An alternative oxidase monoclonal antibody recognises a highly conserved sequence among alternative oxidase subunits

The alternative oxidase is found in the inner mitochondrial membranes of pl ants and some fungi and protists. A monoclonal antibody raised against the alternative oxidase from the aroid lily Sauromatum guttatum has been used e xtensively to detect the enzyme in these organisms. Using an immunoblotting strategy, the antibody binding site has been localised to the sequence RAD EAHHRDVNH within the soybean alternative oxidase 2 protein. Examination of sequence variants showed that A2 and residues C-terminal to H7 are required for recognition by the monoclonal antibody raised against the alternative oxidase. The recognition sequence is highly conserved among all alternative oxidase proteins and is absolutely conserved in 12 of 14 higher plant sequ ences, suggesting that this antibody will continue to be extremely useful i n studying the expression and synthesis of the alternative oxidase. (C) 199 9 Federation of European Biochemical Societies.