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  • The EMBO Journal (2007) 26, 1713 - 1725
  • doi:10.1038/sj.emboj.7601618

Published online: 1 March 2007

Structures and physiological roles of 13 integral lipids of bovine heart cytochrome c oxidase

Kyoko Shinzawa-Itoh1,a, Hiroshi Aoyama2,a, Kazumasa Muramoto1, Hirohito Terada1, Tsuyoshi Kurauchi1, Yoshiki Tadehara1, Akiko Yamasaki3, Takashi Sugimura3, Sadamu Kurono4, Kazuo Tsujimoto4, Tsunehiro Mizushima5, Eiki Yamashita5, Tomitake Tsukihara5 and Shinya Yoshikawa1

  1. Department of Life Science, University of Hyogo, Kamigohri Akoh Hyogo, Japan
  2. RIKEN Harima Institute, Mikazuki Sayo, Hyogo, Japan
  3. Department of Material Science, University of Hyogo, Kamigohri Akoh Hyogo, Japan
  4. Graduate School of Material Science, Japan Advanced Institute of Science and Technology, Nomi Ishikawa, Japan
  5. Institute for Protein Research, Osaka University, Japan

Correspondence to:

Shinya Yoshikawa, Department of Life Science, University of Hyogo, Kamigohri Akoh Hyogo 678-1297, Japan. Tel.: +81 791 58 0190; Fax: +81 791 58 0132; E-mail: yoshi@sci.u-hyogo.ac.jp

aThese authors contributed equally to this work

Received 16 September 2006; Accepted 24 January 2007

All 13 lipids, including two cardiolipins, one phosphatidylcholine, three phosphatidylethanolamines, four phosphatidylglycerols and three triglycerides, were identified in a crystalline bovine heart cytochrome c oxidase (CcO) preparation. The chain lengths and unsaturated bond positions of the fatty acid moieties determined by mass spectrometry suggest that each lipid head group identifies its specific binding site within CcOs. The X-ray structure demonstrates that the flexibility of the fatty acid tails facilitates their effective space-filling functions and that the four phospholipids stabilize the CcO dimer. Binding of dicyclohexylcarbodiimide to the O2 transfer pathway of CcO causes two palmitate tails of phosphatidylglycerols to block the pathway, suggesting that the palmitates control the O2 transfer process.The phosphatidylglycerol with vaccenate (cis-Delta11-octadecenoate) was found in CcOs of bovine and Paracoccus denitrificans, the ancestor of mitochondrion, indicating that the vaccenate is conserved in bovine CcO in spite of the abundance of oleate (cis-Delta9-octadecenoate). The X-ray structure indicates that the protein moiety selects cis-vaccenate near the O2 transfer pathway against trans-vaccenate. These results suggest that vaccenate plays a critical role in the O2 transfer mechanism.

  • Keywords:

    • cytochrome c oxidase,
    • fatty acid structure,
    • mass spectrometry,
    • phospholipids,
    • X-ray structural analysis