9v6a

Publication Abstract from PubMed

Many structural studies have been reported for ferredoxin:NADP(+) reductase family members, but an experimental validation of the catalytic hydride and proton transfer steps through a direct detection of the involved hydrogen atoms has not been achieved so far. Here, we determined high-resolution X-ray and neutron crystal structures of NADH-cytochrome b(5) reductase, which acts as an electron supplier for various metabolic processes and mediates hydride and proton transfer reactions via its FAD and NADH cofactors. The X-ray structures identify the FADH(-)-NAD(+) and FAD-NADH complexes based on the electron densities of the hydrogen atoms bound to the cofactors. The neutron structures determined at different pD-values show a difference in the protonation state of the histidine residue in the hydrogen-bond network from FAD to the protein surface. The observation of the hydrogen atoms reveals the structural basis for the hydride and proton transfer reactions catalyzed by NADH-cytochrome b(5) reductase.

Structural basis of hydride and proton transfer reactions revealed by the detection of hydrogen atoms in mammalian NADH-cytochrome b(5) reductase.,Hirano Y, Kurihara K, Kusaka K, Ostermann A, Hikita M, Kimura S, Miki K, Tamada T Structure. 2025 Oct 30:S0969-2126(25)00393-4. doi: 10.1016/j.str.2025.10.006. PMID:41172987^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.