Abstracto
- The presence of multiple nicotinic acetylcholine receptor (AchR)-binding proteins and phospholipases A 2 was detected in the venom of a member of the Elapinae subfamily, Micrurus nigrocinctus nigrocinctus. Multi-step chromatographies were used to isolate four AchR-binding proteins (Mnn-9, Mnn-4, Mnn- 3C and Mnn-IA) and five basic PLA2s (nigroxins A, B, CI, C2 and C3). The Micrurus AchR-binding proteins are antigenically and structurally related to short- and long-chain a-neurotoxins from Naja. The nigroxins are antigenically similar and constitute a new antigenic subclass of PLA2s. Nigroxins A and B are class I PLA~s, structurally more related to enzymes from Bungarinae than to those from Hydrophinae/Laticaudinae. These data contribute to clarify the relationships between Micrurus venom proteins and other elapid toxins and may be useful to improve the neutralizing efficiency of antivenoms.