The amino acid sequence of cobrotoxin

Yang, Chen-Chung; Yang, H.J.; Huang, Jian-Yuan

doi:10.1016/0005-2795(69)90046-4

Cited by 139 publications

(6 citation statements)

References 16 publications

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“…The SNTX transcripts NKM_FTX05 and NKT_FTX06 show amino acid sequence identical to cobrotoxin from N. atra (UniProtKB: P60770), whereas NKM_FTX06, NKT_FTX04 and NKT_FTX05 have amino acid sequences identical to cobrotoxin-c (UniProtKB: P59276) from N. kaouthia (Meng et al, 2002; Yang, Yang & Huang, 1969). It is interesting to note that all three cobrotoxins annotated (the former two transcripts, and NKM_FTX08 that is homologous to cobrotoxin-b; UniProtKB: P80958) have been previously reported in the venom of N. kaouthia from Yunnan, China (Meng et al, 2002; Qiumin et al, 2002), indicating that the cobrotoxin-encoding gene is well conserved in N. kaouthia from distant geographical regions.…”

Section: Resultsmentioning

confidence: 99%

Comparative venom gland transcriptomics ofNaja kaouthia(monocled cobra) from Malaysia and Thailand: elucidating geographical venom variation and insights into sequence novelty

Tan

Chanhome

et al. 2017

PeerJ

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BackgroundThe monocled cobra (Naja kaouthia) is a medically important venomous snake in Southeast Asia. Its venom has been shown to vary geographically in relation to venom composition and neurotoxic activity, indicating vast diversity of the toxin genes within the species. To investigate the polygenic trait of the venom and its locale-specific variation, we profiled and compared the venom gland transcriptomes of N. kaouthia from Malaysia (NK-M) and Thailand (NK-T) applying next-generation sequencing (NGS) technology.MethodsThe transcriptomes were sequenced on the Illumina HiSeq platform, assembled and followed by transcript clustering and annotations for gene expression and function. Pairwise or multiple sequence alignments were conducted on the toxin genes expressed. Substitution rates were studied for the major toxins co-expressed in NK-M and NK-T.Results and discussionThe toxin transcripts showed high redundancy (41–82% of the total mRNA expression) and comprised 23 gene families expressed in NK-M and NK-T, respectively (22 gene families were co-expressed). Among the venom genes, three-finger toxins (3FTxs) predominated in the expression, with multiple sequences noted. Comparative analysis and selection study revealed that 3FTxs are genetically conserved between the geographical specimens whilst demonstrating distinct differential expression patterns, implying gene up-regulation for selected principal toxins, or alternatively, enhanced transcript degradation or lack of transcription of certain traits. One of the striking features that elucidates the inter-geographical venom variation is the up-regulation of α-neurotoxins (constitutes ∼80.0% of toxin’s fragments per kilobase of exon model per million mapped reads (FPKM)), particularly the long-chain α-elapitoxin-Nk2a (48.3%) in NK-T but only 1.7% was noted in NK-M. Instead, short neurotoxin isoforms were up-regulated in NK-M (46.4%). Another distinct transcriptional pattern observed is the exclusively and abundantly expressed cytotoxin CTX-3 in NK-T. The findings suggested correlation with the geographical variation in proteome and toxicity of the venom, and support the call for optimising antivenom production and use in the region. Besides, the current study uncovered full and partial sequences of numerous toxin genes from N. kaouthia which have not been reported hitherto; these include N. kaouthia-specific l-amino acid oxidase (LAAO), snake venom serine protease (SVSP), cystatin, acetylcholinesterase (AChE), hyaluronidase (HYA), waprin, phospholipase B (PLB), aminopeptidase (AP), neprilysin, etc. Taken together, the findings further enrich the snake toxin database and provide deeper insights into the genetic diversity of cobra venom toxins.

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Section: Resultsmentioning

confidence: 99%

Comparative venom gland transcriptomics ofNaja kaouthia(monocled cobra) from Malaysia and Thailand: elucidating geographical venom variation and insights into sequence novelty

Tan

Chanhome

et al. 2017

PeerJ

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“…A toxin from Naja atra (Formosan cobra), cobrotoxin was sequenced by Yang. 15) The sea snakes in South Pacific and Indian Oceans are closely related. The authors worked on Australian snakes which have also similar toxins.…”

Section: Amino Acid Sequences Of Snake Toxinsmentioning

confidence: 99%

Studies on sea snake venom

Tamiya

Yagi

2011

Proceedings of the Japan Academy. Ser. B: Physical and Biologic

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Erabutoxins a and b are neurotoxins isolated from venom of a sea snake Laticauda semifasciata (erabu-umihebi). Amino acid sequences of the toxins indicated that the toxins are members of a superfamily consisting of short and long neurotoxins and cytotoxins found in sea snakes and terrestrial snakes. The short neurotoxins to which erabutoxins belong act by blocking the nicotinic acetylcholine receptor on the post synaptic membrane in a manner similar to that of curare. X-ray crystallography and NMR analyses showed that the toxins have a three-finger structure, in which three fingers made of three loops emerging from a dense core make a gently concave surface of the protein. The sequence comparison and the location of essential residues on the protein suggested the mechanism of binding of the toxin to the acetylcholine receptor. Classification of snakes by means of sequence comparison and that based on different morphological features were inconsistent, which led the authors to propose a hypothesis “Evolution without divergence.”

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“…Control measurements could be made over a 6 h period without significant change in the amplitude of the CAP and tetanus. The venom from N. naja atra was obtained from the Miami Serpentarium and the a-toxin was purified to homogeneity by ionexchange and gel chromatography [15]. Purified o~-bungarotoxin was obtained from Sigma.…”

Section: Methodsmentioning

confidence: 99%

Multiple effects of α‐toxins on the nicotinic acetylcholine receptor

Bradley¹,

Pagala²,

Edge³

1987

FEBS Letters

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Very low concentrations (5 nM) of ~-toxin from the venom of Naja naja atra produced a characteristic fade in muscle compound action potential and tetanus induced by repetitive nerve stimulation which was identical to the effects of curare. High concentrations of s-toxin and all concentrations of ~-bungarotoxin reduced the response but produced very little fade in comparison to curare. These results suggest that :t-toxins have more than one effect at the neuromuscular junction.

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The amino acid sequence of cobrotoxin

Cited by 139 publications

References 16 publications

Comparative venom gland transcriptomics ofNaja kaouthia(monocled cobra) from Malaysia and Thailand: elucidating geographical venom variation and insights into sequence novelty

Comparative venom gland transcriptomics ofNaja kaouthia(monocled cobra) from Malaysia and Thailand: elucidating geographical venom variation and insights into sequence novelty

Studies on sea snake venom

Multiple effects of α‐toxins on the nicotinic acetylcholine receptor

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