Background: Protein glycation is a nonenzymatic covalent reaction between proteins and carbonyl groups resulting in protein denaturation. Results: DJ-1 is the first protein deglycase that repairs proteins from glycation by glyoxals, which constitutes most glycation damage. Conclusion: DJ-1 is a novel protein repair enzyme that protects proteins against glycation. Significance: DJ-1 deglycase activity changes our view on glycation/deglycation and DJ-1-associated Parkinsonism.