[The effect of antibodies against Ca2(+)-ATPase and its hydrophobic fragment on the activity of this enzyme and on the passive transport of Ca2(+)].

It is shown that both Ca(2+)-ATPase and its hydrophobic fragment are immunogenic factors. A region between hydrophobic and hydrophilic parts of Ca(2+)-ATP-ase is immunogenic. These antibodies clearly inhibit inflow and outflow of Ca2+ through a hydrophobic fragment reconstructed into liposomes and do not influence Ca(2+)-ATPase activity.