Alternative-substrate inhibition of L-lactate transport via the monocarboxylate-specific carrier system in human erythrocytes.
The L-lactate/proton symport system of the red blood cell membrane was studied under conditions of alternative-substrate inhibition by glycolate. At constant pH of the medium glycolate caused competitive inhibition of L-lactate transport. In Lineweaver-Burk plots of 1/v against 1/[H], on the other hand, glycolate caused an uncompetitive inhibition. These observations indicate, that the monocarboxylate carrier exhibits ordered substrate binding, with the proton binding first.
D002352:Carrier Proteins / Q000037:antagonists & inhibitors*; D004912:Erythrocytes / Q000378:metabolism*; D006016:Glycolates / Q000494:pharmacology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007773:Lactates / Q000378:metabolism*; D019344:Lactic Acid; D008433:Mathematics; D027501:Monocarboxylic Acid Transporters
D002352:Carrier Proteins; D006016:Glycolates; D007773:Lactates; D027501:Monocarboxylic Acid Transporters; C031149:glycolic acid; D019344:Lactic Acid