caa a22 4500 605507384 CHVBK 20210128100631.0 cr unu---uuuuu 210128e20150401xx s 000 0 eng 10.1007/s00775-015-1238-6 doi (NATIONALLICENCE)springer-10.1007/s00775-015-1238-6 Immobilized cytochrome c bound to cardiolipin exhibits peculiar oxidation state-dependent axial heme ligation and catalytically reduces dioxygen [Elektronische Daten] [Antonio Ranieri, Diego Millo, Giulia Di Rocco, Gianantonio Battistuzzi, Carlo Bortolotti, Marco Borsari, Marco Sola] Mitochondrial cytochrome c (cytc) plays an important role in programmed cell death upon binding to cardiolipin (CL), a negatively charged phospholipid of the inner mitochondrial membrane (IMM). Although this binding has been thoroughly investigated in solution, little is known on the nature and reactivity of the adduct (cytc-CL) immobilized at IMM. In this work, we have studied electrochemically cytc-CL immobilized on a hydrophobic self-assembled monolayer (SAM) of decane-1-thiol. This construct would reproduce the motional restriction and the nonpolar environment experienced by cytc-CL at IMM. Surface-enhanced resonance Raman (SERR) studies allowed the axial heme iron ligands to be identified, which were found to be oxidation state dependent and differ from those of cytc-CL in solution. In particular, immobilized cytc-CL experiences an equilibrium between a low-spin (LS) 6c His/His and a high-spin (HS) 5c His/− coordination states. The former prevails in the oxidized and the latter in the reduced form. Axial coordination of the ferric heme thus differs from the (LS) 6c His/Lys and (LS) 6c His/OH− states observed in solution. Moreover, a relevant finding is that the immobilized ferrous cytc-CL is able to catalytically reduce dioxygen, likely to superoxide ion. These findings indicate that restriction of motional freedom due to interaction with the membrane is an additional factor playing in the mechanism of cytc unfolding and cytc-mediated peroxidation functional to the apoptosis cascade. SBIC, 2015 Cytochrome c nationallicence Cardiolipin nationallicence Electrochemistry nationallicence SERRS nationallicence Apoptosis nationallicence Dioxygen interaction nationallicence cytc : Cytochrome c nationallicence ycc : Recombinant untrimethylated Saccharomyces cerevisiae yeastiso-1-cytochrome c nationallicence KtoA : Recombinant untrimethylated Saccharomyces cerevisiae yeastiso-1-cytochrome c variant K72A/K73A/K79A nationallicence CL : Cardiolipin nationallicence Ranieri Antonio Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 183, 41125, Modena, Italy aut Millo Diego Department of Physics and Astronomy, LaserLaB Amsterdam, Vrije Universiteit, De Boelelaan 1083, 1081 HV, Amsterdam, The Netherlands aut Di Rocco Giulia Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 183, 41125, Modena, Italy aut Battistuzzi Gianantonio Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, via Campi 183, 41125, Modena, Italy aut Bortolotti Carlo Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 183, 41125, Modena, Italy aut Borsari Marco Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, via Campi 183, 41125, Modena, Italy aut Sola Marco Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 183, 41125, Modena, Italy aut JBIC Journal of Biological Inorganic Chemistry Springer Berlin Heidelberg 20/3(2015-04-01), 531-540 0949-8257 20:3<531 2015 20 775 https://doi.org/10.1007/s00775-015-1238-6 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00775-015-1238-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ranieri Antonio Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 183, 41125, Modena, Italy aut NATIONALLICENCE 700 1- Millo Diego Department of Physics and Astronomy, LaserLaB Amsterdam, Vrije Universiteit, De Boelelaan 1083, 1081 HV, Amsterdam, The Netherlands aut NATIONALLICENCE 700 1- Di Rocco Giulia Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 183, 41125, Modena, Italy aut NATIONALLICENCE 700 1- Battistuzzi Gianantonio Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, via Campi 183, 41125, Modena, Italy aut NATIONALLICENCE 700 1- Bortolotti Carlo Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 183, 41125, Modena, Italy aut NATIONALLICENCE 700 1- Borsari Marco Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, via Campi 183, 41125, Modena, Italy aut NATIONALLICENCE 700 1- Sola Marco Department of Life Sciences, University of Modena and Reggio Emilia, Via Campi 183, 41125, Modena, Italy aut NATIONALLICENCE 773 0- JBIC Journal of Biological Inorganic Chemistry Springer Berlin Heidelberg 20/3(2015-04-01), 531-540 0949-8257 20:3<531 2015 20 775