Application of atomic-force microscopy technology to a structural analysis of the mitochondrial inner membrane

Abstract

For the first time, the surface of mitoplasts (mitochondria devoid of an outer membrane) was investigated by atomic-force microscopy (AFM). AFM has revealed folds on the surface of mitoplasts with thicknesses of 30–40 nm, which coincides with that of “dry cristae” in mitochondria measured with small-angle neutron scattering and electron microscopy. These results indicate the existence of a specific system maintaining the configuration of a mitoplast membrane similar to that of the inner membrane of intact mitochondria under their swelling in hypotonic conditions. The prospects of using AFM to study the configuration of the surface of the mitochondrial inner membrane and other biological membrane systems were demonstrated.