Monoclonal antibodies against subunits of yeast mitochondrial H⁺-ATPase

Fourteen stable lines of myeloma-spleen cell hybrids producing antibodies against the mitochondrial H⁺-ATPase have been isolated. One reacted with the α-subunit of the enzyme complex (M_r 56 000), nine with the β-subunit (M_r 54 000), and four with a 25 kDa subunit which has not been previously characterized. These antibodies are inhibitory or stimulatory or have no effect upon the enzyme activity. Two of the monoclonal anti-β-subunit antibodies were found to be particularly effective in immunoprecipitating intact H⁺-ATPase complex.