Redox-linked conformation change and electron transfer between monoheme c-type cytochromes and oxides

Journal Article · Thu Jun 15 04:00:00 EDT 2006 · Geochimica et Cosmochimica Acta, 70(17):4332-4342

DOI:https://doi.org/10.1016/j.gca.2006.06.1561· OSTI ID:944781

Khare, Nidhi; Lovelace, David M; Eggleston, Carrick M; Swenson, Michael; Magnuson, Timothy S

Electron transfer between redox active proteins and mineral oxides is important in a variety of natural as well as technological processes, including electron transfer from dissimilatory metal-reducing bacteria to minerals. One of the pathways that could trigger electron transfer between proteins and minerals is redox-linked conformation change. We present electrochemical evidence that mitochondrial cytochrome c (Mcc) undergoes significant conformation change upon interaction with hematite and indium-tin oxide (ITO) surfaces. The apparent adsorption-induced conformation change causes the protein to become more reducing, which makes it able to transfer electrons to the hematite conduction band. Although Mcc is not a protein thought to be involved in interaction with mineral surfaces, it shares (or can be conformed so as to share) some characteristics with multiheme outer-membrane cytochromes thought to be involved in the transfer of electrons from dissimilatory iron-reducing bacteria to ferric minerals during respiration. We present evidence that a 10.1 kDa monohoeme cytochrome isolated and purified from Acidiphilium cryptum, with properties similar to those of Mcc, also undergoes conformation change as a result of interaction with hematite surfaces.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 944781
• Report Number(s): PNNL-SA-61710; 13890; KP1504020
• Journal Information: Geochimica et Cosmochimica Acta, 70(17):4332-4342, Journal Name: Geochimica et Cosmochimica Acta, 70(17):4332-4342 Journal Issue: 17 Vol. 70; ISSN GCACAK; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
BACTERIA
CYTOCHROMES
ELECTRON TRANSFER
ELECTRONS
Environmental Molecular Sciences Laboratory
HEMATITE
OXIDES
PROTEINS
RESPIRATION