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Spider Venom: Components, Modes of Action, and Novel Strategies in Transcriptomic and Proteomic Analyses. Toxins (Basel) 2019; 11:toxins11100611. [PMID: 31652611 PMCID: PMC6832493 DOI: 10.3390/toxins11100611] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 10/18/2019] [Indexed: 12/19/2022] Open
Abstract
This review gives an overview on the development of research on spider venoms with a focus on structure and function of venom components and techniques of analysis. Major venom component groups are small molecular mass compounds, antimicrobial (also called cytolytic, or cationic) peptides (only in some spider families), cysteine-rich (neurotoxic) peptides, and enzymes and proteins. Cysteine-rich peptides are reviewed with respect to various structural motifs, their targets (ion channels, membrane receptors), nomenclature, and molecular binding. We further describe the latest findings concerning the maturation of antimicrobial, and cysteine-rich peptides that are in most known cases expressed as propeptide-containing precursors. Today, venom research, increasingly employs transcriptomic and mass spectrometric techniques. Pros and cons of venom gland transcriptome analysis with Sanger, 454, and Illumina sequencing are discussed and an overview on so far published transcriptome studies is given. In this respect, we also discuss the only recently described cross contamination arising from multiplexing in Illumina sequencing and its possible impacts on venom studies. High throughput mass spectrometric analysis of venom proteomes (bottom-up, top-down) are reviewed.
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µ-TRTX-Ca1a: a novel neurotoxin from Cyriopagopus albostriatus with analgesic effects. Acta Pharmacol Sin 2019; 40:859-866. [PMID: 30382183 DOI: 10.1038/s41401-018-0181-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 09/30/2018] [Indexed: 12/16/2022] Open
Abstract
Human genetic and pharmacological studies have demonstrated that voltage-gated sodium channels (VGSCs) are promising therapeutic targets for the treatment of pain. Spider venom contains many toxins that modulate the activity of VGSCs. To date, only 0.01% of such spider toxins has been explored, and thus there is a great potential for discovery of novel VGSC modulators as useful pharmacological tools or potential therapeutics. In the current study, we identified a novel peptide, µ-TRTX-Ca1a (Ca1a), in the venom of the tarantula Cyriopagopus albostriatus. This peptide consisted of 38 residues, including 6 cysteines, i.e. IFECSISCEIEKEGNGKKCKPKKCKGGWKCKFNICVKV. In HEK293T or ND7/23 cells expressing mammalian VGSCs, this peptide exhibited the strongest inhibitory activity on Nav1.7 (IC50 378 nM), followed by Nav1.6 (IC50 547 nM), Nav1.2 (IC50 728 nM), Nav1.3 (IC50 2.2 µM) and Nav1.4 (IC50 3.2 µM), and produced negligible inhibitory effect on Nav1.5, Nav1.8, and Nav1.9, even at high concentrations of up to 10 µM. Furthermore, this peptide did not significantly affect the activation and inactivation of Nav1.7. Using site-directed mutagenesis of Nav1.7 and Nav1.4, we revealed that its binding site was localized to the DIIS3-S4 linker region involving the D816 and E818 residues. In three different mouse models of pain, pretreatment with Cala (100, 200, 500 µg/kg) dose-dependently suppressed the nociceptive responses induced by formalin, acetic acid or heat. These results suggest that Ca1a is a novel neurotoxin against VGSCs and has a potential to be developed as a novel analgesic.
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Abstract
Over a period of more than 300 million years, spiders have evolved complex venoms containing an extraordinary array of toxins for prey capture and defense against predators. The major components of most spider venoms are small disulfide-bridged peptides that are highly stable and resistant to proteolytic degradation. Moreover, many of these peptides have high specificity and potency toward molecular targets of therapeutic importance. This unique combination of bioactivity and stability has made spider-venom peptides valuable both as pharmacological tools and as leads for drug development. This review describes recent advances in spider-venom-based drug discovery pipelines. We discuss spider-venom-derived peptides that are currently under investigation for treatment of a diverse range of pathologies including pain, stroke and cancer.
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Zhang YY, Huang Y, He QZ, Luo J, Zhu L, Lu SS, Liu JY, Huang PF, Zeng XZ, Liang SP. Structural and Functional Diversity of Peptide Toxins from Tarantula Haplopelma hainanum (Ornithoctonus hainana) Venom Revealed by Transcriptomic, Peptidomic, and Patch Clamp Approaches. J Biol Chem 2015; 290:14192-207. [PMID: 25770214 DOI: 10.1074/jbc.m114.635458] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Indexed: 11/06/2022] Open
Abstract
Spider venom is a complex mixture of bioactive peptides to subdue their prey. Early estimates suggested that over 400 venom peptides are produced per species. In order to investigate the mechanisms responsible for this impressive diversity, transcriptomics based on second generation high throughput sequencing was combined with peptidomic assays to characterize the venom of the tarantula Haplopelma hainanum. The genes expressed in the venom glands were identified, and the bioactivity of their protein products was analyzed using the patch clamp technique. A total of 1,136 potential toxin precursors were identified that clustered into 90 toxin groups, of which 72 were novel. The toxin peptides clustered into 20 cysteine scaffolds that included between 4 and 12 cysteines, and 14 of these groups were newly identified in this spider. Highly abundant toxin peptide transcripts were present and resulted from hypermutation and/or fragment insertion/deletion. In combination with variable post-translational modifications, this genetic variability explained how a limited set of genes can generate hundreds of toxin peptides in venom glands. Furthermore, the intraspecies venom variability illustrated the dynamic nature of spider venom and revealed how complex components work together to generate diverse bioactivities that facilitate adaptation to changing environments, types of prey, and milking regimes in captivity.
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Affiliation(s)
- Yi-Ya Zhang
- From the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China and
| | - Yong Huang
- the State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, 20 Dong-Da Street, Fengtai District, Beijing 100071, China
| | - Quan-Ze He
- From the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China and
| | - Ji Luo
- From the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China and
| | - Li Zhu
- From the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China and
| | - Shan-Shan Lu
- From the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China and
| | - Jin-Yan Liu
- From the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China and
| | - Peng-Fei Huang
- From the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China and
| | - Xiong-Zhi Zeng
- From the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China and
| | - Song-Ping Liang
- From the Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China and
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Sermadiras I, Revell J, Linley JE, Sandercock A, Ravn P. Recombinant expression and in vitro characterisation of active Huwentoxin-IV. PLoS One 2013; 8:e83202. [PMID: 24324842 PMCID: PMC3855799 DOI: 10.1371/journal.pone.0083202] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 10/31/2013] [Indexed: 02/06/2023] Open
Abstract
Huwentoxin-IV (HwTx-IV) is a 35-residue neurotoxin peptide with potential application as a novel analgesic. It is a member of the inhibitory cystine knot (ICK) peptide family, characterised by a compact globular structure maintained by three intramolecular disulfide bonds. Here we describe a novel strategy for producing non-tagged, fully folded ICK-toxin in a bacterial system. HwTx-IV was expressed as a cleavable fusion to small ubiquitin-related modifier (SUMO) in the cytoplasm of the SHuffle T7 Express lysY Escherichia coli strain, which allows cytosolic disulfide bond formation. Purification by IMAC with selective elution of monomeric SUMO fusion followed by proteolytic cleavage and polishing chromatographic steps yielded pure homogeneous toxin. Recombinant HwTx-IV is produced with a C-terminal acid, whereas the native peptide is C-terminally amidated. HwTx-IV(acid) inhibited Nav1.7 in a dose dependent manner (IC50 = 463-727 nM). In comparison to HwTx-IV(amide) (IC50 = 11 ± 3 nM), the carboxylate was ~50 fold less potent on Nav1.7, which highlights the impact of the C-terminus. As the amide bond of an additional amino acid may mimic the carboxamide, we expressed the glycine-extended analogue HwTx-IV(G36)(acid) in the SUMO/SHuffle system. The peptide was approximately three fold more potent on Nav1.7 in comparison to HwTx-IV(acid) (IC50 = 190 nM). In conclusion, we have established a novel system for expression and purification of fully folded and active HwTx-IV(acid) in bacteria, which could be applicable to other structurally complex and cysteine rich peptides. Furthermore, we discovered that glycine extension of HwTx-IV(acid) restores some of the potency of the native carboxamide. This finding may also apply to other C-terminally amidated peptides produced recombinantly.
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Affiliation(s)
- Isabelle Sermadiras
- Antibody Discovery and Protein Engineering, Research, MedImmune, Cambridge, United Kingdom
- * E-mail:
| | - Jefferson Revell
- Antibody Discovery and Protein Engineering, Research, MedImmune, Cambridge, United Kingdom
| | - John E. Linley
- Neuroscience in vitro Biology, Research, MedImmune, Cambridge, United Kingdom
| | - Alan Sandercock
- Antibody Discovery and Protein Engineering, Research, MedImmune, Cambridge, United Kingdom
| | - Peter Ravn
- Antibody Discovery and Protein Engineering, Research, MedImmune, Cambridge, United Kingdom
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Abstract
The ICK (inhibitor cystine knot) defines a large superfamily of polypeptides with high structural stability and functional diversity. Here, we describe a new scorpion venom-derived K+ channel toxin (named λ-MeuKTx-1) with an ICK fold through gene cloning, chemical synthesis, nuclear magnetic resonance spectroscopy, Ca2+ release measurements and electrophysiological recordings. λ-MeuKTx-1 was found to adopt an ICK fold that contains a three-strand anti-parallel β-sheet and a 310-helix. Functionally, this peptide selectively inhibits the Drosophila Shaker K+ channel but is not capable of activating skeletal-type Ca2+ release channels/ryanodine receptors, which is remarkably different from the previously known scorpion venom ICK peptides. The removal of two C-terminal residues of λ-MeuKTx-1 led to the loss of the inhibitory activity on the channel, whereas the C-terminal amidation resulted in the emergence of activity on four mammalian K+ channels accompanied by the loss of activity on the Shaker channel. A combination of structural and pharmacological data allows the recognition of three putative functional sites involved in channel blockade of λ-MeuKTx-1. The presence of a functional dyad in λ-MeuKTx-1 supports functional convergence among scorpion venom peptides with different folds. Furthermore, similarities in precursor organization, exon–intron structure, 3D-fold and function suggest that scorpion venom ICK-type K+ channel inhibitors and Ca2+ release channel activators share a common ancestor and their divergence occurs after speciation between buthidae and non-buthids. The structural and functional characterizations of the first scorpion venom ICK toxin with K+ channel-blocking activity sheds light on functionally divergent and convergent evolution of this conserved scaffold of ancient origin.
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Schwartz EF, Mourão CBF, Moreira KG, Camargos TS, Mortari MR. Arthropod venoms: A vast arsenal of insecticidal neuropeptides. Biopolymers 2012. [DOI: 10.1002/bip.22100] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Meng E, Cai TF, Li WY, Zhang H, Liu YB, Peng K, Liang S, Zhang DY. Functional expression of spider neurotoxic peptide huwentoxin-I in E. coli. PLoS One 2011; 6:e21608. [PMID: 21731778 PMCID: PMC3121796 DOI: 10.1371/journal.pone.0021608] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2011] [Accepted: 06/03/2011] [Indexed: 11/18/2022] Open
Abstract
The coding sequence of huwentoxin-I, a neurotoxic peptide isolated from the venom of the Chinese spider Ornithoctonus huwena, was amplified by PCR using the cDNA library constructed from the spider venom glands. The cloned fragment was inserted into the expression vector pET-40b and transformed into the E. coli strain BL21 (DE3). The expression of a soluble fusion protein, disulfide interchange protein (DsbC)-huwentoxin-I, was auto-induced in the periplasm of E. coli in the absence of IPTG. After partial purification using a Ni-NTA column, the expressed fusion protein was digested using enterokinase to release heteroexpressed huwentoxin-I and was further purified using RP-HPLC. The resulting peptide was subjected to gel electrophoresis and mass spectrometry analysis. The molecular weight of the heteroexpressed huwentoxin-I was 3750.69, which is identical to that of the natural form of the peptide isolated from spider venom. The physiological properties of the heteroexpressed huwentoxin-I were further analyzed using a whole-cell patch clamp assay. The heteroexpressed huwentoxin-I was able to block currents generated by human Na(v1.7) at an IC₅₀ of 640 nmole/L, similar to that of the natural huwentoxin-I, which is 630 nmole/L.
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Affiliation(s)
- Er Meng
- Key Laboratory of Protein Chemistry and Developmental Biology of the Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
- Research Center of Biological Information, College of Science, National University of Defense Technology, Changsha, Hunan, China
| | - Tian-Fu Cai
- Key Laboratory of Protein Chemistry and Developmental Biology of the Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
| | - Wen-Ying Li
- Research Center of Biological Information, College of Science, National University of Defense Technology, Changsha, Hunan, China
| | - Hui Zhang
- Key Laboratory of Protein Chemistry and Developmental Biology of the Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
| | - Yan-Bo Liu
- Key Laboratory of Protein Chemistry and Developmental Biology of the Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
| | - Kuan Peng
- Core Facilities of Biotechnology, Central South University of Forestry and Technology, Changsha, Hunan, China
| | - Songping Liang
- Key Laboratory of Protein Chemistry and Developmental Biology of the Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, Hunan, China
- * E-mail: (SL); (DYZ)
| | - Dong-Yi Zhang
- Research Center of Biological Information, College of Science, National University of Defense Technology, Changsha, Hunan, China
- * E-mail: (SL); (DYZ)
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A bivalent tarantula toxin activates the capsaicin receptor, TRPV1, by targeting the outer pore domain. Cell 2010; 141:834-45. [PMID: 20510930 DOI: 10.1016/j.cell.2010.03.052] [Citation(s) in RCA: 238] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Revised: 01/12/2010] [Accepted: 03/30/2010] [Indexed: 11/22/2022]
Abstract
Toxins have evolved to target regions of membrane ion channels that underlie ligand binding, gating, or ion permeation, and have thus served as invaluable tools for probing channel structure and function. Here, we describe a peptide toxin from the Earth Tiger tarantula that selectively and irreversibly activates the capsaicin- and heat-sensitive channel, TRPV1. This high-avidity interaction derives from a unique tandem repeat structure of the toxin that endows it with an antibody-like bivalency. The "double-knot" toxin traps TRPV1 in the open state by interacting with residues in the presumptive pore-forming region of the channel, highlighting the importance of conformational changes in the outer pore region of TRP channels during activation.
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Jiang L, Zhang D, Zhang Y, Peng L, Chen J, Liang S. Venomics of the spider Ornithoctonus huwena based on transcriptomic versus proteomic analysis. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2010; 5:81-8. [PMID: 20403776 DOI: 10.1016/j.cbd.2010.01.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2009] [Revised: 01/07/2010] [Accepted: 01/07/2010] [Indexed: 10/19/2022]
Abstract
The spider Ornithoctonus huwena is a venomous spider found in southern China. Its venom is a complex mixture of numerous biologically active components. In this study, 41 novel unique transcripts encoding cellular proteins or other possible venom components were generated from the previously constructed cDNA library. These proteins were also annotated by KOG (eukaryotic orthologous group) and GO (gene ontology) terms. A novel cellular transcript contig encoding an EF-hand protein (named HWEFHP1) was found, which might be involved in the secretion of toxins in the venom glands. In order to have an overview of the molecular diversity of the O. huwena venom, the datasets of all the transcripts, peptides and proteins known so far were analyzed. A comparison of the data obtained through a proteomic versus a transcriptomic approach, revealed that only 15 putative cystine knot toxins (CKTs) were identified by both approaches, 29 transcripts coding for CKTs were found in the transcriptome but not as translated peptides in the venom proteome. However, no cellular protein with identical molecular weight was identified by both approaches. Our data may contribute to a deeper understanding of the biology and ecology of O. huwena and the relationship between structure and function of individual toxins.
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The Expression of a Recombinant cry1Ac Gene with Subtilisin-Like Protease CDEP2 Gene in Acrystalliferous Bacillus thuringiensis by Red/ET Homologous Recombination. Curr Microbiol 2009; 59:386-92. [DOI: 10.1007/s00284-009-9449-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2009] [Revised: 05/18/2009] [Accepted: 06/18/2009] [Indexed: 10/20/2022]
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Chen J, Zhang Y, Rong M, Zhao L, Jiang L, Zhang D, Wang M, Xiao Y, Liang S. Expression and characterization of jingzhaotoxin-34, a novel neurotoxin from the venom of the tarantula Chilobrachys jingzhao. Peptides 2009; 30:1042-8. [PMID: 19463735 DOI: 10.1016/j.peptides.2009.02.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2009] [Revised: 02/23/2009] [Accepted: 02/26/2009] [Indexed: 11/30/2022]
Abstract
Jingzhaotoxin-34 (JZTX-34) is a 35-residue polypeptide from the venom of Chinese tarantula Chilobrachys jingzhao. Our previous work reported its full-length cDNA sequence encoding a precursor with 87 residues. In this study we report the protein expression and biological function characterization. The toxin was efficiently expressed by the secretary pathway in yeast. Under whole-cell patch-clamp mode, the expressed JZTX-34 was able to inhibit tetrodotoxin-sensitive (TTX-S) sodium currents (IC(50) approximately 85 nM) while having no significant effects on tetrodotoxin-resistant (TTX-R) sodium currents on rat dorsal root ganglion neurons. The inhibition of TTX-S sodium channels was completely reversed by strong depolarization (+120 mV). Toxin treatment altered neither channel activation and inactivation kinetics nor recovery rate from inactivation. However, it is interesting to note that in contrast to huwentoxin-IV, a recently identified receptor site-4 toxin from Ornithoctonus huwena venom, 100 nM JZTX-34 caused a negative shift of steady-state inactivation curve of TTX-S sodium channels by approximately 10 mV. The results indicated that JZTX-34 might inhibit mammalian sensory neuronal sodium channels through a mechanism similar to HWTX-IV by trapping the IIS4 voltage sensor in the resting conformation, but their binding sites should not overlay completely.
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Affiliation(s)
- Jinjun Chen
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha, PR China
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Jiang L, Peng L, Zhang Y, Chen J, Zhang D, Liang S. Expression, purification and characterization of a group of lectin-like peptides from the spider Ornithoctonus huwena. Peptides 2009; 30:669-74. [PMID: 19150376 DOI: 10.1016/j.peptides.2008.12.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Revised: 11/30/2008] [Accepted: 12/02/2008] [Indexed: 10/21/2022]
Abstract
By sequencing random clones from the venom gland cDNA library of the spider Ornithoctonus huwena, a transcript, named SHL-Ib1, encoding a lectin-like peptide was cloned. The amino acid sequence of the putative mature peptide of SHL-Ib1 is identical, except for seven different residues, with that of SHL-I, a lectin found in the venom of O. huwena. The mature peptides of SHL-Ib1b and SHL-Ib1c are the mutants of SHL-Ib1 with two or three amino acid residues truncated at the C-terminal. The recombinant SHL-Ib1b and SHL-Ib1c were expressed successfully by the yeast expression system and purified by using a combination of ion-exchange and reverse phase high performance liquid chromatography (HPLC). The molecular masses of the two expressed peptides were identified by mass spectrometry, indicating that the C-terminals of the two peptides were not amidated. The two peptides can agglutinate human erythrocytes at minimal concentrations of 0.75 and 1.475mg/ml, respectively. Structure modeling of SHL-Ib1 has given a clue to the low agglutination bioactivities of these recombinant toxins. These lectin-like peptides, due to the small molecular sizes, may have the advantage to investigate the binding mechanism of the lectin and have the potential to be the carrier for drug delivery.
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Chen J, Zhao L, Jiang L, Meng E, Zhang Y, Xiong X, Liang S. Transcriptome analysis revealed novel possible venom components and cellular processes of the tarantula Chilobrachys jingzhao venom gland. Toxicon 2008; 52:794-806. [DOI: 10.1016/j.toxicon.2008.08.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Revised: 08/03/2008] [Accepted: 08/12/2008] [Indexed: 11/30/2022]
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Binford GJ, Bodner MR, Cordes MHJ, Baldwin KL, Rynerson MR, Burns SN, Zobel-Thropp PA. Molecular evolution, functional variation, and proposed nomenclature of the gene family that includes sphingomyelinase D in sicariid spider venoms. Mol Biol Evol 2008; 26:547-66. [PMID: 19042943 DOI: 10.1093/molbev/msn274] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The venom enzyme sphingomyelinase D (SMase D) in the spider family Sicariidae (brown or fiddleback spiders [Loxosceles] and six-eyed sand spiders [Sicarius]) causes dermonecrosis in mammals. SMase D is in a gene family with multiple venom-expressed members that vary in functional specificity. We analyze molecular evolution of this family and variation in SMase D activity among crude venoms using a data set that represents the phylogenetic breadth of Loxosceles and Sicarius. We isolated a total of 190 nonredundant nucleotide sequences encoding 168 nonredundant amino acid sequences of SMase D homologs from 21 species. Bayesian phylogenies support two major clades that we name alpha and beta, within which we define seven and three subclades, respectively. Sequences in the alpha clade are exclusively from New World Loxosceles and Loxosceles rufescens and include published genes for which expression products have SMase D and dermonecrotic activity. The beta clade includes paralogs from New World Loxosceles that have no, or reduced, SMase D and no dermonecrotic activity and also paralogs from Sicarius and African Loxosceles of unknown activity. Gene duplications are frequent, consistent with a birth-and-death model, and there is evidence of purifying selection with episodic positive directional selection. Despite having venom-expressed SMase D homologs, venoms from New World Sicarius have reduced, or no, detectable SMase D activity, and Loxosceles in the Southern African spinulosa group have low SMase D activity. Sequence conservation mapping shows >98% conservation of proposed catalytic residues of the active site and around a plug motif at the opposite end of the TIM barrel, but alpha and beta clades differ in conservation of key residues surrounding the apparent substrate binding pocket. Based on these combined results, we propose an inclusive nomenclature for the gene family, renaming it SicTox, and discuss emerging patterns of functional diversification.
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Affiliation(s)
- Greta J Binford
- Department of Biology, Lewis and Clark College, Portland, OR, USA.
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Discovery of a distinct superfamily of Kunitz-type toxin (KTT) from tarantulas. PLoS One 2008; 3:e3414. [PMID: 18923708 PMCID: PMC2561067 DOI: 10.1371/journal.pone.0003414] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2008] [Accepted: 09/16/2008] [Indexed: 12/02/2022] Open
Abstract
Background Kuntiz-type toxins (KTTs) have been found in the venom of animals such as snake, cone snail and sea anemone. The main ancestral function of Kunitz-type proteins was the inhibition of a diverse array of serine proteases, while toxic activities (such as ion-channel blocking) were developed under a variety of Darwinian selection pressures. How new functions were grafted onto an old protein scaffold and what effect Darwinian selection pressures had on KTT evolution remains a puzzle. Principal Findings Here we report the presence of a new superfamily of KTTs in spiders (Tarantulas: Ornithoctonus huwena and Ornithoctonus hainana), which share low sequence similarity to known KTTs and is clustered in a distinct clade in the phylogenetic tree of KTT evolution. The representative molecule of spider KTTs, HWTX-XI, purified from the venom of O. huwena, is a bi-functional protein which is a very potent trypsin inhibitor (about 30-fold more strong than BPTI) as well as a weak Kv1.1 potassium channel blocker. Structural analysis of HWTX-XI in 3-D by NMR together with comparative function analysis of 18 expressed mutants of this toxin revealed two separate sites, corresponding to these two activities, located on the two ends of the cone-shape molecule of HWTX-XI. Comparison of non-synonymous/synonymous mutation ratios (ω) for each site in spider and snake KTTs, as well as PBTI like body Kunitz proteins revealed high Darwinian selection pressure on the binding sites for Kv channels and serine proteases in snake, while only on the proteases in spider and none detected in body proteins, suggesting different rates and patterns of evolution among them. The results also revealed a series of key events in the history of spider KTT evolution, including the formation of a novel KTT family (named sub-Kuntiz-type toxins) derived from the ancestral native KTTs with the loss of the second disulfide bridge accompanied by several dramatic sequence modifications. Conclusions/Significance These finding illustrate that the two activity sites of Kunitz-type toxins are functionally and evolutionally independent and provide new insights into effects of Darwinian selection pressures on KTT evolution, and mechanisms by which new functions can be grafted onto old protein scaffolds.
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Wang M, Diao J, Li J, Tang J, Lin Y, Hu W, Zhang Y, Xiao Y, Liang S. JZTX-IV, a unique acidic sodium channel toxin isolated from the spider Chilobrachys jingzhao. Toxicon 2008; 52:871-80. [PMID: 18848955 DOI: 10.1016/j.toxicon.2008.08.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2008] [Revised: 08/27/2008] [Accepted: 08/29/2008] [Indexed: 11/27/2022]
Abstract
Neurotoxins are important tools to explore the structure and function relationship of different ion channels. From the venom of Chinese spider Chilobrachys jingzhao, a novel toxin, Jingzhaotoxin-IV (JZTX-IV), is isolated and characterized. It consists of 34 amino acid residues including six acidic residues clustered with negative charge (pI=4.29). The full-length cDNA of JZTX-IV encodes an 86-amino acid precursor containing a signal peptide of 21 residues, a mature peptide of 34 residues and an intervening sequence of 29 residues with terminal Lys-Gly as the signal of amidation. Under whole-cell patch clamp conditions, JZTX-IV inhibits current and slows the inactivation of sodium channels by shifting the voltage dependence of activation to more depolarized potentials on DRG neurons, therefore, differs from the classic site 4 toxins that shift voltage dependence of activation in the opposite direction. In addition, JZTX-IV shows a slowing inactivation of sodium channel with a hyperpolarizing shift of the steady-state inactivation on acutely isolated rat cardiac cell and DRG neurons, differs from the classic site 3 toxins that do not affect the steady-state of inactivation. At high concentration, JZTX-IV has no significant effect on tetrodotoxin-resistant (TTX-R) sodium channels on rat DRG neurons and tetrodotoxin-sensitive (TTX-S) sodium channels on hippocampal neurons. Our data establish that, contrary to known toxins, JZTX-IV neither binds to the previously characterized classic site 4, nor site 3 by modifying channel gating, thus making it a novel probe of channel gating in sodium channels with potential to shed new light on this process.
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Affiliation(s)
- Meichi Wang
- Key Laboratory of Protein Chemistry and Developmental Biology of the Ministry of Education, The College of Life Science, Hunan Normal University, Lushan Road, Yuelu District, Changsha, Hunan 410081, China
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19
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Molecular diversification based on analysis of expressed sequence tags from the venom glands of the Chinese bird spider Ornithoctonus huwena,. Toxicon 2008; 51:1479-89. [DOI: 10.1016/j.toxicon.2008.03.024] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2008] [Revised: 03/22/2008] [Accepted: 03/25/2008] [Indexed: 11/18/2022]
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20
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Xiao Y, Luo X, Kuang F, Deng M, Wang M, Zeng X, Liang S. Synthesis and characterization of huwentoxin-IV, a neurotoxin inhibiting central neuronal sodium channels. Toxicon 2007; 51:230-9. [PMID: 18054060 DOI: 10.1016/j.toxicon.2007.09.008] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2007] [Revised: 09/18/2007] [Accepted: 09/25/2007] [Indexed: 10/22/2022]
Abstract
Our previous work demonstrated that huwentoxin-IV was an inhibitor cystine knot peptide from Chinese tarantula Ornithoctonus huwena venom that blocked tetrodotoxin-sensitive voltage-gated sodium channels from mammalian sensory neurons [Peng, K., Shu, Q., Liu, Z., Liang, S., 2002. Function and solution structure of huwentoxin-IV, a potent neuronal tetrodotoxin (TTX)-sensitive sodium channel antagonist from Chinese bird spider Selenocosmia huwena. J. Biol. Chem. 277(49), 47564-47571]. However, the actions of the neurotoxin on central neuronal sodium channels remain unknown. In this study, we chemically synthesized native huwentoxin-IV and found that sodium channel isoforms from rat hippocampus neurons were also sensitive to native and synthetic toxins, but the toxin-binding affinity (IC(50) approximately 0.4 microM) was 12-fold lower than to peripheral isoforms. The blockade by huwentoxin-IV could be reversed by strong depolarization due to the dissociation of toxin-channel complex as observed for receptor site 3 toxins. Moreover, small unilamellar vesicle-binding assays showed that in contrast to ProTx-II from the tarantula Thrixopelma pruriens, huwentoxin-IV almost lacked the ability to partition into the negatively charged and neutral phospholipid bilayer of artificial membranes. These findings indicated that huwentoxin-IV was a sodium channel antagonist preferentially targeting peripheral isoforms via a mechanism quite different from ProTx-II.
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Affiliation(s)
- Yucheng Xiao
- Life Sciences College, Hunan Normal University, Changsha, Hunan 410081, PR China
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21
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Zeng X, Deng M, Lin Y, Yuan C, Pi J, Liang S. Isolation and characterization of Jingzhaotoxin-V, a novel neurotoxin from the venom of the spider Chilobrachys jingzhao. Toxicon 2007; 49:388-99. [PMID: 17157888 DOI: 10.1016/j.toxicon.2006.10.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2006] [Revised: 10/08/2006] [Accepted: 10/24/2006] [Indexed: 11/18/2022]
Abstract
Jingzhaotoxin-V (JZTX-V), a 29-residue polypeptide, is derived from the venom of the spider Chilobrachys jingzhao. Its cDNA determined by rapid amplification of 3' and 5'-cDNA ends encoded an 83-residue precursor with a pro-region of 16 residues. JZTX-V inhibits tetrodotoxin-resistant and tetrodotoxin-sensitive sodium currents in rat dorsal root ganglion neurons with IC50 values of 27.6 and 30.2 nM, respectively. Moreover, the toxin exhibits high affinity to the resting closed states of the channels. JZTX-V also inhibits Kv4.2 potassium currents expressed in Xenpus Laevis oocytes (IC50=604.2 nM), but has no effects on outward delay-rectified potassium channels expressed in Xenopus laevis oocytes. JZTX-V alters the gating properties of sodium channels by shifting the activation curves to the depolarizing direction and the inactivation curves to the hyperpolarizing direction. Small unilamellar vesicles binding assays show that the partitioning of JZTX-V into lipid bilayer requires negatively charged phospholipids. The phospholipid membrane binding activity of JZTX-V is also verified using intrinsic tryptophan fluorescence analysis as well as acrylamide-quenching assays. Importantly, human multiple sodium channel subtypes are attractive targets for treatment of pain, highlighting the importance of JZTX-V as potential lead for drug development.
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Affiliation(s)
- Xiongzhi Zeng
- The Key Laboratory of Protein Chemistry and Developmental Biology of Ministry of Education, College of Life Sciences, Hunan Normal University, Changsha 410081, China
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22
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Escoubas P. Molecular diversification in spider venoms: a web of combinatorial peptide libraries. Mol Divers 2006; 10:545-54. [PMID: 17096075 DOI: 10.1007/s11030-006-9050-4] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2004] [Accepted: 03/28/2006] [Indexed: 01/19/2023]
Abstract
Spider venoms are a rich source of novel pharmacologically and agrochemically interesting compounds that have received increased attention from pharmacologists and biochemists in recent years. The application of technologies derived from genomics and proteomics have led to the discovery of the enormous molecular diversity of those venoms, which consist mainly of peptides and proteins. The molecular diversity of spider peptides has been revealed by mass spectrometry and appears to be based on a limited set of structural scaffolds. Genetic analysis has led to a further understanding of the molecular evolution mechanisms presiding over the generation of these combinatorial peptide libraries. Gene duplication and focal hypermutation, which has been described in cone snails, appear to be common mechanisms to venomous mollusks and spiders. Post-translational modifications, fine structural variations and new molecular scaffolds are other potential mechanisms of toxin diversification, leading to the pharmacologically complex cocktails used for predation and defense.
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Affiliation(s)
- Pierre Escoubas
- Institut de Pharmacologie Moléculaire et Cellulaire (IPMC) CNRS UMR 6097, 660 Route des Lucioles, Valbonne, France.
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23
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Liu Z, Dai J, Dai L, Deng M, Hu Z, Hu W, Liang S. Function and Solution Structure of Huwentoxin-X, a Specific Blocker of N-type Calcium Channels, from the Chinese Bird Spider Ornithoctonus huwena. J Biol Chem 2006; 281:8628-35. [PMID: 16439354 DOI: 10.1074/jbc.m513542200] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Huwentoxin-X (HWTX-X) is a novel peptide toxin, purified from the venom of the spider Ornithoctonus huwena. It comprises 28 amino acid residues including six cysteine residues as disulfide bridges linked in the pattern of I-IV, II-V, and III-VI. Its cDNA, determined by rapid amplification of 3' and 5' cDNA ends, encodes a 65-residue prepropeptide. HWTX-X shares low sequence homology with omega-conotoxins GVIA and MVIIA, two well known blockers of N-type Ca2+ channels. Nevertheless, whole cell studies indicate that it can block N-type Ca2+ channels in rat dorsal root ganglion cells (IC50 40 nm) and the blockage by HWTX-X is completely reversible. The rank order of specificity for N-type Ca2+ channels is GVIA approximately HWTX-X > MVIIA. In contrast to GVIA and MVIIA, HWTX-X had no detectable effect on the twitch response of rat vas deferens to low frequency electrical stimulation, indicating that HWTX-X has different selectivity for isoforms of N-type Ca2+ channels, compared with GVIA or MVIIA. A comparison of the structures of HWTX-X and GVIA reveals that they not only adopt a common structural motif (inhibitor cystine knot), but also have a similar functional motif, a binding surface formed by the critical residue Tyr, and several basic residues. However, the dissimilarities of their binding surfaces provide some insights into their different selectivities for isoforms of N-type Ca2+ channels.
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MESH Headings
- Amino Acid Motifs
- Amino Acid Sequence
- Animals
- Calcium Channel Blockers/administration & dosage
- Calcium Channel Blockers/toxicity
- Cells, Cultured
- Cockroaches
- Conserved Sequence
- Dose-Response Relationship, Drug
- Female
- Ganglia, Spinal/cytology
- Ganglia, Spinal/drug effects
- Inhibitory Concentration 50
- Injections, Intraperitoneal
- Male
- Mice
- Mice, Inbred Strains
- Models, Molecular
- Molecular Sequence Data
- Neurons/drug effects
- Protein Folding
- Protein Structure, Secondary
- Rats
- Rats, Sprague-Dawley
- Sequence Homology, Amino Acid
- Solutions
- Spider Venoms/chemistry
- Spider Venoms/metabolism
- Spider Venoms/toxicity
- Spiders/chemistry
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Affiliation(s)
- Zhonghua Liu
- College of Life Sciences, Peking University, Beijing 100087, China
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Kozlov S, Grishin E. Classification of spider neurotoxins using structural motifs by primary structure features. Single residue distribution analysis and pattern analysis techniques. Toxicon 2005; 46:672-86. [PMID: 16169031 DOI: 10.1016/j.toxicon.2005.07.009] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2005] [Revised: 07/12/2005] [Accepted: 07/13/2005] [Indexed: 11/20/2022]
Abstract
In recent years the data on the novel structures of spider toxins have been greatly increasing. The sequence data should be classified. We introduced two primary structure analysis techniques-single residue distribution analysis (SRDA) and pattern analysis for classifying spider polypeptide toxins with molecular weight less than 10kDa. For multiple sequence alignment, we also introduced three novel sequence representation formats named as a simple record, motif record and a pattern record, which can be useful for large-scale analysis of structures. About 300 sequences of spider toxins were analyzed and nine primary structure motifs were identified. New classification of spider toxins was proposed on the basis of previously described principal structural motif (PSM) and extra structural motif (ESM) [Kozlov, S.A., Malyavka, A.A., McCutchen, B., Lu, A., Schepers, E., Herrmann, R., Grishin, E.V., 2005. A novel strategy for the identification of toxin-like structures in spider venom. Proteins 59 (1), 131-140]. Five main structural classes were revealed, and for putative ion channel inhibitors from the most numerous classes 1, 2, and 3, five-digital personal ID numbers were introduced. A reference table with simple, motif and pattern representation sequence formats was created for all analyzed structures.
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Affiliation(s)
- Sergey Kozlov
- Neuroreceptors and Neuroregulators Department, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya, 16/10, 117997 Moscow, Russian Federation.
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Ji W, Zhang X, Hu H, Chen J, Gao Y, Liang S, An C. Expression and purification of Huwentoxin-I in baculovirus system. Protein Expr Purif 2005; 41:454-8. [PMID: 15866735 DOI: 10.1016/j.pep.2005.02.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2005] [Revised: 02/16/2005] [Indexed: 11/21/2022]
Abstract
Huwentoxin-I (HWTX-I) is a novel neurotoxin isolated from the venom of Orinithoctonus huwena. Based on its biological activity, HWTX-I could be developed as a pain-killer for clinical purpose. Production of HWTX-I by the bacterium or yeast expression systems resulted in poor yields and the purified protein was proved to have lower biological activity than that of native one. So, for the first time, we introduced a new method to express HWTX-I gene in Sf9 cells using baculovirus expression system. Recombinant HWTX-I was recognized by Western blotting and then purified by nickel-chelating affinity chromatography under native conditions. Recombinant HWTX-I showed identical amino acid sequence as native form and exhibited similar effect on muscular transmission with that of native form. These results indicate that the baculovirus expression system and native purification strategy are viable ways to produce active HWTX-I.
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Affiliation(s)
- Wenjie Ji
- National Laboratory of Protein Engineering and Plant Genetic Engineering, College of Life Sciences, Peking University, Beijing 100871, People's Republic of China
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Xiao Y, Tang J, Hu W, Xie J, Maertens C, Tytgat J, Liang S. Jingzhaotoxin-I, a Novel Spider Neurotoxin Preferentially Inhibiting Cardiac Sodium Channel Inactivation. J Biol Chem 2005; 280:12069-76. [PMID: 15548530 DOI: 10.1074/jbc.m411651200] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Jingzhaotoxin-I (JZTX-I), a 33-residue polypeptide, is derived from the Chinese tarantula Chilobrachys jing-zhao venom based on its ability to evidently increase the strength and the rate of vertebrate heartbeats. The toxin has three disulfide bonds with the linkage of I-IV, II-V, and III-VI that is a typical pattern found in inhibitor cystine knot molecules. Its cDNA determined by rapid amplification of 3'- and 5'-cDNA ends encoded a 62-residue precursor with a small proregion of eight residues. Whole-cell configuration indicated that JZTX-I was a novel neurotoxin preferentially inhibiting cardiac sodium channel inactivation by binding to receptor site 3. Although JZTX-I also exhibits the interaction with channel isoforms expressing in mammalian and insect sensory neurons, its affinity for tetrodotoxin-resistant subtype in mammalian cardiac myocytes (IC50 = 31.6 nm) is approximately 30-fold higher than that for tetrodotoxin-sensitive subtypes in latter tissues. Not affecting outward delay-rectified potassium channels expressed in Xenopus laevis oocytes and tetrodotoxin-resistant sodium channels in mammal sensory neurons, JZTX-I hopefully represents a potent ligand to discriminate cardiac sodium channels from neuronal tetrodotoxin-resistant isoforms. Furthermore, different from any reported spider toxins, the toxin neither modifies the current-voltage relationships nor shifts the steady-state inactivation of sodium channels. Therefore, JZTX-I defines a new subclass of spider sodium channel toxins. JZTX-I is an alpha-like toxin first reported from spider venoms. The result provides an important witness for a convergent functional evolution between spider and other animal venoms.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Cells, Cultured
- Cloning, Molecular
- DNA, Complementary/metabolism
- Disulfides/chemistry
- Dose-Response Relationship, Drug
- Evolution, Molecular
- Female
- Inhibitory Concentration 50
- Insecta
- Ligands
- Male
- Membrane Potentials
- Molecular Sequence Data
- Myocardium/metabolism
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Neurons/drug effects
- Neurons/metabolism
- Neurotoxins/chemistry
- Oocytes/drug effects
- Oocytes/metabolism
- Peptides/chemistry
- Peptides/pharmacology
- Phylogeny
- Potassium Channels/chemistry
- Protein Isoforms
- Rats
- Rats, Sprague-Dawley
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Sodium Channel Blockers/pharmacology
- Sodium Channels/chemistry
- Sodium Channels/metabolism
- Spider Venoms/chemistry
- Spider Venoms/pharmacology
- Spiders
- Tetrodotoxin/chemistry
- Time Factors
- Xenopus laevis
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Affiliation(s)
- Yucheng Xiao
- College of Life Sciences, Hunan Normal University, Changsha 410081, China
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27
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Sollod BL, Wilson D, Zhaxybayeva O, Gogarten JP, Drinkwater R, King GF. Were arachnids the first to use combinatorial peptide libraries? Peptides 2005; 26:131-9. [PMID: 15626513 DOI: 10.1016/j.peptides.2004.07.016] [Citation(s) in RCA: 165] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2004] [Accepted: 07/19/2004] [Indexed: 11/22/2022]
Abstract
Spiders, scorpions, and cone snails are remarkable for the extent and diversity of gene-encoded peptide neurotoxins that are expressed in their venom glands. These toxins are produced in the form of structurally constrained combinatorial peptide libraries in which there is hypermutation of essentially all residues in the mature-toxin sequence with the exception of a handful of strictly conserved cysteines that direct the three-dimensional fold of the toxin. This gene-based combinatorial peptide library strategy appears to have been first implemented by arachnids almost 400 million years ago, long before cone snails evolved a similar mechanism for generating peptide diversity.
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Affiliation(s)
- Brianna L Sollod
- Department of Molecular, Microbial, and Structural Biology, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06032-3305, USA
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Liang S. An overview of peptide toxins from the venom of the Chinese bird spider Selenocosmia huwena Wang [=Ornithoctonus huwena (Wang)]. Toxicon 2004; 43:575-85. [PMID: 15066414 DOI: 10.1016/j.toxicon.2004.02.005] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The bird spider Selenocosmia huwena Wang [=Ornithoctonus huwena (Wang)] is one of the most venomous spiders in China. The venom of this spider contains a mixture of compounds with different types of biological activity. About 400 proteins and peptides from the venom can be separated and detected by 2D electrophoresis. Of these, 14 peptide toxins have been purified and characterized from the venom of this spider, with several peptide toxins exhibiting structural similarity but high functional diversity. Most of these huwentoxins (HWTX) contain 30-40 amino acids with three disulfide bonds and adopt an "inhibitor cystine-knot" (ICK) motif in their three dimensional structure, except for huwentoxin-II (HWTX-II) which adopts a novel scaffold different from the ICK motif. As a group, the toxins possess quite different biological activities including inhibition of voltage-gated calcium and sodium channels, insecticidal activity, lectin-like agglutination, and inhibition of trypsin. Eight cDNAs encoding seven toxins, HWTX-I, -II, -III, -IIIa, -IV -V, and, -VII and one lectin, S. huwena lectin-I (SHL-I), have been cloned and sequenced. Comparison of the cDNA sequences of the eight peptides from S. huwena indicates that they can be classified into two different superfamilies according to the "prepro" region of their cDNA sequences.
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Affiliation(s)
- Songping Liang
- College of Life Sciences, Hunan Normal University, Changsha 410081, China.
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29
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Xiao Y, Tang J, Yang Y, Wang M, Hu W, Xie J, Zeng X, Liang S. Jingzhaotoxin-III, a novel spider toxin inhibiting activation of voltage-gated sodium channel in rat cardiac myocytes. J Biol Chem 2004; 279:26220-6. [PMID: 15084603 DOI: 10.1074/jbc.m401387200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have isolated a cardiotoxin, denoted jingzhaotoxin-III (JZTX-III), from the venom of the Chinese spider Chilobrachys jingzhao. The toxin contains 36 residues stabilized by three intracellular disulfide bridges (I-IV, II-V, and III-VI), assigned by a chemical strategy of partial reduction and sequence analysis. Cloned and sequenced using 3'-rapid amplification of cDNA ends and 5'-rapid amplification of cDNA ends, the full-length cDNA encoded a 63-residue precursor of JZTX-III. Different from other spider peptides, it contains an uncommon endoproteolytic site (-X-Ser-) anterior to mature protein and the intervening regions of 5 residues, which is the smallest in spider toxin cDNAs identified to date. Under whole cell recording, JZTX-III showed no effects on voltage-gated sodium channels (VGSCs) or calcium channels in dorsal root ganglion neurons, whereas it significantly inhibited tetrodotoxin-resistant VGSCs with an IC(50) value of 0.38 microm in rat cardiac myocytes. Different from scorpion beta-toxins, it caused a 10-mV depolarizing shift in the channel activation threshold. The binding site for JZTX-III on VGSCs is further suggested to be site 4 with a simple competitive assay, which at 10 microm eliminated the slowing currents induced by Buthus martensi Karsch I (BMK-I, scorpion alpha-like toxin) completely. JZTX-III shows higher selectivity for VGSC isoforms than other spider toxins affecting VGSCs, and the toxin hopefully represents an important ligand for discriminating cardiac VGSC subtype.
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Affiliation(s)
- Yucheng Xiao
- College of Life Sciences, Hunan Normal University, Changsha, Hunan 410081, People's Republic of China
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