Abstract
The synthetic lactyl anhydride isobutylcarbonyl lactyl anhydride (iBCLA), a selective and potent inhibitor of L-(+)-lactate transport in rabbit erythrocytes, reduces the chemical labeling of a 40-50-kdalton polypeptide by tritiated 4,4'-diisothiocyanato-2,2'-dihydrostilbenedisulfonate ([3H]H2DIDS). iBCLA does so in a dose-dependent manner at concentrations that strongly inhibit lactate lactate exchange but not chloride-phosphate exchange. These labeling experiments and inhibition reversal studies using iBCLA, p-(chloro-mercuri)benzenesulfonic acid (pCMBS), and dithiothreitol (DDT) suggest that iBCLA does not act at sulfhydryl groups but at or near an amino group that is near a disulfide linkage in the polypeptide which catalyzes lactate transport. These experiments support the association between specific monocarboxylate transport and a 40-50-kdalton membrane-bound polypeptide of the rabbit erythrocyte.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid
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4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / analogs & derivatives
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4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid / pharmacology
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4-Chloromercuribenzenesulfonate / pharmacology
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Animals
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Carrier Proteins / metabolism*
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Dithiothreitol / pharmacology
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Erythrocyte Membrane / drug effects
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Erythrocyte Membrane / metabolism*
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Kinetics
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Lactates / blood*
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Lactates / pharmacology*
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Lactic Acid
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Membrane Proteins / blood
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Membrane Proteins / isolation & purification
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Membrane Proteins / metabolism*
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Membrane Proteins / physiology*
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Molecular Weight
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Monocarboxylic Acid Transporters
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Rabbits
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Tritium
Substances
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Carrier Proteins
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Lactates
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Membrane Proteins
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Monocarboxylic Acid Transporters
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Tritium
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4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfonic Acid
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Lactic Acid
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4-Chloromercuribenzenesulfonate
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isobutylcarbonyllactyl anhydride
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4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid
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Dithiothreitol