bims-cytox1 Biomed news
on Cytochrome oxidase subunit 1
Issue of 2018‒08‒26
one paper selected by
Gavin McStay
Staffordshire University


  1. Eur Biophys J. 2018 Aug 18.
    Feng W, Li J, Liang Y, Zhang Y, Li SJ.
      Tom40, the central component of the preprotein translocase of the mitochondrial outer membrane (TOM complex), forms the import pore that facilitates the translocation of preproteins across the outer membrane. Though the function of Tom40 has been intensively studied, the details of the interactions between presequence peptides and Tom40 remain unclear. In this study, we expressed rat Tom40 in Escherichia coli and purified it from inclusion bodies before investigating the refolded protein by fluorescence spectroscopy and circular dichroism (CD) spectroscopy. The far-UV CD spectra of the refolded Tom40 in various concentrations of urea revealed that the refolded protein has a well-defined structure consisting mainly of β-sheet. Moreover, the specific binding of presequence peptides to Tom40, which was demonstrated by fluorescence quenching, showed that the refolded purified protein is functional and that the interaction between Tom40 and presequence peptides is mainly electrostatic in nature.
    Keywords:  Interaction; Mitochondria; Presequence peptides; Refolding; Tom40
    DOI:  https://doi.org/10.1007/s00249-018-1329-8