Multiple Molecular Forms of Avian Aldolases. VI. Enzymatic Properties and Amino Acid Composition of Chicken Liver Aldolase and Comparative Immunochemical Properties

Abstract

Several properties of pure chicken (Gallus domesticus) liver aldolase (fructose-1,6-diphosphate D-glycer-aldehyde-3-phosphate-lyase, EC 4.1.2.13) were determined. The enzyme shows a broad pH optimum peaking around pH 7.7, is stable over a wide pH range, and has a temperature coefficient Q10 of 2.3. The enzyme is stable at 48 °C for 10 min and is almost completely inactivated at 55 °C.The amino acid composition of pure chicken liver aldolase was determined. Its composition was compared with those of chicken muscle and chicken brain aldolases and with the corresponding rabbit aldolase enzymes.Antiserum was prepared against purified chicken liver aldolase and the immunological properties of aldolases from various tissues and species were examined. In the chicken, the antiserum has a very pronounced reaction with liver and kidney aldolases but only a weak cross-reaction with either the brain or the muscle enzyme. The antiserum readily cross-reacts with other avian liver aldolases (turkey and budgerigar) but not with mammalian liver aldolases (rat and rabbit).