Calcium transport and translocation of adenine nucleotides in mitochondria from Morris hepatoma 3924A
Eboli, M.L.; Malmström, K.; Galeotti, T.; López-Alarcón, L.; Carafoli, E.
Cancer Research 39(7 Part 1): 2737-2742
1979
ISSN/ISBN: 0008-5472 PMID: 445477 Document Number: 153181
The interaction of Ca2+ with Morris hepatoma 3924A mitochondria and its effect on the adenine nucleotide translocation have been studied. The characteristics of the Ca2+ transport process in mitochondria from Morris hepatoma are not significantly different from those of normal liver mitochondria. The Km for Ca2+ is 2 to 3 microM, and the rate versus concentration curve exhibits hyperbolic kinetics. A lower activity of the adenine nucleotide translocation was found, probably due to the high endogenous Ca2+ content of Morris hepatoma mitochondria (123 +/- 15 nmol Ca2+ per mg protein). No further inhibition of the translocase activity was observed after isolated mitochondria had accumulated extra amounts of Ca2+. The total amount of adenine nucleotides in tumor mitochondria is one-half those present in control liver, and a significantly lower percentage of the pool is present as adenosine 5'-monophosphate.