γ-Glutamyl hydrolases

Enzymes that hydrolyse γ-glutamyl linkages, cleaving the unusual γ-peptide bond between glutamate and another amino acid. Their most notable food-science role is in folate nutrition: dietary folates exist mainly as polyglutamates that must be trimmed to monoglutamates by intestinal γ-glutamyl hydrolase before absorption, so the enzyme’s activity directly affects folate bioavailability from foods. Plant and microbial γ-glutamyl hydrolases are studied for producing bioavailable folate forms and for modifying glutathione-related compounds. They also participate in the metabolism of glutathione, the master antioxidant peptide. Their specificity for the γ-linkage makes them precise biochemical tools in nutrition research.