The complete amino acid sequence of the mitochondrial aspartate aminotransferase from pig heart was determined by analyses of the fragments obtained from tryptic digestion and cyanogen bromide treatment of the protein. The sequence analyzer was useful for establishing the primary structure of the N-terminal portion of the whole protein. There are 401 amino acid residues in the molecule. The sequence was compared with that of the cytoplasmic isozyme, showing 48% homology.
