Beschreibung:
<jats:p>Three plasma membrane subfractions have been isolated and characterized from rat liver cells. The high affinity Ca<jats:sup>2+</jats:sup>‐stimulated ATPase is highly enriched in the bile canalicular subfraction. Taking into account cross‐contamination by the blood sinusoidal and lateral membranes it is suggested that the high‐affinity Ca<jats:sup>2+</jats:sup> ‐ATPase is located exclusively in this fraction. The high‐affinity Ca<jats:sup>2+</jats:sup>‐ATPase is coupled to Ca<jats:sup>2+</jats:sup> transport, is calmodulin‐insensitive, sensitive to vanadate under appropriate experimental conditions and is strongly inhibited by La<jats:sup>3+</jats:sup>. In the presence of Ca<jats:sup>2+</jats:sup> and ATP the ATPase forms a phosphorylated intermediate of molecular mass about 200 kDa.</jats:p>