Cysteine proteinase inhibitors in elapid and hydrophiid snake venoms.

The ability of elapid and hydrophiid snake venoms to inhibit cathepsin L was tested. All nine species of elapid and three species of hydrophiid snake venoms tested showed inhibition against cathepsin L. All of these venoms tested also showed inhibition against papain as well as against cathepsin L. Among these venoms, two elapid (Laticauda semifasciata venom, and Ophiophagus hannah venom) and one hydrophiid snake venom (Notechis scutatus scutatus venom) showed strong inhibition against both cathepsin L and papain. These venoms contained 12.0-13.0 kDa low molecular-weight cysteine proteinase inhibitors.