Erabutoxin b is considered a short chain toxin made of 62 amino acids. The protein is basic and has a low molecular weight of 7000 Da. Erabutoxin b is shown here in spacefill.

In order to view erabutoxin b with out the water molecules press this button . Wireframe model helps to show the backbone of the protein. Erabutoxin b like many neurotoxins contains four disulfide bonds. These disulfide bridges have been found to be extremely important to the toxicity of the neurotoxin. There are many amino acids in erabutoxin b that are invarient in neurotoxins and cardiotoxins These amino acids are found in all neurotoxins and cardiotoxins. There are four other amino acids in erabutoxin b which are fuctionally invarient in all neurotoxins. Tyrosine 25 is buried in the protein. Nitration of this residue inactivates the toxin. Tryptophan 29 is exposed to the surface of erabutoxin b and when modified the lethal activity of the venom disappears. In cartoon structure it can be seen that erabutoxin b is an anti-parallel Beta sheet structure containing no alpha helix structures. The secondary structure connections between Beta sheets can be seen easier when it is layed out in a topology diagram. The site on erabutoxin b where it binds to the acetylcholine receptor is PRO 44 to GLY 49 .

Interestingly, the structure of erabutoxin b is extremely similar to that of erabutoxin a and alpha-cobratoxin.[7]

Back to Table of Contents