Solution structure of an Old World-like neurotoxin from the venom of the New World scorpion Centruroides sculpturatus Ewing

Jablonsky, Michael J.; Watt, Dean D.; Krishna, N. Rama

doi:10.1016/s0022-2836(95)80062-x

Cited by 41 publications

(41 citation statements)

References 21 publications

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“…In this motif, two cysteine residues, located one turn apart in the a-helix, form two disulfide bridges with two cysteine residues separated by a single amino acid in the last strand of the b-sheet. The protein super-family containing such a CSab motif also includes some scorpion neurotoxins (Bontems et al 1991;Kobayashi et al 1991;Polikarpov et al 1999;Jablonsky et al 2001) and the plant protein brazzein, known for its intrinsic sweet taste (Caldwell et al 1998).…”

Section: Structure Of Defensinsmentioning

confidence: 99%

Plant defensins

Thomma

Cammue

Thevissen

2002

Planta

686

614

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Plant defensins are small, basic peptides that have a characteristic three-dimensional folding pattern that is stabilized by eight disulfide-linked cysteines. They are termed plant defensins because they are structurally related to defensins found in other types of organism, including humans. To date, sequences of more than 80 different plant defensin genes from different plant species are available. In Arabidopsis thaliana, at least 13 putative plant defensin genes (PDF) are present, encoding 11 different plant defensins. Two additional genes appear to encode plant defensin fusions. Plant defensins inhibit the growth of a broad range of fungi but seem nontoxic to either mammalian or plant cells. Antifungal activity of defensins appears to require specific binding to membrane targets. This review focuses on the classification of plant defensins in general and in Arabidopsis specifically, and on the mode of action of plant defensins against fungal pathogens.

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Section: Structure Of Defensinsmentioning

confidence: 99%

Plant defensins

Thomma

Cammue

Thevissen

2002

Planta

686

614

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“…A scorpion toxin with high affinity to VGSCs was isolated as well from the venom of Brazilian scorpion Tityus serrulatus and named Tityus γ toxin (TiTxγ) ). The three dimensional structure of several scorpion β-toxins has been resolved recently by NMR (Jablonsky et al 1999;Pintar et al 1999).…”

Section: Pharmacology Of the Vgscs: Binding Sites And Ligandsmentioning

confidence: 99%

Structure, function and pharmacology of voltage-gated sodium channels

Denac¹,

Mevissen²,

Scholtysik³

2000

Naunyn-Schmiedeberg's Archives of Pharmacology

141

108

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Voltage-gated sodium channels (VGSCs) are responsible for the initial inwards current during the depolarisation phase of action potential in excitable cells. Therefore, VGSCs are crucial for cardiac and nerve function, since the action potential of nerves and muscle cannot occur without them. Their importance in generation and transmission of signals has been known for more than 40 years but the more recent introduction of new electrophysiological methods and application of molecular biology techniques has led to an explosion of research on many different ion channels, including VGSCs. Their extraordinary biological importance makes them logical and obvious targets for toxins produced by animals and plants for attack or defence. The action of these and similar substances modulating the function of the VGSCs is interesting with respect to their possible use in medicine or use as tools in the study of these molecules. This review summarises recent progress in this research field and, in particular, considers what is known about the relationship of the structure to function, including a current understanding of the pharmacological modulation of VGSCs.

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“…Thus, the sequence I-S-S-G (19)(20)(21)(22) found in BotXIV is replaced by D-A-Y in LqhaIT. Finally, the third variable segment corresponds to residues 38-43, and includes three amino acids of the second LqhaIT b strand (34)(35)(36)(37)(38)(39) and the following b turn. Here also, BotXIV and a-insect toxins display totally different sequences: GHKSGH(38-43) vs. QWAGKY in LqhaIT for instance.…”

Section: Identification Of Divergent Regionsmentioning

confidence: 99%

A chimeric scorpion α‐toxin displays de novo electrophysiological properties similar to those of α‐like toxins

Bouhaouala‐Zahar

Benkhalifa

Srairi

et al. 2002

European Journal of Biochemistry

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BotXIV and LqhaIT are two structurally related long chain scorpion a-toxins that inhibit sodium current inactivation in excitable cells. However, while LqhaIT from Leiurus quinquestriatus hebraeus is classified as a true and strong insect a-toxin, BotXIV from Buthus occitanus tunetanus is characterized by moderate biological activities. To assess the possibility that structural differences between these two molecules could reflect the localization of particular functional topographies, we compared their sequences. Three structurally deviating segments located in three distinct and exposed loops were identified. They correspond to residues 8-10, 19-22, and 38-43. To evaluate their functional role, three BotXIV/LqhaIT chimeras were designed by transferring the corresponding LqhaIT sequences into BotXIV.Structural and antigenic characterizations of the resulting recombinant chimera show that BotXIV can accommodate the imposed modifications, confirming the structural flexibility of that particular a/b fold. Interestingly, substitution of residues 8-10 yields to a new electrophysiological profile of the corresponding variant, partially comparable to that one of a-like scorpion toxins. Taken together, these results suggest that even limited structural deviations can reflect functional diversity, and also that the structure-function relationships between insect a-toxins and a-like scorpion toxins are probably more complex than expected.

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Solution structure of an Old World-like neurotoxin from the venom of the New World scorpion Centruroides sculpturatus Ewing

Cited by 41 publications

References 21 publications

Plant defensins

Plant defensins

Structure, function and pharmacology of voltage-gated sodium channels

A chimeric scorpion α‐toxin displays de novo electrophysiological properties similar to those of α‐like toxins

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