Mitochondrial electrogenic aspartate/glutamate antiporter that favors efflux of aspartate and entry of glutamate and proton within the mitochondria as part of the malate-aspartate shuttle (PubMed:11566871). Also mediates the uptake of L-cysteinesulfinate by mitochondria in exchange of L-glutamate and proton. Can also exchange L-cysteinesulfinate with aspartate in their anionic form without any proton translocation (PubMed:11566871).