8iq1 | pdb_00008iq1
Crystal structure of hydrogen sulfide-bound superoxide dismutase in reduced state
Structural highlights
FunctionSODC_BOVIN Destroys radicals which are normally produced within the cells and which are toxic to biological systems. Publication Abstract from PubMedThe present study examines whether there is a mechanism beyond the current concept of post-translational modifications to regulate the function of a protein. A small gas molecule, hydrogen sulfide (H(2)S), was found to bind at active-site copper of Cu/Zn-SOD using a series of methods including radiolabeled binding assay, X-ray absorption near-edge structure (XANES), and crystallography. Such an H(2)S binding enhanced the electrostatic forces to guide the negatively charged substrate superoxide radicals to the catalytic copper ion, changed the geometry and energy of the frontier molecular orbitals of the active site, and subsequently facilitated the transfer of an electron from the superoxide radical to the catalytic copper ion and the breakage of the copper-His61 bridge. The physiological relevance of such an H(2)S effect was also examined in both in vitro and in vivo models where the cardioprotective effects of H(2)S were dependent on Cu/Zn-SOD. Hydrogen sulfide functions as a micro-modulator bound at the copper active site of Cu/Zn-SOD to regulate the catalytic activity of the enzyme.,Wu DD, Jin S, Cheng RX, Cai WJ, Xue WL, Zhang QQ, Yang LJ, Zhu Q, Li MY, Lin G, Wang YZ, Mu XP, Wang Y, Zhang IY, Zhang Q, Chen Y, Cai SY, Tan B, Li Y, Chen YQ, Zhang PJ, Sun C, Yin Y, Wang MJ, Zhu YZ, Tao BB, Zhou JH, Huang WX, Zhu YC Cell Rep. 2023 Jul 25;42(7):112750. doi: 10.1016/j.celrep.2023.112750. Epub 2023 , Jul 7. PMID:37421623[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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