Delineation of the functional site of alpha-dendrotoxin. The functional topographies of dendrotoxins are different but share a conserved core with those of other Kv1 potassium channel-blocking toxins.

We identified the residues that are important for the binding of alpha-dendrotoxin (alphaDTX) to Kv1 potassium channels on rat brain synaptosomal membranes, using a mutational approach based on site-directed mutagenesis and chemical synthesis. Twenty-six of its 59 residues were individually substituted by alanine. Substitutions of Lys5 and Leu9 decreased affinity more than 1000-fold, and substitutions of Arg3, Arg4, Leu6, and Ile8 by 5-30-fold.

Picosecond to hour time scale dynamics of a "three finger" toxin: correlation with its toxic and antigenic properties.

Toxin alpha from Naja nigricollis (61 amino acids, four disulfide bridges) belongs to the "three finger" fold family, which contains snake toxins with various biological activities and nontoxic proteins from different origins. In this paper, we report an extensive 1H and 15N NMR study of the dynamics of toxin alpha in solution. 15N relaxation, 1H off-resonance ROESY, and H-D exchange experiments allowed us to probe picosecond to hour motions in the protein.

High-level production and isotope labeling of snake neurotoxins, disulfide-rich proteins.

The aim of this work was to produce and to label snake neurotoxins, disulfide-rich proteins. A mutant of a snake toxin, erabutoxin a, was used as a model. Its N-terminal part was fused to ZZ, a synthetic IgG-binding domain of protein A (B.

An NMR study of the interaction of cardiotoxin gamma from Naja nigricollis with perdeuterated dodecylphosphocholine micelles.

We investigated the interaction of toxin gamma, a cardiotoxin from the venom of the elapid Naja nigricollis, with perdeuterated dodecylphosphocholine (DodPCho) micelles using standard two-dimensional proton NMR spectroscopy. The proton spectrum resonances of the micelle-bound toxin gamma were assigned, and the chemical shifts of the backbone and side-chain protons were compared with those determined in the absence of DodPCho. We observed that DodPCho induced large chemical shift changes on residues localized on the hydrophobic face of the toxin.

Genetic engineering of snake toxins. The functional site of Erabutoxin a, as delineated by site-directed mutagenesis, includes variant residues.

Using site-directed mutagenesis, we previously identified some residues that probably belong to the site by which Erabutoxin a (Ea), a sea snake toxin, recognizes the nicotinic acetylcholine receptor (AcChoR) (Pillet, L., Trémeau, O., Ducancel, F.