Binds medium- and long-chain acyl-CoA esters with very high affinity. Can interact in vitro with oleoyl-CoA, barely with palmitoyl-CoA, but not with arachidonyl-CoA. May function as an intracellular carrier of acyl-CoA esters (By similarity). Expressed in roots, stems, leaves, flowers and siliques. Up-regulated in the light and down-regulated in constant darkness. Belongs to the ACBP family.