Protein-glutaminase: Research progress and prospect in food manufacturing

Abstract Protein-glutaminase (PG; EC 3.5.1.44) is an enzyme that specifically catalyzes the deamidation of glutamine residues within proteins, which can be used to improve the water holding capacity and reduce allergens or unpleasant odors. Since its discovery in Chryseobacterium proteolyticum, PG has attracted widespread attention by the food industry, as it improves the protein functionality of food. However, the application of PG is still limited owing to its low enzymatic performance and yield. Recently, PG has been successfully expressed in various engineered bacterial strains to amplify its expression. This review summarizes the applications of PG in diverse industrial fields. The research and development of PG in areas such as catalytic mechanisms, molecular modification, and expression optimization, as well as the challenges and prospects for improving the performance of PG are discussed. This review provides guidance for the preparation and application of PG to improve food protein quality.