1-octadecanoyl-2-(9Z-octadecenoyl)-sn-glycero-3-phospho-L-serine + N-(acetyl)-sphing-4-enine => 2-(9Z-octadecenoyl)-sn-glycero-3-phospho-L-serine + 1-octadecanoyl-N-(acetyl)-sphing-4-enine
1-octadecanoyl-2-(9z-octadecenoyl)-sn-glycero-3-phospho-l-serine + n-(acetyl)-sphing-4-enine => 2-(9z-octadecenoyl)-sn-glycero-3-phospho-l-serine + 1-octadecanoyl-n-(acetyl)-sphing-4-enine