The goal is to understand the essential hydrophobic and subunit interactions with the mitochondrial electron transport system that enable it to couple electron transport to ATP synthesis. Four specific projects will probe functionally important interactions within cytochrome c oxidase, which is the terminal electron transport complexes in the inner mitochondiral membrane. The first objective will be to determine the phospholipid specificity and the functionally important high affinity lipid binding sites on cytochrome c oxidase. The approaches to be used include measurement of functional binding of synthetic derivatives of cardiolipin that contain defined abnormal fatty acid tails, and photoaffinity labeling the cardiolipin binding sites with cardiolipin analogs. The second objective will be to determine the involvement of the tightly bound cardiolipin in dimerization of cytochrome c oxidase. The techniques to be used will utilize high speed sedimentation velocity to measure the aggregation state of the protein as a function of bound cardiolipin. The third goal is to structurally locate the redox centers within the protein relative to the membrane interior and one of the protein subunits, subunit III. The approach will be measurement of intrinsic protein fluorescence. The last goal will be a direct investigation of the structure of one of the subunits of cytochrome c oxidase, subunit III. The approaches in this project utilize detergent binding methods to measure surface hydrophobicity and hydrodynamic measurements to determine overall size and shape of the purified subunit. Together, these four approaches will probe the importance of specific lipids and subunits in the structure and function of this inner mitochondiral membrane protein.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM024795-13
Application #
3272521
Study Section
Physical Biochemistry Study Section (PB)
Project Start
1978-01-01
Project End
1990-12-31
Budget Start
1990-01-01
Budget End
1990-12-31
Support Year
13
Fiscal Year
1990
Total Cost
Indirect Cost
Name
University of Texas Health Science Center San Antonio
Department
Type
Schools of Dentistry
DUNS #
800772162
City
San Antonio
State
TX
Country
United States
Zip Code
78229
Musatov, Andrey; Siposova, Katarina; Kubovcikova, Martina et al. (2016) Functional and structural evaluation of bovine heart cytochrome c oxidase incorporated into bicelles. Biochimie 121:21-8
Musatov, Andrej; Varha?, Rastislav; Hosler, Jonathan P et al. (2016) Delipidation of cytochrome c oxidase from Rhodobacter sphaeroides destabilizes its quaternary structure. Biochimie 125:23-31
Musatov, Andrej; Robinson, Neal C (2014) Bound cardiolipin is essential for cytochrome c oxidase proton translocation. Biochimie 105:159-64
Musatov, Andrej; Fabian, Marian; Varha?, Rastislav (2013) Elucidating the mechanism of ferrocytochrome c heme disruption by peroxidized cardiolipin. J Biol Inorg Chem 18:137-44
Musatov, Andrej (2013) Dual effect of heparin on Fe²?-induced cardiolipin peroxidation: implications for peroxidation of cytochrome c oxidase bound cardiolipin. J Biol Inorg Chem 18:729-37
Musatov, Andrej; Robinson, Neal C (2012) Susceptibility of mitochondrial electron-transport complexes to oxidative damage. Focus on cytochrome c oxidase. Free Radic Res 46:1313-26
Sedlak, Erik; Fabian, Marian; Robinson, Neal C et al. (2010) Ferricytochrome c protects mitochondrial cytochrome c oxidase against hydrogen peroxide-induced oxidative damage. Free Radic Biol Med 49:1574-81
Varhac, Rastislav; Robinson, Neal C; Musatov, Andrej (2009) Removal of bound Triton X-100 from purified bovine heart cytochrome bc1. Anal Biochem 395:268-70
Sedlák, Erik; Robinson, Neal C (2009) Sequential dissociation of subunits from bovine heart cytochrome C oxidase by urea. Biochemistry 48:8143-50
Lemma-Gray, Patrizia; Valusova, Eva; Carroll, Christopher A et al. (2008) Subunit analysis of bovine heart complex I by reversed-phase high-performance liquid chromatography, electrospray ionization-tandem mass spectrometry, and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry. Anal Biochem 382:116-21

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