4mpm
From Proteopedia
Wild-type human neuroglobin
Structural highlights
FunctionNGB_HUMAN Involved in oxygen transport in the brain. Hexacoordinate globin, displaying competitive binding of oxygen or the distal His residue to the iron atom. Not capable of penetrating cell membranes. The deoxygenated form exhibits nitrite reductase activity inhibiting cellular respiration via NO-binding to cytochrome c oxidase. Involved in neuroprotection during oxidative stress. May exert its anti-apoptotic activity by acting to reset the trigger level of mitochondrial cytochrome c release necessary to commit the cells to apoptosis.[1] [2] [3] [4] [5] Publication Abstract from PubMedNeuroglobin plays an important function in the supply of oxygen in nervous tissues. In human neuroglobin, a cysteine at position 46 in the loop connecting the C and D helices of the globin fold is presumed to form an intramolecular disulfide bond with Cys55. Rupture of this disulfide bridge stabilizes bi-histidyl haem hexacoordination, causing an overall decrease in the affinity for oxygen. Here, the first X-ray structure of wild-type human neuroglobin is reported at 1.74 A resolution. This structure provides a direct observation of two distinct conformations of the CD region containing the intramolecular disulfide link and highlights internal cavities that could be involved in ligand migration and/or are necessary to enable the conformational transition between the low and high oxygen-affinity states following S-S bond formation. The crystal structure of wild-type human brain neuroglobin reveals flexibility of the disulfide bond that regulates oxygen affinity.,Guimaraes BG, Hamdane D, Lechauve C, Marden MC, Golinelli-Pimpaneau B Acta Crystallogr D Biol Crystallogr. 2014 Apr 1;70(Pt 4):1005-14. doi:, 10.1107/S1399004714000078. Epub 2014 Mar 19. PMID:24699645[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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