Calcium transport and translocation of adenine nucleotides in mitochondria from Morris hepatoma 3924A.
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.
D000227:Adenine Nucleotides / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D007700:Kinetics; D008114:Liver Neoplasms, Experimental / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D008930:Mitochondria, Liver / Q000378:metabolism; D000226:Mitochondrial ADP, ATP Translocases / Q000378:metabolism*; D009713:Nucleotidyltransferases / Q000378:metabolism*; D051381:Rats; D011912:Rats, Inbred ACI
D000227:Adenine Nucleotides; D000226:Mitochondrial ADP, ATP Translocases; D009713:Nucleotidyltransferases; D002118:Calcium