PLoS ONE (Jan 2014)

Human Hsp60 with its mitochondrial import signal occurs in solution as heptamers and tetradecamers remarkably stable over a wide range of concentrations.

  • Silvia Vilasi,
  • Rita Carrotta,
  • Maria Rosalia Mangione,
  • Claudia Campanella,
  • Fabio Librizzi,
  • Loredana Randazzo,
  • Vincenzo Martorana,
  • Antonella Marino Gammazza,
  • Maria Grazia Ortore,
  • Annalisa Vilasi,
  • Gabriella Pocsfalvi,
  • Giosalba Burgio,
  • Davide Corona,
  • Antonio Palumbo Piccionello,
  • Giovanni Zummo,
  • Donatella Bulone,
  • Everly Conway de Macario,
  • Alberto J L Macario,
  • Pier Luigi San Biagio,
  • Francesco Cappello

DOI
https://doi.org/10.1371/journal.pone.0097657
Journal volume & issue
Vol. 9, no. 5
p. e97657

Abstract

Read online

It has been established that Hsp60 can accumulate in the cytosol in various pathological conditions, including cancer and chronic inflammatory diseases. Part or all of the cytosolic Hsp60 could be naïve, namely, bear the mitochondrial import signal (MIS), but neither the structure nor the in solution oligomeric organization of this cytosolic molecule has still been elucidated. Here we present a detailed study of the structure and self-organization of naïve cytosolic Hsp60 in solution. Results were obtained by different biophysical methods (light and X ray scattering, single molecule spectroscopy and hydrodynamics) that all together allowed us to assay a wide range of concentrations of Hsp60. We found that Naïve Hsp60 in aqueous solution is assembled in very stable heptamers and tetradecamers at all concentrations assayed, without any trace of monomer presence.