The cDNA encoding a variant of α bungarotoxin was cloned from the venom glands of Bungarus multicinctus by RT PCR.The deduced protein precursor contained a 21 amino acid signal peptide and a following 74 amino ...The cDNA encoding a variant of α bungarotoxin was cloned from the venom glands of Bungarus multicinctus by RT PCR.The deduced protein precursor contained a 21 amino acid signal peptide and a following 74 amino acid mature protein.The signal peptide is very similar to those of short chain neurotoxins,κ neurotoxins and cardiotoxins.The amino acid sequence of the mature protein is identical to α bungarotoxin (V31),a minor variant of α bungarotoxin identified by protein sequencing technique.Furthermore,the cDNA encoding the deletion precursor of α bungarotoxin was also cloned.By use of pMAL p2,the variant was overexpressed in E coli as a soluble fusion protein and purified by sepharose 6B amylose affinity chromatography,which was confirmed by western blotting with the antisera agai nst α bungarotoxin.The recombinant variant was achieved after digestion by factor X a.It displayed about 1/6 in vivo toxicity of natural α bungarotoxin.The successful cloning and functional expression of α bungarotoxin provided a basis for the future study of structure function of long neurotoxins.展开更多
[ Objective ] This paper aimed to obtain active alpha-bungarotoxin (α-BGT) protein and investigate the isolation and purification of recombinant α-BGT protein. [ Method] The expressed soluble fusion protein was pu...[ Objective ] This paper aimed to obtain active alpha-bungarotoxin (α-BGT) protein and investigate the isolation and purification of recombinant α-BGT protein. [ Method] The expressed soluble fusion protein was purified by using GSTrap FF affinity columns. Purified fusion protein bound to GSTrap FF affinity col- umns was directly cleaved by thrombin to obtain the solution containing recombinant α-BGT. Using natural α-BGT as control, the antigenicity and biological activity of the purified fusion protein and recombinant α-BGT were detected by SDS-PAGE, Western Blot and toxicity test in vivo. [ Result] Recombinant ot-BGT was iso- lated; the purified fusion protein and recombinant α-BGT were similar to the natural α-BGT in antigenicity; the toxicity of purified fusion protein was relatively wea- ker; recombinant α-BGT was similar to the natural ot-BGT in toxicity. [Condusion] This study laid the foundation for further large-scale production of recombi- nant α-BGT.展开更多
Nicotinic acetylcholine receptors(nAChRs) play important roles in intercellular communications of nerve cells. α-Bungarotoxins(αBtx) is a moderator for the nAChRs. Chemical synthesis provides a promising way to acce...Nicotinic acetylcholine receptors(nAChRs) play important roles in intercellular communications of nerve cells. α-Bungarotoxins(αBtx) is a moderator for the nAChRs. Chemical synthesis provides a promising way to access aBtx and their analogues. Here, we reported a new method for a-bungarotoxin by combining Fmoc-SPPS and peptide hydrazide based ligation strategy. The two-segment ligation method may enable efficient synthesis of aBtx analogues. These synthetic toxin peptides are useful tools for development of imaging or therapeutic reagents.展开更多
基金the"95"great program of Chinese Academy of Sciences! (KY95 1-A1-3 0 1-0 2 )
文摘The cDNA encoding a variant of α bungarotoxin was cloned from the venom glands of Bungarus multicinctus by RT PCR.The deduced protein precursor contained a 21 amino acid signal peptide and a following 74 amino acid mature protein.The signal peptide is very similar to those of short chain neurotoxins,κ neurotoxins and cardiotoxins.The amino acid sequence of the mature protein is identical to α bungarotoxin (V31),a minor variant of α bungarotoxin identified by protein sequencing technique.Furthermore,the cDNA encoding the deletion precursor of α bungarotoxin was also cloned.By use of pMAL p2,the variant was overexpressed in E coli as a soluble fusion protein and purified by sepharose 6B amylose affinity chromatography,which was confirmed by western blotting with the antisera agai nst α bungarotoxin.The recombinant variant was achieved after digestion by factor X a.It displayed about 1/6 in vivo toxicity of natural α bungarotoxin.The successful cloning and functional expression of α bungarotoxin provided a basis for the future study of structure function of long neurotoxins.
文摘[ Objective ] This paper aimed to obtain active alpha-bungarotoxin (α-BGT) protein and investigate the isolation and purification of recombinant α-BGT protein. [ Method] The expressed soluble fusion protein was purified by using GSTrap FF affinity columns. Purified fusion protein bound to GSTrap FF affinity col- umns was directly cleaved by thrombin to obtain the solution containing recombinant α-BGT. Using natural α-BGT as control, the antigenicity and biological activity of the purified fusion protein and recombinant α-BGT were detected by SDS-PAGE, Western Blot and toxicity test in vivo. [ Result] Recombinant ot-BGT was iso- lated; the purified fusion protein and recombinant α-BGT were similar to the natural α-BGT in antigenicity; the toxicity of purified fusion protein was relatively wea- ker; recombinant α-BGT was similar to the natural ot-BGT in toxicity. [Condusion] This study laid the foundation for further large-scale production of recombi- nant α-BGT.
基金supported by the Science and Technological Fund of Anhui Province for Outstanding Youth(No. 1808085J04)the Innovative Program Development Foundation Hefei Center Physical Science Technology(No. 2017FXCX002)
文摘Nicotinic acetylcholine receptors(nAChRs) play important roles in intercellular communications of nerve cells. α-Bungarotoxins(αBtx) is a moderator for the nAChRs. Chemical synthesis provides a promising way to access aBtx and their analogues. Here, we reported a new method for a-bungarotoxin by combining Fmoc-SPPS and peptide hydrazide based ligation strategy. The two-segment ligation method may enable efficient synthesis of aBtx analogues. These synthetic toxin peptides are useful tools for development of imaging or therapeutic reagents.