Protein glycation in Saccharomyces cerevisiae. Argpyrimidine formation and methylglyoxal catabolism.

摘要: Methylglyoxal is the most important intracellular glycation agent, formed nonenzymatically from triose phosphates during glycolysis in eukaryotic cells. Methylglyoxal-derived advanced end-products are involved neurodegenerative disorders (Alzheimer's, Parkinson's and familial amyloidotic polyneurophathy) clinical complications of diabetes. Research models for investigating protein its relationship to methylglyoxal metabolism required understand this process, implications cell biochemistry their role human diseases. We investigated Saccharomyces cerevisiae. Using a specific antibody against argpyrimidine, marker by methylglyoxal, we found that yeast cells growing on d-glucose (100 mm) present several glycated proteins at stationary phase growth. Intracellular concentration, determined HPLC based assay, directly related argpyrimidine formation. Moreover, exposing nongrowing higher concentration (250 mm) increases formation rate modified appear within 1 h. A kinetic model yeast, comprising nonenzymatic enzymatic catabolism glutathione dependent glyoxalase pathway aldose reductase, was used probe each system parameter steady-state concentration. Sensitivity analysis studies with gene deletion mutant strains showed reductase equally preventing