Getting to the heart of mitochondrial function

Mitochondrial dysfunctions are associated with a wide range of human diseases. In an Advanced Online Publication in Nature Biotechnology, Steven Taylor and colleagues at MitoKor, San Diego, California, US, describe the characterization of the mitochondrial proteome in human hearts (Nature Biotechnology, DOI:10.1038/nbt793,18 February, 2003). The resulting database contains information on 615 distinct proteins and is the largest single-organelle proteome to be reported.

Taylor et al. purified mitochondrial proteins by sucrose gradient density fractionation followed by one-dimensional electrophoresis and high-throughput peptide mass finger printing. The protein pI values range from 4-11 and most proteins were smaller than 150 kDa. Around a fifth of the proteins are of unknown function.

The known proteins include most of the proteins involve in the oxidative phosphorylation machinery. Others include transporter and channel proteins, as well as those involved in the synthesis of RNA, DNA and proteins. There are also several...