Purification and characterization of a neurotoxin from the venom of Ophiophagus hannah (king cobra).
A neurotoxin, Oh9-1, from the venom of Ophiophagus hannah was isolated by a combination of ion-exchange chromatography and reverse phase HPLC. Amino acid sequence analysis revealed that Oh9-1 consists of 57 amino acids and eight cysteine residues. This protein was mainly constituted with beta-sheet as evidenced by CD spectrum. Oh9-1 inhibited carbachol-induced muscle contraction in an irreversible manner and the dose for achieving 50% inhibition was approximately fourfold that of alpha-bungarotoxin. Since the residues in alpha-neurotoxins closely involve in the binding with acetylcholine receptors are not highly conserved in this toxin molecule, Oh9-1 represents a novel type of neurotoxin structurally distinct from alpha-neurotoxins.
Chang
Long-Sen
LS
Institute of Biomedical Sciences, National Sun Yat-Sen University, Kaohsiung 804, Taiwan. lschang@mail.nsysu.edu.tw
Liou
Jau-Cheng
JC
Lin
Shinne-Ren
SR
Huang
Hsien-Bin
HB
D000595:Amino Acid Sequence; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D002316:Cardiotonic Agents / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D003039:Cobra Neurotoxin Proteins / Q000032:analysis* / Q000302:isolation & purification* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004546:Elapid Venoms / Q000032:analysis* / Q000302:isolation & purification* / Q000494:pharmacology; D017815:Elapidae; D008969:Molecular Sequence Data; D009119:Muscle Contraction / Q000187:drug effects; D016415:Sequence Alignment
D002316:Cardiotonic Agents; D003039:Cobra Neurotoxin Proteins; D004546:Elapid Venoms; C459589:Oh9-1 neurotoxin; D002217:Carbachol