Multicatalytic proteinase activity in turtle liver: Responses to anoxia stress and recovery
Biochemistry and Molecular Biology International , Volume 38 - Issue 3 p. 445- 451
Activities of the multicatalytic proteinase complex (MPC) were detected in turtle (Trachemys scripta elegans) liver. The ratio of peptidylglutamyl-peptide bond hydrolyzing, trypsin-like, and chymotrypsin-like activities was 6:2.7:1 for the MPC partially purified by Sepharose CL-6B gel filtration. Molecular mass of the turtle liver enzyme was 940 ± 46 kD. Nondenaturing PAGE revealed a single band containing MPC activity reacting with peptide substrate. In vivo anoxia exposure (20 h submergence in N2-bubbled water) and subsequent 24 h aerobic recovery stimulated changes in liver protease activity. Peptidylglutamyl-peptide bond hydrolyzing activity of the partially purified MPC increased by 29% during aerobic recovery. Elevated MPC activity during recovery may serve to catabolize specific stress-related proteins or to remove proteins damaged by oxygen free radicals generated upon the reintroduction of oxygen.
|Anoxia tolerance, Extralysosomal proteolysis, Intracellular protein turnover, Metabolic arrest, Trachemys scripta, Turtle hepatic protein catabolism|
|Biochemistry and Molecular Biology International|
|Organisation||Department of Biology|
Willmore, W, & Storey, K. (1996). Multicatalytic proteinase activity in turtle liver: Responses to anoxia stress and recovery. Biochemistry and Molecular Biology International, 38(3), 445–451.