6i40
Crystal structure of murine neuroglobin bound to CO at 15K under illumination using optical fiber
Structural highlights
FunctionNGB_MOUSE 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] Publication Abstract from PubMedA combined biophysical approach was applied to map gas-docking sites within murine neuroglobin (Ngb), revealing snapshots of events that might govern activity and dynamics in this unique hexacoordinate globin, which is most likely to be involved in gas-sensing in the central nervous system and for which a precise mechanism of action remains to be elucidated. The application of UV-visible microspectroscopy in crystallo, solution X-ray absorption near-edge spectroscopy and X-ray diffraction experiments at 15-40 K provided the structural characterization of an Ngb photolytic intermediate by cryo-trapping and allowed direct observation of the relocation of carbon monoxide within the distal heme pocket after photodissociation. Moreover, X-ray diffraction at 100 K under a high pressure of dioxygen, a physiological ligand of Ngb, unravelled the existence of a storage site for O2 in Ngb which coincides with Xe-III, a previously described docking site for xenon or krypton. Notably, no other secondary sites were observed under our experimental conditions. Ligand pathways in neuroglobin revealed by low-temperature photodissociation and docking experiments.,Ardiccioni C, Arcovito A, Della Longa S, van der Linden P, Bourgeois D, Weik M, Montemiglio LC, Savino C, Avella G, Exertier C, Carpentier P, Prange T, Brunori M, Colloc'h N, Vallone B IUCrJ. 2019 Jul 10;6(Pt 5):832-842. doi: 10.1107/S2052252519008157. eCollection, 2019 Sep 1. PMID:31576217[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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