{
  "abstract": "The cytochrome bc1-complex from Rhodobacter capsulatus was investigated by protein electrochemistry and VIS/IR spectroscopy. Infrared difference spectra, which represent redoxinduced conformational changes of cofactors and their protein environment, show signals of the hemes, the quinone Q i , and small conformational changes of the protein backbone. Furthermore band features were tentatively assigned to protonated aspartic or glutamic acids involved in the redox transition of each of the b-hemes, a proline in that of the [2Fe2S] protein and an arginine in that of cytochrome bH. The midpoint potential of the [2Fe2S] protein was determined for the first time at physiological temperature to be +290 mV at pH 8.7. The reduced minus oxidized difference extinction coefficients of the α-bands of the cytochromes were calculated to 11.5 mM⁻¹ cm⁻¹, 19 mM⁻¹ cm⁻¹ and 6.7 mM⁻¹ cm⁻¹ for cytochrome c₁, bH, and bL respectively. A novel method has been developed to quantify protonation reactions of the complex during the redox reactions of its cofactors by evaluation of the buffer signals in the mid-infrared region. Values will be discussed in relation to the pHdependence of the midpoint potentials.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "name": "Frauke Baymann"
    },
    {
      "name": "D. Robertson"
    },
    {
      "name": "P. Dutton"
    },
    {
      "name": "Werner Mäntele"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ad4gz946gf1fm.bib",
  "cited_by": 46,
  "doi": "10.1021/bi990565b",
  "fulltext_url": null,
  "id": "ad4gz946gf1fm",
  "issns": [
    "0006-2960",
    "1520-4995"
  ],
  "landing_url": "https://hal.science/hal-05741402v1",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "hal",
      "0.chim"
    ],
    [
      "hal",
      "0.sdv"
    ],
    [
      "hal",
      "1.chim.othe"
    ],
    [
      "hal",
      "1.sdv.bbm"
    ],
    [
      "hal",
      "2.sdv.bbm.bc"
    ],
    [
      "openalex",
      "1312|Photosynthetic Processes and Mechanisms"
    ]
  ],
  "openalex": "W2410137063",
  "pdf_url": "https://hal.science/hal-05741402/document",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-07",
  "publisher": "American Chemical Society",
  "ris": "https://research.draconitic.com/paper/ad4gz946gf1fm.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:29Z",
      "native_id": "hal-05741402",
      "source": "hal",
      "url": "https://hal.science/hal-05741402v1"
    }
  ],
  "subjects": [
    {
      "field": "biochemistry",
      "origin": "openalex:1312|Photosynthetic Processes and Mechanisms",
      "subfield": "molecular-biology"
    }
  ],
  "title": "Electrochemical and Spectroscopic Investigations of the Cytochrome bc 1 Complex from Rhodobacter capsulatus",
  "title_text": "Electrochemical and Spectroscopic Investigations of the Cytochrome bc 1 Complex from Rhodobacter capsulatus",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:17:29Z",
  "url": "https://research.draconitic.com/paper/ad4gz946gf1fm",
  "venue": "Biochemistry",
  "versions": []
}