The activity of pyruvate carrier in a reconstituted system: substrate specificity and inhibitor sensitivity.
The pyruvate carrier, of molecular mass 34 kDa, was purified from mitochondria isolated from rat liver, rat brain, and bovine heart, by affinity chromatography on immobilized 2-cyano-4-hydroxycinnamate. Its activity after reconstitution in phosphatidylcholine vesicles was measured either as uptake of [1-14C]pyruvate or as exchange with different 2-oxoacids. All preparations exhibited similar apparent Km values for pyruvate, but somewhat different V(max) values. The ability to exchange different anions of physiological significance, including branched-chain 2-oxoacids, confirmed the known substrate specificity described for the pyruvate carrier in mitochondria. The sensitivity of pyruvate transport toward phenylglyoxal suggested an important role of arginyl residues in the transport activity, while a role of lysyl and histidyl residues was not confirmed.
Nałecz
K A
KA
Nencki Institute of Experimental Biology, Polish Academy of Sciences, Warsaw.
Kamińska
J
J
Nałecz
M J
MJ
Azzi
A
A
D000090:Acetoacetates / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism*; D002417:Cattle; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D026901:Membrane Transport Proteins; D008928:Mitochondria / Q000201:enzymology*; D008929:Mitochondria, Heart / Q000201:enzymology*; D008930:Mitochondria, Liver / Q000201:enzymology*; D024101:Mitochondrial Proteins; D008970:Molecular Weight; D027501:Monocarboxylic Acid Transporters; D011773:Pyruvates / Q000378:metabolism*; D051381:Rats; D000070590:Solute Carrier Proteins
D000090:Acetoacetates; D002352:Carrier Proteins; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D027501:Monocarboxylic Acid Transporters; C000629174:Mpc1 protein, rat; D011773:Pyruvates; D000070590:Solute Carrier Proteins; C016635:acetoacetic acid