title: Cation binding site of cytochrome c oxidase: progress report.
abstract: Cytochrome c oxidase from bovine heart binds Ca(2+) reversibly at a specific Cation Binding Site located near the outer face of the mitochondrial membrane. Ca(2+) shifts the absorption spectrum of heme a, which allowed earlier the determination of the kinetic and equilibrium characteristics of the binding, and, as shown recently, the binding of calcium to the site inhibits cytochrome oxidase activity at low turnover rates of the enzyme [Vygodina, Т., Kirichenko, A., Konstantinov, A.A (2013). Direct Regulation of Cytochrome c Oxidase by Calcium Ions. PloS ONE 8, e74436]. This paper summarizes further progress in the studies of the Cation Binding Site in this group presenting the results to be reported at 18th EBEC Meeting in Lisbon, 2014. The paper revises specificity of the bovine oxidase Cation Binding Site for different cations, describes dependence of the Ca(2+)-induced inhibition on turnover rate of the enzyme and reports very high affinity binding of calcium with the "slow" form of cytochrome oxidase. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference. Guest Editors: Manuela Pereira and Miguel Teixeira.
authors.affiliation: A.N. Belozersky Research Institute of Physico-Chemical Biology, Moscow State University, Russia.
authors.forename: Tatiana V
authors.initials: TV
authors.lastname: Vygodina
authors.affiliation: A.N. Belozersky Research Institute of Physico-Chemical Biology, Moscow State University, Russia.
authors.forename: Anna
authors.initials: A
authors.lastname: Kirichenko
authors.affiliation: A.N. Belozersky Research Institute of Physico-Chemical Biology, Moscow State University, Russia. Electronic address: konst1949@gmail.com.
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Konstantinov
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002413:Cations, Divalent / Q000378:metabolism*; D002417:Cattle; D003576:Electron Transport Complex IV / Q000737:chemistry / Q000378:metabolism*; D008094:Lithium / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding
chemical_list: D002413:Cations, Divalent; D008094:Lithium; D003576:Electron Transport Complex IV
keywords: Calcium; Cation Binding Site; Cytochrome c oxidase; Oxidative phosphorylation; Regulation; Spectral shift