Catalyzes several different glutathione-dependent reactions (PubMed:8703034, PubMed:9278457, PubMed:23409838, PubMed:26656251, PubMed:26066610). Catalyzes the glutathione-dependent reduction of lipid hydroperoxides, such as 5-HPETE (PubMed:9278457, PubMed:23409838). Has glutathione transferase activity, toward xenobiotic electrophiles, such as 1-chloro-2, 4-dinitrobenzene (CDNB) (PubMed:23409838, PubMed:8703034). Catalyzes also the conjugation of leukotriene A4 with reduced glutathione to form leukotriene C4 (LTC4) (PubMed:23409838, PubMed:26656251). Involved in oxidative DNA damage induced by ER stress and anticancer agents by activating LTC4 biosynthetic machinery in nonimmune cells (PubMed:26656251). glutathione + RX = a halide anion + an S-substituted glutathione + H(+) 1-chloro-2,4-dinitrobenzene + glutathione = 2,4-dinitrophenyl-S-glutathione + chloride + H(+) leukotriene C4 = glutathione + leukotriene A4 (5S)-hydroperoxy-(6E,8Z,11Z,14Z)-eicosatetraenoate + 2 glutathione = (5S)-hydroxy-(6E,8Z,11Z,14Z)-eicosatetraenoate + glutathione disulfide + H2O Each monomer can bind on GSH molecule but only one subunit is catalytically active. kcat is 0.6 sec(-1) for leukotriene A4 as substrate (PubMed:23409838). kcat is 14.3 sec(-1) for 1-chloro-2,4-dinitrobenzene as substrate (PubMed:23409838). kcat is 0.1 sec(-1) for 5-HPETE as substrate (PubMed:23409838). Homotrimer. Liver, spleen, skeletal muscle, heart, adrenals, pancreas, prostate, testis, fetal liver, and fetal spleen. Very low expression in lung, brain, placenta and bone marrow (PubMed:8703034). Abundantly expressed in human umbilical vein endothelial cells (at protein level) (PubMed:11322876). Upon ER stress with brefeldin A or with tunicamycin, MGST2 is down-regulated, in several non-haematopoietic cell types, during the early, protective phase of the unfolded protein response (UPR), and up-regulated at the late, death-promoting phase of the unfolded protein response (UPR). Belongs to the MAPEG family.