Gamma-glutamyltransferase 5 (GGT5)

Gamma-glutamyltransferase 5 (GGT5) is a cell surface enzyme of the gamma-glutamyl transpeptidase family, distinct from its paralog GGT1 by substrate specificity and tissue distribution[1][3]. GGT5 hydrolyzes the gamma-glutamyl bond of glutathione and glutathione S-conjugates, most notably converting leukotriene C4 (LTC4) to leukotriene D4 (LTD4), which is important in mediating inflammation[1][2][3]. GGT5 is widely expressed in human tissues—including macrophages in spleen, liver (Kupffer cells), lung, kidney interstitial cells, and some neurons—and supports extracellular cysteine and glutathione homeostasis, redox balance, and leukotriene-mediated signaling[1][3]. Loss or alteration of GGT5 expression affects inflammatory responses and may influence susceptibility and progression of certain diseases, such as glutathionuria and cancers (e.g., gastric cancer)[4]. It is being explored as a prognostic biomarker and potential antitumor therapeutic target[4].

Other names

Glutathione hydrolase 5 proenzymeGlutathione hydrolase 5 heavy chainGlutathione hydrolase 5 light chainGamma-glutamyl transferase 5GGTLA1GGT-relGamma-glutamyl transpeptidase-related enzymeGamma-glutamyltransferase-like activity 1Gamma-glutamyltranspeptidase 5Leukotriene-C4 hydrolaseGGL

Drugs targeting GGT5 would likely act through inhibition of gamma-glutamyl bond cleavage or modulation of leukotriene C4 metabolism; no approved drugs or tested inhibitors are documented in the references, but general mechanisms would involve blockade of its enzymatic activity[1][3].