γ-Glutamyltransferases

Enzymes classified as EC 2.3.2.2 that transfer γ-glutamyl groups between peptides, central to glutathione metabolism and amino-acid transport. In food science they are best known as flavour enzymes: they catalyse the formation of γ-glutamyl peptides, which contribute the prized kokumi sensation, the mouthfulness and continuity that enriches the taste of aged cheeses, soy sauce, and yeast extracts. Japanese research into kokumi has made these enzymes tools for flavour enhancement, generating savoury depth without adding monosodium glutamate. They also serve as markers of liver function in clinical chemistry. Their ability to build taste-active peptides links enzymology directly with the creation of deliciousness.