cDNA sequence analysis and expression of the a chain of beta-bungarotoxin from Bungarus multicinctus (Taiwan banded krait).
The cDNA encoding the A chain of beta-bungarotoxin (beta-Bgt) was constructed from the cellular RNA isolated from the venom glands of Bungarus multicinctus (Taiwan banded krait). The deduced amino acid sequence encoding the A chain revealed that the determined one was different from the known A chains (A1, A2, A3 and A4). Nevertheless, the amino acid sequence and cDNA sequence of the new A chain (A5) was highly homologous with those of other A chains. The A5 chain was subcloned into the expression vector pT7-7 and transformed into BL21(DE3) E. coli strain. The expressed protein was isolated from the inclusion bodies of E. coli, and the refolded A chain was purified by reversed phase high performance liquid chromatography. The purified recombinant A chain exhibited an about 16% phospholipase activity of beta-Bgt. These results strongly suggest that the A chain is an active subunit responsible for the phospholipase activity of beta-Bgt.
Chang
L S
LS
Department of Biochemistry, Kaohsiung Medical College, Taiwan, ROC.
Wu
P F
PF
Chang
C C
CC
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002038:Bungarotoxins / Q000235:genetics* / Q000378:metabolism; D017838:Bungarus; D003001:Cloning, Molecular; D018076:DNA, Complementary; D008969:Molecular Sequence Data; D010741:Phospholipases A / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D002038:Bungarotoxins; D018076:DNA, Complementary; D010741:Phospholipases A