FRUCTATED PROTEIN IS MORE RESISTANT TO ATP-DEPENDENT PROTEOLYSIS THAN GLUCATED PROTEIN POSSIBLY AS A RESULT OF HIGHER CONTENT OF MAILLARD FLUOROPHORES

Glycation by fructose (fructation) renders bovine serum albumin more refractory to degradation by an ATP-dependent proteolytic system from reticulocytes than glycation by glucose (glucation), It appears that the decrease in the protein's susceptibility to degradation is a complex effect of the various protein-bound moities that are generated at the different stages of the Maillard reaction and not only the result of primary amino group blockage, Advanced Maillard reaction fluorescent components may induce a decrease in proteolysis, whereas the intermediate Amadori groups possibly may enhance degradation. However, the inhibitory effect on degradation of the fluorophores would predominate at higher levels of glycation, Resistance of intracellular fructated proteins to ATP-dependent degradation may lead to alterations in the function of cells with an active sorbitol pathway and, in this way, underlie the complications of diabetes. (C) 1995 Academic Press, Inc.