Concomitant purification of three porcine heart mitochondrial enzymes: citrate synthase, aspartate aminotransferase, and malate dehydrogenase

Purification and comparative studies of several mitochondrial aspartate aminotransferases from avian liver

A new purification method has been developed which only exploits the chromatographic behaviour of avian liver mitochondrial aspartate aminotransferase enzymes (m-AAT), and permits a rapid isolation of the protein (4 days) in large quantities with high yield and low cost. m-AAT from turkey, chicken and quail livers have been isolated by chromatography on CM-Sepharose, Sephadex G-100 and 5' AMP-Sepharose using TEA-acetate buffer (pH 7.4), and specific activities (A.E.) of 311.6, 318.9, 320.1 I.U./mg respectively were obtained. Preparations were homogeneous as judged by various electrophoretic techniques and by size exclusion HPLC. The amino acid composition, Stokes Radius, subunit molecular weight and pI values have been determined and compared, finding no appreciable differences among them. In contrast, the absorption spectrum of the turkey enzyme differed from those of chicken and quail at both pH 7.4 and pH 5.0.

Simultaneous purification by affinity chromatography of rat liver mitochondrial aspartate aminotransferase and malate dehydrogenase and electrophoretic properties

Mitochondrial aspartate aminotransferase and malate dehydrogenase were purified to homogeneity from rat liver by the use of aspartate-coupled Sepharose, ion exchange, and Blue Sepharose chromatography. This procedure permits rapid preparation of these enzymes. The pI of each enzyme was determined and anomalous electrophoretic properties of aspartate aminotransferase were described.