6.00064-1 | pages=656–664 | quote= Highly oxidative muscle fibers contain a lot of myoglobin. It has two functions in muscle: it stores oxygen for use during heavy exercise, and it enhances diffusion through the [[cytosol]] by carrying the oxygen. By binding O2, myoglobin (Mb) provides a second diffusive pathway for O2 through the cell cytosol. }}</ref><ref name="Wilson Reeder 2006 pp. 73–76">{{cite book | vauthors = Wilson MT, Reeder BJ | title=Encyclopedia of Respiratory Medicine | chapter=MYOGLOBIN | publisher=Elsevier | year=2006 | isbn=978-0-12-370879-3 | doi=10.1016/b0-12-370879-6/00250-7 | pages=73–76 | quote=Myoglobin (Mb) is a heme-containing globular protein that is found in abundance in myocyte cells of heart and skeletal muscle. }}</ref><ref name="Boncyk 2007 pp. 193–199">{{cite book | vauthors = Boncyk JC | title=Complications in Anesthesia | chapter=Perioperative Hypoxia | publisher=Elsevier | year=2007 | isbn=978-1-4160-2215-2 | doi=10.1016/b978-1-4160-2215-2.50052-1 | pages=193–199 | quote=Myoglobin serves both as an O2 buffer and to store O2 in muscle. All known vertebrate myoglobins and β-hemoglobin subunits are similar in structure, but myoglobin binds O2 more avidly at low Po2 (Fig. 47-5) because it is a monomer (i.e., it does not undergo a significant conformational change with oxygenation). Thus, myoglobin remains fully saturated at O2 tensions between 15 and 30 mm Hg and unloads its O2 to the muscle mitochondria only at very low O2 tensions. }}</ref> Myoglobin is distantly related to [[hemoglobin]]. Compared to [[hemoglobin]], myoglobin has a higher affinity for oxygen and does not have [[cooperative binding]] with oxygen like hemoglobin does.<ref name="Wilson Reeder 2006 pp. 73–76"/><ref name="review">{{cite journal | vauthors = Hardison RC | title = Evolution of Hemoglobin and Its Genes | journal = Cold Spring Harb Perspect Med | volume = 2 | issue = 12 | pages = a011627 | date = Dec 2012 | pmid = 23209182 | doi = 10.1101/cshperspect.a011627 | pmc = 3543078 }}</ref>  Myoglobin consists of non-polar amino acids at the core of the globulin, where the heme group is non-covalently bounded with the surrounding polypeptide of myoglobin. In humans, myoglobin is found in the bloodstream only after [[Strain (injury)|muscle injury]].<ref name="Chung_2018">{{cite book | vauthors = Chung MJ, Brown DL | chapter = Diagnosis of acute myocardial infarction. | veditors = Brown DL | title = Cardiac Intensive Care-E-Book | date = July 2018 | doi=10.1016/B978-0-323-52993-8.00009-6 | pages=91–98.e3 | isbn = 9780323529938 | s2cid = 260507329 | quote=Myoglobin is not specific for myocardial necrosis, however, especially in the presence of skeletal muscle injury and [[renal insufficiency]]. }}</ref><ref name="Sekhon Peacock 2019 pp. 115–128">{{cite book | vauthors = Sekhon N, Peacock WF | title=Biomarkers in Cardiovascular Disease | chapter=Biomarkers to Assist in the Evaluation of Chest Pain | publisher=Elsevier | year=2019 | isbn=978-0-323-54835-9 | doi=10.1016/b978-0-323-54835-9.00011-9 | pages=115–128 | s2cid=59548142 | quote=myoglobin is not specific for the death of cardiac myocytes, and levels can be elevated in [[renal disease]] as well as damage to skeletal muscle.}}</ref><ref name=Nelson00>{{cite book | vauthors = Nelson DL, Cox MM | title = Lehninger Principles of Biochemistry | publisher = Worth Publishers | location = New York | year = 2000 | page = 206 | edition = 3rd | isbn = 0-7167-6203-X | url=https://books.google.com/books?id=5Ek9J4p3NfkC&q=myoglobin}} (Google books link is the 2008 edition)</ref>

High concentrations of myoglobin in muscle cells allow organisms to hold their breath for a longer period of time. Diving mammals such as whales and seals have muscles with particularly high abundance of myoglobin.<ref name=Nelson00/> Myoglobin is found in Type I muscle, Type II A, and Type II B; although many older texts describe myoglobin as not found in [[smooth muscle tissue|smooth muscle]], this has proved erroneous: there is also myoglobin in smooth muscle cells.<ref name="qiu">{{cite journal | vauthors = Qiu Y, Sutton L, Riggs AF | title = Identification of myoglobin in human smooth muscle | journal = Journal of Biological Chemistry | volume = 273 | issue = 36 | pages = 23426–32 | date = Sep 1998 | doi = 10.1074/jbc.273.36.23426 | pmid = 9722578 | doi-access = free }}</ref>

Myoglobin was the first protein to have its three-dimensional structure revealed by [[X-ray crystallography]].<ref>[https://www.nsf.gov/news/news_summ.jsp?cntn_id=100689 (U.S.) National Science Foundation: Protein Data Bank Chronology (Jan. 21, 2004)]. Retrieved 3.17.2010</ref> This achievement was reported in 1958 by [[John Kendrew]] and associates.<ref name="architecture">{{cite journal | vauthors = Kendrew JC, Bodo G, Dintzis HM, Parrish RG, Wyckoff H, Phillips DC | title = A three-dimensional model of the myoglobin molecule obtained by x-ray analysis | journal = Nature | volume = 181 | issue = 4610 | pages = 662–6 | date = Mar 1958 | pmid = 13517261 | doi = 10.1038/181662a0 | bibcode = 1958Natur.181..662K | s2cid = 4162786 }}</ref> For this discovery, Kendrew shared the 1962 [[Nobel Prize in Chemistry]] with [[Max Perutz]].<ref name="Stoddart">{{cite journal | vauthors = Stoddart C |title=Structural biology: How proteins got their close-up |journal=Knowable Magazine |date=1 March 2022 |doi=10.1146/knowable-022822-1|doi-access=free |url=https://knowablemagazine.org/article/living-world/2022/structural-biology-how-proteins-got-their-closeup |access-date=25 March 2022}}</ref><ref name="nobel">[http://nobelprize.org/chemistry/laureates/1962/index.html The Nobel Prize in Chemistry 1962]</ref> Despite being one of the most studied proteins in biology, its physiological function is not yet conclusively established: mice genetically engineered to lack myoglobin can be viable and fertile, but show many cellular and physiological adaptations to overcome the loss. Through observing these changes in myoglobin-depleted mice, it is hypothesised that myoglobin function relates to increased oxygen transport to muscle, and to oxygen storage; as well, it serves as a scavenger of [[reactive oxygen species]].<ref name="mice-function">{{cite book | vauthors = Garry DJ, Kanatous SB, Mammen PP | title = Hypoxia and the Circulation | chapter = Molecular Insights into the Functional Role of Myoglobin | series = Advances in Experimental Medicine and Biology | volume = 618 | pages = [https://archive.org/details/hypoxiacirculati00inte/page/181 181–93] | date = 2007 | publisher = Springer | pmid = 18269197 | doi = 10.1007/978-0-387-75434-5_14 | isbn = 978-0-387-75433-8 | chapter-url = https://archive.org/details/hypoxiacirculati00inte/page/181 }}</ref>

In humans, myoglobin is encoded by the ''MB'' [[gene]].<ref name="pmid2989088">{{cite journal | vauthors = Akaboshi E | title = Cloning of the human myoglobin gene | journal = Gene | volume = 33 | issue = 3 | pages = 241–9 | year = 1985 | pmid = 2989088 | doi = 10.1016/0378-1119(85)90231-8 }}</ref>

Myoglobin can take the forms oxymyoglobin (MbO<sub>2</sub>), carboxymyoglobin (MbCO), and [[metmyoglobin]] (met-Mb), analogously to hemoglobin taking the forms oxyhemoglobin (HbO<sub>2</sub>), [[carboxyhemoglobin]] (HbCO), and [[methemoglobin]] (met-Hb).<ref name="Harvey 2008 pp. 259–285">{{cite book | vauthors = Harvey JW | title=Clinical Biochemistry of Domestic Animals | chapter=Iron Metabolism and Its Disorders | publisher=Elsevier | year=2008 | isbn=978-0-12-370491-7 | doi=10.1016/b978-0-12-370491-7.00009-x | pages=259–285 | quote=Myoglobin is an oxygen-binding protein located primarily in muscles. Myoglobin serves as a local oxygen reservoir that can temporarily provide oxygen when blood oxygen delivery is insufficient during periods of intense muscular activity. Iron within the heme group must be in the Fe+2 state to bind oxygen. If iron is oxidized to the Fe+3 state, metmyoglobin is formed. }}</ref>

==Differences from hemoglobin==
Like hemoglobin, myoglobin is a cytoplasmic protein that binds oxygen on a [[heme]] group. It harbors only one globulin group, whereas hemoglobin has four. Although its heme group is identical to those in Hb, Mb has a higher affinity for oxygen than does hemoglobin but fewer total oxygen-storage capacities. Research suggests that myoglobin facilitates oxygen diffusion down a gradient, enhancing oxygen transport in mitochondria.<ref>{{cite book | vauthors = Wilson MT, Reeder BJ | chapter = Myoglobin |date=2006 | title = Encyclopedia of Respiratory Medicine |pages=73–76 | veditors = Laurent GJ, Shapiro SD |place=Oxford |publisher=Academic Press |doi=10.1016/b0-12-370879-6/00250-7 |isbn=978-0-12-370879-3 }}</ref>

==Role in cuisine==
Myoglobin contains hemes, [[pigment]]s responsible for the color of [[red meat]]. The color that meat takes is partly determined by the degree of oxidation of the myoglobin. In fresh meat the iron atom is in the ferrous (+2) oxidation state [[transition metal dioxygen complex|bound to an oxygen molecule]] (O<sub>2</sub>). Meat cooked [[well done]] is brown because the iron atom is now in the ferric (+3) oxidation state, having lost an electron. If meat has been exposed to [[nitrites]], it will remain pink, because the iron atom is bound to NO, [[nitric oxide]] (true of, e.g., [[corned beef]] or cured [[ham]]s). Grilled meats can also take on a reddish pink "smoke ring" that comes from the heme center binding to [[carbon monoxide]].<ref>{{cite book | vauthors = McGee H | title = On Food and Cooking: The Science and Lore of the Kitchen |publisher=Scribner |location=New York |year=2004 |isbn=0-684-80001-2 |page=148 }}</ref> Raw meat packed in a carbon monoxide atmosphere also shows this same pink "smoke ring" due to the same principles. Notably, the surface of this raw meat also displays the pink color, which is usually associated in consumers' minds with fresh meat. This artificially induced pink color can persist, reportedly up to one year.<ref name="pmid21844276">{{cite journal | vauthors = Fraqueza MJ, Barreto AS | title = Gas mixtures approach to improve turkey meat shelf life under modified atmosphere packaging: the effect of carbon monoxide | journal = Poultry Science | volume = 90 | issue = 9 | pages = 2076–84 | date = Sep 2011 | pmid = 21844276 | doi = 10.3382/ps.2011-01366 | doi-access = free }}</ref> [[Hormel Foods|Hormel]] and [[Cargill]] (meat processing companies in the US) are both reported to use this meat-packing process, and meat treated this way has been in the consumer market since 2003.<ref name="urlMeat companies defend use of carbon monoxide | StarTribune.com">{{cite web | url = http://www.startribune.com/business/11223451.html | title = Meat companies defend use of carbon monoxide | agency = Associated Press | date = 2007-10-30 | work = Business | publisher = Minneapolis Star Tribune | access-date = 2013-02-11 | archive-url = https://web.archive.org/web/20131225075127/http://www.startribune.com/business/11223451.html | archive-date = 2013-12-25 | url-status = dead }}</ref>

[[Meat alternative]]s have used various ways to recreate the "meaty" taste associated with myoglobin. [[Impossible Foods]] uses [[leghemoglobin]], a heme-containing globin from soy [[root nodule]], produced as a [[recombinant protein]] in ''[[Komagataella]]'' ("Pichia pastoris") yeast.<ref>{{cite journal | vauthors = Shelton K, Najera K, Ajredini S, Navarro J, Frangias T |title=The Molecular Magic of "Meatless" Meats: Structural and Sequence Similarities between Soy Leghemoglobin and Bovine Globins |journal=The FASEB Journal |date=April 2020 |volume=34 |issue=S1 |pages=1 |doi=10.1096/fasebj.2020.34.s1.04866|doi-access=free }}</ref><ref>{{cite web | vauthors = Bandoim L |date=December 20, 2019 |title=What The FDA's Decision About Soy Leghemoglobin Means For Impossible Burger |website=[[Forbes]] |url=https://www.forbes.com/sites/lanabandoim/2019/12/20/what-the-fdas-decision-about-soy-leghemoglobin-means-for-impossible-burger/#5e0a8c7457f6 |access-date=March 4, 2020}}</ref> Motif FoodWorks produces a recombinant bovine myoglobin using ''Komagataella'' yeast,<ref>{{cite web |title='A gamechanger for flavor in meat alternatives...' Motif FoodWorks to launch heme-binding protein delivering 'flavor and aroma of real meat' |url=https://www.foodnavigator-usa.com/Article/2021/09/17/Motif-FoodWorks-to-launch-myoglobin-a-yeast-derived-heme-binding-protein-delivering-the-flavor-and-aroma-of-real-meat |website=foodnavigator-usa.com |date=17 September 2021}}</ref> considered [[Generally recognized as safe|GRAS]] by the FDA.<ref>{{cite web |title=Re: GRAS Notice No. GRN 001001 |url=https://www.fda.gov/media/155001/download |archive-url=https://web.archive.org/web/20220118073310/https://www.fda.gov/media/155001/download |url-status=dead |archive-date=January 18, 2022 |website=fda.gov |date=2021-12-03}}</ref> Moolec Science has engineered a [[soybean]] that produces porcine myoglobin in its seeds called "Piggy Sooy"; it was approved by the USDA in April 2024.<ref>{{cite web |title=Moolec Becomes First Molecular Farming Company to Achieve USDA Approval for Plant-Grown Animal Proteins |url=https://finance.yahoo.com/news/moolec-becomes-first-molecular-farming-100000041.html |website=Yahoo Finance |date=22 April 2024}}</ref>

==Role in disease==
Myoglobin is released from damaged muscle tissue, which contain very high concentrations of myoglobin.<ref name="Berridge Van Vleet Herman 2013 pp. 1567–1665">{{cite book | vauthors = Berridge BR, Van Vleet JF, Herman E | title=Haschek and Rousseaux's Handbook of Toxicologic Pathology | chapter=Cardiac, Vascular, and Skeletal Muscle Systems | publisher=Elsevier | year=2013 | isbn=978-0-12-415759-0 | doi=10.1016/b978-0-12-415759-0.00046-7 | pages=1567–1665 | quote=Myoglobin is a low molecular weight oxygen binding heme protein that is found exclusively in heart and skeletal muscle cells.  In blood, myoglobin is bound primarily to plasma globulins, a complex which is filtered by the kidneys. If the plasma concentration exceeds the plasma binding capacity (1.5 mg/dl in humans), myoglobin begins to appear in the urine. High concentrations of myoglobin can change the color of the urine to a dark red-brown color.}}</ref> The released myoglobin enters the bloodstream, where high levels may indicate [[rhabdomyolysis]]. The myoglobin is filtered by the [[kidneys]], but is toxic to the renal tubular epithelium and so may cause [[acute kidney injury]].<ref name="renal">{{cite journal | vauthors = Naka T, Jones D, Baldwin I, Fealy N, Bates S, Goehl H, Morgera S, Neumayer HH, Bellomo R | title = Myoglobin clearance by super high-flux hemofiltration in a case of severe rhabdomyolysis: a case report | journal = Critical Care | volume = 9 | issue = 2 | pages = R90-5 | date = Apr 2005 | pmid = 15774055 | pmc = 1175920 | doi = 10.1186/cc3034 | doi-access = free }}</ref>  It is not the myoglobin itself that is toxic (it is a [[protoxin]]), but the ferrihemate portion that is dissociated from myoglobin in acidic environments (e.g., acidic urine, [[lysosome]]s).{{cn|date=June 2024}}

Myoglobin is a sensitive marker for muscle injury, making it a potential marker for [[myocardial infarction|heart attack]] in patients with [[chest pain]].<ref name="diagnosis">{{cite journal | vauthors = Weber M, Rau M, Madlener K, Elsaesser A, Bankovic D, Mitrovic V, Hamm C | title = Diagnostic utility of new immunoassays for the cardiac markers cTnI, myoglobin and CK-MB mass | journal = Clinical Biochemistry | volume = 38 | issue = 11 | pages = 1027–30 | date = Nov 2005 | pmid = 16125162 | doi = 10.1016/j.clinbiochem.2005.07.011 }}</ref> However, elevated myoglobin has low [[Sensitivity and specificity|specificity]] for [[myocardial infarction|acute myocardial infarction (AMI)]] and thus [[Creatine kinase|CK-MB]], [[Troponin|cardiac troponin]], [[Electrocardiogram|ECG]], and clinical signs should be taken into account to make the diagnosis.<ref name="Dasgupta Wahed 2014 pp. 127–144">{{cite book | vauthors = Dasgupta A, Wahed A | title=Clinical Chemistry, Immunology and Laboratory Quality Control | chapter=Cardiac Markers | publisher=Elsevier | year=2014 | isbn=978-0-12-407821-5 | doi=10.1016/b978-0-12-407821-5.00008-5 | pages=127–144 | quote=Myoglobin is a heme protein found in both skeletal and cardiac muscle. Myoglobin is typically released in the circulation as early as 1 h after myocardial infarction,... Myoglobin has poor clinical specificity due to the presence of large quantities of myoglobin in skeletal muscle. Some studies suggest adding the myoglobin test to the [[troponin I]] test in order to improve diagnostic value [4]. Myoglobin, being a small protein, is excreted in urine, and a high level of serum myoglobin is encountered in patients with acute renal failure ([[uremic syndrome]]). Acute renal failure is also a complication of rhabdomyolysis, ...}}</ref>

==Structure and bonding==
Myoglobin belongs to the [[globin]] superfamily of proteins, and as with other globins, consists of eight [[alpha helices]] connected by loops.  Human myoglobin contains 154 amino acids.<ref name = "P02144">{{UniProt Full|P02144}}</ref>

Myoglobin contains a [[porphyrin]] ring with an iron at its center. A ''proximal'' [[histidine]] group (His-93) is attached directly to iron, and a ''distal'' histidine group (His-64) hovers near the opposite face.<ref name = "P02144"/>  The distal imidazole is not bonded to the iron, but is available to interact with the substrate O<sub>2</sub>.  This interaction encourages the binding of O<sub>2</sub>, but not carbon monoxide (CO), which still binds about 240× more strongly than O<sub>2</sub>.{{cn|date=June 2024}}

The binding of O<sub>2</sub> causes substantial structural change at the Fe center, which shrinks in radius and moves into the center of N4 pocket.  O<sub>2</sub>-binding induces "spin-pairing": the five-coordinate ferrous deoxy form is [[high spin]] and the six coordinate oxy form is low spin and [[diamagnetic]].{{Citation needed|reason=Reliable source needed for the whole sentence|date=March 2017}}

<gallery widths="200px" heights="200px">
File:MbO2MO.png|Molecular orbital description of Fe-O<sub>2</sub> interaction in myoglobin.<ref>{{cite journal | vauthors = Drago RS | title  = Free radical reactions of transition metal systems | journal = Coordination Chemistry Reviews | year = 1980 | volume = 32 | pages = 97–110 | doi = 10.1016/S0010-8545(00)80372-0 | issue = 2 }}</ref>
File:1a6m Oxy-Myoglobin.jpg|This is an image of an oxygenated myoglobin molecule. The image shows the structural change when oxygen is bound to the iron atom of the heme prosthetic group. The oxygen atoms are colored in green, the iron atom is colored in red, and the heme group is colored in blue.
File:Myoglobine.gif|Myoglobin
</gallery>

==Synthetic analogues==
Many models of myoglobin have been synthesized as part of a broad interest in [[transition metal dioxygen complex]]es.  A well known example is the ''picket fence porphyrin'', which consists of a ferrous complex of a sterically bulky derivative of [[tetraphenylporphyrin]].<ref name="pmid1068445">{{cite journal | vauthors = Collman JP, Brauman JI, Halbert TR, Suslick KS | title = Nature of O2 and CO binding to metalloporphyrins and heme proteins | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 73 | issue = 10 | pages = 3333–7 | date = Oct 1976 | pmid = 1068445 | pmc = 431107 | doi = 10.1073/pnas.73.10.3333 | bibcode = 1976PNAS...73.3333C | doi-access = free }}</ref> In the presence of an [[imidazole]] ligand, this ferrous complex reversibly binds O<sub>2</sub>.  The O<sub>2</sub> substrate adopts a bent geometry, occupying the sixth position of the iron center.  A key property of this model is the slow formation of the μ-oxo dimer, which is an inactive diferric state.  In nature, such deactivation pathways are suppressed by protein matrix that prevents close approach of the Fe-porphyrin assemblies.<ref>{{cite book | vauthors = Lippard SJ, Berg JM | title = Principles of Bioinorganic Chemistry | publisher = University Science Books | location = Mill Valley, CA | year = 1994 | isbn = 0-935702-73-3 }}</ref>
:[[File:PicketFenceGenericRevised.png|thumb|300px|center|A picket-fence porphyrin complex of Fe, with axial coordination sites occupied by methylimidazole (green) and [[dioxygen]].  The R groups flank the O<sub>2</sub>-binding site.]]

== See also ==
* [[Cytoglobin]]
* [[Hemoglobin]]
* [[Hemoprotein]]
* [[Neuroglobin]]
* [[Phytoglobin]]
* [[Myoglobinuria]] - The presence of myoglobin in the urine
* [[Ischemia-reperfusion injury of the appendicular musculoskeletal system]]

== References ==
{{reflist|33em}}

== Further reading ==
{{refbegin|33em}}
* {{cite journal | vauthors = Collman JP, Boulatov R, Sunderland CJ, Fu L | title = Functional analogues of cytochrome c oxidase, myoglobin, and hemoglobin | journal = Chemical Reviews | volume = 104 | issue = 2 | pages = 561–88 | date = Feb 2004 | pmid = 14871135 | doi = 10.1021/cr0206059 }}
* {{cite journal | vauthors = Reeder BJ, Svistunenko DA, Cooper CE, Wilson MT | title = The radical and redox chemistry of myoglobin and hemoglobin: from in vitro studies to human pathology | journal = Antioxidants & Redox Signaling | volume = 6 | issue = 6 | pages = 954–66 | date = Dec 2004 | pmid = 15548893 | doi = 10.1089/ars.2004.6.954 }}
* {{cite journal | vauthors = Schlieper G, Kim JH, Molojavyi A, Jacoby C, Laussmann T, Flögel U, Gödecke A, Schrader J | title = Adaptation of the myoglobin knockout mouse to hypoxic stress | journal = American Journal of Physiology. Regulatory, Integrative and Comparative Physiology | volume = 286 | issue = 4 | pages = R786-92 | date = Apr 2004 | pmid = 14656764 | doi = 10.1152/ajpregu.00043.2003 | s2cid = 24831969 }}
* {{cite journal | vauthors = Takano T | title = Structure of myoglobin refined at 2-0 A resolution. II. Structure of deoxymyoglobin from sperm whale | journal = Journal of Molecular Biology | volume = 110 | issue = 3 | pages = 569–84 | date = Mar 1977 | pmid = 845960 | doi = 10.1016/S0022-2836(77)80112-5 }}
* {{cite journal | vauthors = Roy A, Sen S, Chakraborti AS | title = In vitro nonenzymatic glycation enhances the role of myoglobin as a source of oxidative stress | journal = Free Radical Research | volume = 38 | issue = 2 | pages = 139–46 | date = Feb 2004 | pmid = 15104207 | doi = 10.1080/10715160310001638038 | s2cid = 11631439 }}
* {{cite journal | vauthors = Stewart JM, Blakely JA, Karpowicz PA, Kalanxhi E, Thatcher BJ, Martin BM | title = Unusually weak oxygen binding, physical properties, partial sequence, autoxidation rate and a potential phosphorylation site of beluga whale (Delphinapterus leucas) myoglobin | journal = Comparative Biochemistry and Physiology B | volume = 137 | issue = 3 | pages = 401–12 | date = Mar 2004 | pmid = 15050527 | doi = 10.1016/j.cbpc.2004.01.007 }}
* {{cite book | vauthors = Wu G, Wainwright LM, Poole RK | title = Microbial globins | volume = 47 | pages = 255–310 | year = 2003 | pmid = 14560666 | doi = 10.1016/S0065-2911(03)47005-7 | isbn = 9780120277476 | series = Advances in Microbial Physiology }}
* {{cite journal | vauthors = Mirceta S, Signore AV, Burns JM, Cossins AR, Campbell KL, Berenbrink M | title = Evolution of mammalian diving capacity traced by myoglobin net surface charge | journal = Science | volume = 340 | issue = 6138 | pages = 1234192 | date = Jun 2013 | pmid = 23766330 | doi = 10.1126/science.1234192 | s2cid = 9644255 }}. Also see [http://proteopedia.org/wiki/index.php/Extremophile Proteopedia article about this finding]
{{Refend}}

== External links ==
* {{OMIM|160000}} human genetics
* [https://web.archive.org/web/20060623011231/http://pdbdev.sdsc.edu:48346/pdb/molecules/mb1.html RCSB PDB featured molecule]
* [https://www.nytimes.com/2006/02/21/national/21meat.html "Which Cut Is Older? (It's a Trick Question)"], ''The New York Times'', February 21, 2006 article regarding meat industry use of carbon monoxide to keep meat looking red.
* [https://www.nytimes.com/2006/03/01/dining/01meat.html "Stores React to Meat Reports"], ''The New York Times'', March 1, 2006 article on the use of carbon monoxide to make meat appear fresh.
* {{PDBe-KB2|P02144|Human Myoglobin}}

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[[Category:Hemoproteins]]
[[Category:Human proteins]]