Enkephalin is liberated from metorphamide and dynorphin a 1-8 by endooligopeptidase a but not by metalloendopeptiase ec 3.4.24.15 - Toffoletto, Odaly; Metters, K M; Oliveira, E B; Camargo, Antonio Carlos Martins de; Rossier, J (Biochemical Journal, 1988)