Conjugation of reduced glutathione to a wide number of exogenous and endogenous hydrophobic electrophiles. This isozyme has a high catalytic efficiency with 4-hydroxyalkenals such as 4-hydroxynonenal (4-HNE). glutathione + RX = a halide anion + an S-substituted glutathione + H(+) Homodimer. Expressed at a high level in brain, placenta, and skeletal muscle and much lower in lung and liver. Belongs to the GST superfamily. Alpha family.