malate-aspartate shuttle
malate-aspartate shuttle
The process of transferring reducing equivalents from NADH in the cytosol to the mitochondria via malate. Cytosolic aspartate aminotransferase converts aspartate to oxaloacetate, and cytosolic malate dehydrogenase uses NADH to convert oxaloacetate to malate in the cytosol; the malate-alpha-ketoglutarate carrier then transports the malate into the mitochondria where mitochondrial malate dehydrogenase uses NAD to convert malate back to oxaloacetate; the electrons on the reduced NADH are then available for use in the electron transport chain; mitochondrial aspartate aminotransferase converts oxaloacetate to aspartate, and the glutamate-aspartate carrier transports the aspartate back to the cytosol to complete the cycle.