Purification of the mitochondrial carnitine carrier by chromatography on hydroxyapatite and celite

The carnitine carrier from rat liver mitochondria has been extracted with Triton X-100 ad partially purified by chromatography on hydroxyapatite and celite. During purification the activity of the carrier was monitored by functional reconstitution into liposomes. The purified fraction is 250-fold enriched with respect to the N-ethylmaleimide-sensitive carnitine/carnitine transport activity. The substrate specificity and the inhibitor sensitivity of carnitine transport in liposomes resemble closely those described for the transport of carnitine in mitochondria.