Determination of mitochondrial aspartate aminotransferase in serum.
Two specific and sensitive immunoassay methods for the determination of mitochondrial aspartate aminotransferase (m-AST) are described. One is a sandwich enzyme immunoassay which measures immunologically active m-AST using polystyrene balls coated with anti-m-AST antibody and peroxidase-labelled anti-m-AST antibody as the second antibody. The detection limit of this assay was 10 micrograms/l. The other is a paper disk method which measures catalytically active enzyme bound to anti m-AST antibody-conjugate paper disks. The calibration curve was linear up to 250 U/l. These assay methods were used to monitor the level of m-AST in serum. From measurements obtained by both methods, the correlation between the concentration of m-AST protein and its activity was poor (liver diseases, r = 0.539; myocardial infarction, r = 0.774) confirming that an inactive form of m-AST exists in serum, and that the specific activity of serum m-AST differs in individual diseases.
D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood*; D003101:Collodion; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007120:Immunochemistry; D007124:Immunoenzyme Techniques; D007527:Isoenzymes / Q000097:blood*; D008107:Liver Diseases / Q000201:enzymology; D008930:Mitochondria, Liver / Q000201:enzymology*; D009203:Myocardial Infarction / Q000201:enzymology; D011817:Rabbits
D007527:Isoenzymes; D003101:Collodion; D001219:Aspartate Aminotransferases