title: Implication of lysine residues in the loss of enzymatic activity in rat liver 6-phosphogluconate dehydrogenase found in aging.
abstract: During aging, there is a decrease in the activity of the 6-phosphogluconate dehydrogenase enzyme in rat liver. The "old" 6-phosphogluconate dehydrogenase enzyme is about 26% less active than the "young" enzyme. In this paper, some biochemical and chemical properties of this enzyme are studied. 2,4,6-Trinitro-benzenesulfonic acid measurements indicate that the old enzyme has 11 lysine residues less than the young enzyme. The proteolysis with trypsin produces more peptides in the young enzyme than in the old one. However, similar numbers of peptides were produced when endoproteinase Arg-C was used on both enzymes. Moreover, the treatment of the young enzyme with ascorbate for 15 min produces the loss of 8 lysine residues. These results suggest that during aging there is a modification of the lysine residue, and this could be involved in the loss of its enzymatic activity.
authors.affiliation: Departmento de Bioquimica, Facultad de Farmacia, Universidad de Sevilla, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Gordillo
authors.forename: A
authors.initials: A
authors.lastname: Ayala
authors.forename: J
authors.initials: J
authors.lastname: Bautista
authors.forename: A
authors.initials: A
authors.lastname: Machado
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D001120:Arginine / Q000032:analysis; D001205:Ascorbic Acid; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D006639:Histidine / Q000032:analysis; D007163:Immunosorbent Techniques; D008099:Liver / Q000201:enzymology* / Q000254:growth & development; D008239:Lysine / Q000032:analysis; D008715:Methionine / Q000032:analysis; D008970:Molecular Weight; D010084:Oxidation-Reduction; D010446:Peptide Fragments / Q000302:isolation & purification; D010734:Phosphogluconate Dehydrogenase / Q000032:analysis / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013438:Sulfhydryl Compounds / Q000032:analysis
chemical_list: D010446:Peptide Fragments; D013438:Sulfhydryl Compounds; D006639:Histidine; D001120:Arginine; D008715:Methionine; D010734:Phosphogluconate Dehydrogenase; D008239:Lysine; D001205:Ascorbic Acid