Actomyosin-like Protein in Mitochondria of the Mouse Liver

Abstract

INCUBATION of mitochondria isolated from normal cells or cancer cells liberate two substances into the medium—a lipoprotein arid adenine nucleotide. When separated from the mitochondria and added to the soluble cell fraction, these have been found to exert a highly stimulating effect on glycolysis^1,2. In the case of mitochondria from normal cells, liberation of both these factors has been shown to depend on reversible changes in configuration of mitochondrial membranes. Pre-incubation of mitochondria with adenosine triphosphate, magnesium ions or ethylenediamine tetraacetic acid—that is, agents provoking shrinkage of mitochondria—proved to diminish or to prevent liberation of the stimulating factors and their retention within the mitochondria. On the contrary, pre-incubation with inorganic phosphate, calcium ions or potassium chloride, known to cause membrane relaxation and swelling of mitochondria, increased the release of the stimulating factors into the medium^1,3.