Carboxylation of pyruvate via extramitochondrial malic enzyme in rat skeletal muscle.
Soluble rat skeletal muscle extract incubated in the presence of pyruvate, NaH14CO3, MgCl2 and NADP-generating system fixed H14CO3- at the rate of about 2.3 nmol/min per mg protein. The omission of pyruvate or NADPH-generating system abolished completely the fixation of H14CO3-. This suggests that malic enzyme is responsible for the carboxylation of pyruvate. A possible role of pyruvate carboxylation by extramitochondrial malic enzyme in the conversion of lactate into glycogen in skeletal muscle is discussed.
D000818:Animals; D002458:Cell Fractionation; D005260:Female; D007521:Isocitrate Dehydrogenase / Q000378:metabolism; D007700:Kinetics; D008291:Malate Dehydrogenase / Q000378:metabolism*; D008931:Mitochondria, Muscle / Q000201:enzymology; D009132:Muscles / Q000201:enzymology*; D011773:Pyruvates / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013347:Subcellular Fractions / Q000201:enzymology
D011773:Pyruvates; D008291:Malate Dehydrogenase; D007521:Isocitrate Dehydrogenase