Mitochondrial phosphate transport. Large scale isolation and characterization of the phosphate transport protein from beef heart mitochondria.
The phosphate transport protein from beef heart mitochondria has been purified on a large scale by hydroxylapatite chromatography in the presence of sodium dodecyl sulfate and urea. As shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (silver stain), the pure phosphate transport protein preparation consists of two protein bands (alpha and beta, ratio 1:1) with similar mobilities (34 kDa) which display identical peptide maps if fragmented with either CNBr or HCl/dimethyl sulfoxide/HBr. The complete amino acid composition of phosphate transport protein is presented. Quantitative determination of N-terminal amino acids underlines the purity of the preparation and shows for alpha and beta the identical amino-terminals H2N-Ala-Val-Glu-Glu-Glx-Tyr-. Qualitative digestion shows that carboxypeptidase A is able to release at least three amino acids from the C termini of the alpha as well as the beta band of phosphate transport protein. The nature of these two protein bands is discussed. The sum of phosphate transport protein (alpha + beta) per total mitochondrial protein amounts to 2.3% or 1.4 nmol of phosphate transport protein (34 kDa) per nmol of cytochrome b.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002268:Carboxypeptidases; D043422:Carboxypeptidases A; D002352:Carrier Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002417:Cattle; D004591:Electrophoresis, Polyacrylamide Gel; D008929:Mitochondria, Heart / Q000378:metabolism*; D000226:Mitochondrial ADP, ATP Translocases / Q000302:isolation & purification / Q000378:metabolism; D008970:Molecular Weight; D028044:Phosphate-Binding Proteins; D010710:Phosphates / Q000378:metabolism*
D000596:Amino Acids; D002352:Carrier Proteins; D028044:Phosphate-Binding Proteins; D010710:Phosphates; D000226:Mitochondrial ADP, ATP Translocases; D002268:Carboxypeptidases; D043422:Carboxypeptidases A