Preparative electrophoretic method for the purification of a hydrophobic membrane protein: Subunit c of the mitochondrial ATP synthase from rat liver

Research output: Contribution to journalArticle

11 Scopus citations


A method is described for the purification of subunit c of ATP synthase from rat liver mitochondria. After sample preparation and solvent extraction, the protein was purified to homogeneity by a single-step preparative electrophoretic procedure, using aqueous buffer and containing lithium dodecyl sulfate. The subunit is an extremely hydrophobic and insoluble protein and all solubilization attempts, using a variety of detergents, were unsuccessful except for lithium dodecyl sulfate. Buffer exchange and FPLC gel filtration removed the detergent from the purified sample, leaving the protein in a soluble form. The mammalian protein is composed of 75 amino acid residues, with a molecular mass of 7602 Da and is classified as a proteolipid. Subunit c accounts for 25 and 85% of the intralysosomal accumulation, within neurons, of storage material in juvenile and late- infantile forms of Batten's disease, respectively. This purification procedure allows access to a continuous supply of pure subunit c from a conventional source such as rat liver and preserves precious autopsy materials. The protein could be used as substrate in future proteolytic studies involving pepstatin-insensitive lysosomal proteases and for raising of more specific antibodies. The procedure could also be adapted/modified and used as a model for purifying other extremely insoluble proteins.

Original languageEnglish (US)
Pages (from-to)240-251
Number of pages12
JournalAnalytical Biochemistry
Issue number2
StatePublished - Sep 10 1999
Externally publishedYes



  • ATPase
  • FPLC
  • Mitochondria
  • Preparative electrophoresis
  • Subunit c purification

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

Cite this