Sequence comparison and computer modelling of cardiotoxins and cobrotoxin isolated from Taiwan cobra.
Six cardiotoxins and one neurotoxin isolated and purified from the Taiwan cobra venom (Naja naja atra) possess distinct pharmacological and biochemical properties despite the existence of a grossly similar tertiary structure among these toxins, i. e., a core consisting of a series of short loops and four disulfide bridges. A systematic structure comparison of these major toxin isoforms was made by the secondary-structure predictions together with computer model-building based on the primary sequences and the established X-ray and NMR structures of one published cardiotoxin isoform and cobrotoxin. It is of interest to find that some defined and subtle differences can be detected upon the superposition of these three-dimensional polypeptide chains, which may reflect the intrinsic differences in the surface hydrophobicity of cardiotoxins and cobrotoxin as revealed by hydropathy profiles of these toxins in one of three major loops. The differences seem to correlate with different inhibitory activities exhibited by cardiotoxins in contrast to the lack of activity by cobrotoxin on protein kinase C (PKC).
Chiou
S H
SH
Institute of Biochemical Sciences, National Taiwan University.
Hung
C C
CC
Huang
H C
HC
Chen
S T
ST
Wang
K T
KT
Yang
C C
CC
D000595:Amino Acid Sequence; D002851:Chromatography, High Pressure Liquid; D004179:Cobra Cardiotoxin Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D003039:Cobra Neurotoxin Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D003196:Computer Graphics; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D013624:Taiwan; D014961:X-Ray Diffraction
D004179:Cobra Cardiotoxin Proteins; D003039:Cobra Neurotoxin Proteins; D009498:Neurotoxins; D011493:Protein Kinase C