肌-{}-红蛋白(; Mb; MB),又稱肌-{}-紅素,是由153个胺基酸环绕中央的血基質组成的单链蛋白质。
肌紅蛋白的化学式為:C₈₀₃H₁₂₄₇O₂₂₅N₂₁₃S₄Fe ,分子量为16,700道尔顿。其对氧气的亲合力大于血红蛋白,所以在肌肉组织中有儲存氧气的功能。因為只需要一點氧分壓便可以使其對氧氣的結合力達到飽和,所以比血红蛋白更適合儲存氧氣。血基質對一氧化碳的親和力比氧氣大20,000倍,但是因為肌紅蛋白三級結構上His64(His E7)胺基酸不但可以與氧氣產生氫鍵還可以使一氧化碳偏離原來的結合時的自然狀態,在這一來一往的情形下,使得肌紅蛋白對一氧化碳的親和力只比氧氣高出200倍。由於不具有四級構造,所以不像血紅素一樣,產生協同效應。
若严重过度运动,有可能使肌细胞溶解并导致肌红蛋白进入血液,在肾脏堵住肾小管,引起肾损伤,称为横纹肌溶解症。肌细胞溶解还会释放出大量的钾,引起高钾血症。
參考文獻
延伸閱讀
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- . Also see [http://proteopedia.org/wiki/index.php/Extremophile Proteopedia article about this finding]
外部參考
- human genetics
- [http://macromoleculeinsights.com/myoglobin.php The Myoglobin Protein]
- [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)] 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] New York Times, March 1, 2006 article on the use of carbon monoxide to make meat appear fresh.
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