Molecular Cloning and Expression of a New A Chain of beta-Bungarotoxin.
The cDNA encoding a new A chain of beta-bungarotoxin was cloned from Bungarus multicinctus. It encoded a 27-amino acid signal peptide and a mature protein of 120 amino acids. The mature protein had the same 13 cysteines as the other A chains and shared high homology with them. The cDNA encoding the PLA(2) from Naja naja atra was also cloned by the use of the same degenerate primers. The cDNAs encoding the new A chain and the PLA(2) were highly expressed in E. coli as soluble fusion proteins and purified by affinity chromatography. The two recombinant proteins achieved after digestion by X(a) factor showed weak and strong PLA(2) activity, respectively.
Shanghai Research Center of Biotechnology, CAS, Shanghai 200233, China. ygong@server.shcnc.ac.cn
You-Cun
YC
Qian
Chun-Yang
CY
Fan
Xiao-Long
XL
Liu
Tai-Shan
TS
Hu
Sheng-Li
SL
Yang
Yi
Y
Gong