(ă-mē'nō-bū-ter-āt as'id ă-mē'nō-tranz'fĕr-ās), An enzyme that catalyzes the reversible transfer of an amino group from δ-aminobutyrate to 2-oxoglutarate, thus forming an l-glutarate acid and succinate semialdehyde (an important step in the catabolism of δ-aminobutyrate).