Cloning and expression of a potential coral snake α-neurotoxin Micrurus corallines in Escherichia coli
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| Author(s): |
Jane Oliveira de Figueiredo
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ) |
| Defense date: | 2000-05-11 |
| Examining board members: |
Paulo Lee Ho;
Ana Claudia Rasera da Silva;
Carlos Eduardo Winter
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| Advisor: | Paulo Lee Ho |
| Abstract | |
The nxh1 sequence has been isolated from a cDNA library from the coral snake Micrurus corallinus\' venom gland. The deduced protein is highly similar to known \"three finger\" α-neurotoxins, with four deduced disulfide bridges. However, the predicted protein lacks some important amino acids for the nicotinic acetylcholine receptor interaction. The potencial toxin NXH1 was expressed in E. coli in three different ways. The best results were obtained when the protein was expressed as a His-tagged fusion protein, which allowed rapid and efficient purification of the recombinant toxin. The fusion protein was used to generate a specific antiserum against NXH1. The produced antiserum, as well as the serum from Instituto Butantan, recognized in ELISA and Western blot the recombinant toxin. Besides, the anti-NXH1 serum recognized in Western Blot a single band from the venom of M. corallines but not the venom from other 10 Micrurus species. Binding experiments showed that the components from M. corallines venom bind to nicotinic acetylcholine receptor in rat muscle membranes. The anti-NXH1 serum did not inhibited the binding of the venom to the receptors. It seems that NXH1 is not an α-neurotoxin, or that the antiserum does not inhibit the binding of the native toxin to the receptor, or that the antiserum is not capable to inhibit the action of other α-neurotoxin from the venom. (AU) | |