Purification and basic properties of the aspartate aminotransferases from a variety of sources

1. 1. The following aspartate aminotransferases have been isolated: cytosolic and mitochondrial isozymes from horse heart, rat liver and mouse liver, the mitochondrial isozyme from turkey liver, and the single isozymes from yeast and E. coli. 2. 2. Comparisons of the electrophoretic characteristics of the various isozymes are reported. In the case of the mitochondrial isozyme from turkey liver, studies have been made of the subforms of the protein and of its behaviour on hydrophobic chromatography. 3. 3. Studies of the distribution and stabilities of aspartate aminotransferase isozymes in homogenates of trout liver are reported.