title: Postsynthetic changes of glutathione peroxidase (EC 1.11.1.9) and glutathione reductase (EC 1.6.4.2) in the ageing bovine lens.
abstract: Postsynthetic changes in the enzyme and structural proteins play an important role in the mechanisms of ageing of the lens, when development of protein aggregates and -S-S- linking occurs. Protection of the free -SH groups through the glutathione peroxidase and glutathione reductase system is a prerequisite to avoid these phenomena. Investigations on these two enzymes in young and old bovine lens tissues showed that they are themselves subjected to age-dependent modifications. With increasing age, the specific activity decreases while a simultaneous increase in heat lability occurs. This means that in the course of postsynthetic processes the stability of the conformation decreases and that finally the catalytic properties are lost.
mesh_terms: D000375:Aging; D000818:Animals; D002417:Cattle; D004355:Drug Stability; D005979:Glutathione Peroxidase / Q000378:metabolism*; D005980:Glutathione Reductase / Q000378:metabolism*; D006358:Hot Temperature; D007700:Kinetics; D007908:Lens, Crystalline / Q000201:enzymology / Q000254:growth & development*; D010544:Peroxidases / Q000378:metabolism*
chemical_list: D010544:Peroxidases; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase