8IQ1

Crystal structure of hydrogen sulfide-bound superoxide dismutase in reduced state

Summary for 8IQ1

• Entry DOI: 10.2210/pdb8iq1/pdb
• Descriptor: Superoxide dismutase [Cu-Zn], COPPER (II) ION, ZINC ION, ... (9 entities in total)
• Functional Keywords: dimer, oxidoreductase
• Biological source: Bos taurus (cattle)
• Total number of polymer chains: 8
• Total formula weight: 127370.19

Authors

Zhou, J.H.,Huang, W.X.,Cheng, R.X.,Zhang, P.J.,Zhu, Y.C. (deposition date: 2023-03-15, release date: 2023-09-06, Last modification date: 2024-10-16)

Primary citation

Wu, D.D.,Jin, S.,Cheng, R.X.,Cai, W.J.,Xue, W.L.,Zhang, Q.Q.,Yang, L.J.,Zhu, Q.,Li, M.Y.,Lin, G.,Wang, Y.Z.,Mu, X.P.,Wang, Y.,Zhang, I.Y.,Zhang, Q.,Chen, Y.,Cai, S.Y.,Tan, B.,Li, Y.,Chen, Y.Q.,Zhang, P.J.,Sun, C.,Yin, Y.,Wang, M.J.,Zhu, Y.Z.,Tao, B.B.,Zhou, J.H.,Huang, W.X.,Zhu, Y.C.
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.
Cell Rep, 42:112750-112750, 2023

PubMed Abstract: The 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 (HS), 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 HS 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 HS effect was also examined in both in vitro and in vivo models where the cardioprotective effects of HS were dependent on Cu/Zn-SOD.

PubMed: 37421623
DOI: 10.1016/j.celrep.2023.112750

Experimental method

X-RAY DIFFRACTION (1.8 Å)