title: Conserved structural domains among species and tissues-specific differences in the mitochondrial phosphate-transport protein and the ADP/ATP carrier.
abstract: Peptide maps were generated of the CNBr-digested mitochondrial phosphate-transport protein and ADP/ATP carrier from bovine and rat heart, rat liver and blowfly flight muscle. Total mitochondrial proteins from the same sources plus pig heart were separated by SDS-polyacrylamide gel electrophoresis. The peptide maps and the total mitochondrial proteins were electroblotted onto nitrocellulose membranes and reacted with rabbit antisera raised against the purified bovine heart phosphate-transport protein and the ADP/ATP carrier. On the basis of antibody specificity, mobility in SDS-polyacrylamide gel electrophoresis, and peptide maps the following was concluded. Phosphate-transport protein alpha and phosphate-transport protein beta (pig and bovine heart) react equally with the first and also with the second of two independent phosphate-transport protein-antisera. Tissue-specific structural domains exist for both the phosphate-transport protein and the ADP/ATP carrier, i.e., one phosphate-transport protein-antiserum reacts with the phosphate-transport protein from all assayed sources, the other only with the cardiac phosphate-transport protein. These differences may reflect tissue-specific regulation of phosphate and adenine nucleotide transport. Homologies among the different species are found for the phosphate transport protein and the ADP/ATP carrier, except for the flight muscle ADP/ATP carrier. These conserved structural domains of the phosphate-transport protein may relate directly to catalytic activity. Alkylation of the purified phosphate-transport proteins and the ADP/ATP carriers by the transport inhibitor N-ethylmaleimide affects electrophoretic mobilities but not the antibody binding. Neither of the two phosphate-transport protein-antisera nor the ADP/ATP-carrier antiserum react with both phosphate transport protein and ADP/ATP carrier, even though these two proteins possess similarities in primary structure and function. Possible mechanisms for generating tissue-specific structural differences in the proteins are discussed.
mesh_terms: D000818:Animals; D000936:Antigen-Antibody Complex; D002352:Carrier Proteins / Q000235:genetics*; D002417:Cattle; D003488:Cyanogen Bromide; D004175:Diptera; D007106:Immune Sera; D008929:Mitochondria, Heart / Q000378:metabolism*; D008930:Mitochondria, Liver / Q000378:metabolism*; D008931:Mitochondria, Muscle / Q000378:metabolism*; D000226:Mitochondrial ADP, ATP Translocases / Q000235:genetics*; D009713:Nucleotidyltransferases / Q000235:genetics*; D009928:Organ Specificity; D010446:Peptide Fragments / Q000032:analysis; D028044:Phosphate-Binding Proteins; D051381:Rats; D013045:Species Specificity
chemical_list: D000936:Antigen-Antibody Complex; D002352:Carrier Proteins; D007106:Immune Sera; D010446:Peptide Fragments; D028044:Phosphate-Binding Proteins; D000226:Mitochondrial ADP, ATP Translocases; D009713:Nucleotidyltransferases; D003488:Cyanogen Bromide