"Enkephalin" . . "131330" . . . . "leucine enkephalin" . "23" . "[D-Ala², D-Leu⁵]enkephalin" . . . . . . . . . "NM_006211" . . "q" . . . "Enkephalin" . . "PENK" . . "5179" . . "8" . . "Enkephalins" . "enkephalin" . "P01210" . . . . . . "-q24" . "8831" .