The electric charge stoichiometry of calcium ion transport into respiring mitochondria has been measured, using H+- and Ca2+-sensitive electrodes to determine the number of H+ ions ejected in electroneutral exchange for Ca. In three types of system the ratio H+ ejected/Ca2+ taken up was very close to 2.0 when phosphate movements are prevented. Thus Ca is transported into respiring mitochondria in an electrogenic process in which each Ca carries 2 positive charges. The conclusion of Moyle and Mitchell (FEBS Lett. 73, 131-136, 1977) that Ca carries only one (+) charge is shown to be based on inadequate data and assumptions.
|Original language||English (US)|
|Number of pages||7|
|Journal||Biochemical and Biophysical Research Communications|
|State||Published - Aug 22 1977|
ASJC Scopus subject areas
- Molecular Biology