6-Lys-met-enkephalin 6-Lysine-5-methionine-enkephalin 75909-25-0 Enkephalin-met, lys(6)- Enkephalin-met, lysine(6)- L-Lysine, N2-(N-(N-(N-(N-L-tyrosylglycyl)glycyl)-L-phenylalanyl)-L-methionyl)- Met-enk-L Met-enkephalin, lys(6)- Methionine-enkephalin, lys(6)-