title: Temperature-dependent ESR and computational studies on antiferromagnetic electron transfer in the yeast NADH dehydrogenase Ndi1.
abstract: Ndi1 is a special type-II complex I nicotinamide-adenine-dinucleotide (NADH):ubiquinone (UQ) oxidoreductase in the yeast respiratory chain, with two bound UQs (UQIand UQII) mediating electron transfer from flavin cofactors to ubiquinone, in the absence of Fe-S chains. Here, we elucidate the underlying mechanism of electron transfer in Ndi1 through temperature-dependent Electron Spin Resonance (ESR) experiments in conjunction with quantum chemical calculations. It is revealed that electron transfer is mediated by antiferromagnetic (AFM) interactions between flavin-adenosine-dinucleotide (FAD) and UQIand between UQIand UQII. The π-stacking interactions among the aromatic complexes also enhance the through-space electron transfer. The FAD/UQIpair works as a rectifier converting double-electron co-transfer into sequential single-electron transfer events. The results not only expand our understanding on the observed AFM interactions among p-orbital aromatic mixed-stack in proteins, but also provide significant insights into the fabrication of materials with special magnetic properties using biological samples.
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, 230026, P. R. China. xz58@ustc.edu.cn cltian@ustc.edu.cn.
authors.forename: Kaiqi
authors.initials: K
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, P. R. China. maojunyang@tsinghua.edu.cn.
authors.forename: Wenfei
authors.initials: W
authors.lastname: Li
authors.affiliation: High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, 230031, P. R. China.
authors.forename: Lu
authors.initials: L
authors.lastname: Yu
authors.affiliation: High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, 230031, P. R. China.
authors.forename: Wei
authors.initials: W
authors.lastname: Tong
authors.affiliation: State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, P. R. China. maojunyang@tsinghua.edu.cn.
authors.forename: Yue
authors.initials: Y
authors.lastname: Feng
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, 230026, P. R. China. xz58@ustc.edu.cn cltian@ustc.edu.cn.
authors.forename: Shenglong
authors.initials: S
authors.lastname: Ling
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, 230026, P. R. China. xz58@ustc.edu.cn cltian@ustc.edu.cn.
authors.forename: Longhua
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, 230026, P. R. China. xz58@ustc.edu.cn cltian@ustc.edu.cn.
authors.forename: Xiao
authors.initials: X
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua-Peking Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084, P. R. China. maojunyang@tsinghua.edu.cn.
authors.forename: Maojun
authors.initials: M
authors.lastname: Yang
authors.affiliation: Hefei National Laboratory for Physical Sciences at Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, 230026, P. R. China. xz58@ustc.edu.cn cltian@ustc.edu.cn and High Magnetic Field Laboratory, Chinese Academy of Sciences, Hefei, 230031, P. R. China.
authors.forename: Changlin
authors.identifier: http://orcid.org/0000-0001-9315-900X
authors.initials: C
authors.lastname: Tian
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D004579:Electron Transport; D042967:Electron Transport Complex I / Q000737:chemistry / Q000378:metabolism*; D007501:Iron / Q000737:chemistry; D008280:Magnetics; D008956:Models, Chemical; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*; D013696:Temperature
chemical_list: C493237:Ndi1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D007501:Iron; D042967:Electron Transport Complex I