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.q 2004 Elsevier Ltd. All rights reserved.

Recently, it was found that in the gynogenetic haploid and diploid embryos of goldfish, which have exactly the same genome, the haploid condition results in obstruction of gene expression and abnormal development while the diploid embryos have normal gene expression and development. A diploid-dependent regulatory apparatus was proposed to regulate gene expression. To study the difference at the protein expression level of the embryos of haploid and diploid in development, we extracted the total proteins of both the gynogenetic haploid and diploid embryos of goldfish in the same eye formation stage. Two-dimensional polyacrylamide gel electrophoresis was used to separate proteins. The stained gel images were analyzed with the PDQUEST software.A part of protein spots that were differentially expressed in haploid and diploid embryos were identified by matrix assisted laser desorption/ionisation-time of flightmass spectrometry and database analysis. Sixteen protein spots that were absolutely different (only expressed in diploid embryos but not in haploid embryos or vice versa)and 16 protein spots that were up- and downregulated were identified unambiguously,which include some proteins that are correlative with eyes development, nerve development,developing regulation, cell differentiation, and signal transduction. The different significantly gene expression during embryos developing between diploid and haploid is demonstrated.

two toxins exhibits sequence identity with other spider toxins such as ProTx-I (64%), SGTx (57%), SNX-482 (55%), and Hanatoxin (54%). HWTX-V can reversibly paralyze locusts and cockroaches for several hours with a ED50 value as 16±5mg/g to locusts, and a larger dose of the toxin can cause death. However, mHWTX-V shows no significant effect on locusts and cockroaches. The structure–activity relationship indicates that the residues Phe34 and Ser35 in the C-terminus of HWTX-V are the key residues of the biological activity.c 2003 Elsevier Science Ltd. All rights reserved.

A neurotoxic peptide, named Hainantoxin-V (HNTX-V), was isolated from the venom of the Chinese bird spider Selenocosmia hainana. The complete amino acid sequence of HNTX-V has been determined by Edman degradation and found to contain 35 amino acid residues with three disulfide bonds. Under whole-cell patch-clamp mode, HNTX-V was proved to inhibit the tetrodotoxin-sensitive (TTX-S) sodium currents while it had no any effects on tetrodotoxin-resistant (TTX-R) sodium currents on adult rat dorsal root ganglion neurons. The inhibition of TTX-S sodium currents by HNTX-V was tested to be concentrate-dependent with the IC50 value of 42.3nM. It did not affect the activation and inactivation kinetics of currents and did not have the effect on the active threshold of sodium channels and the voltage of peak inward currents. However,100nM HNTX-V caused a 7.7mV hyperpolarizing shift in the voltage midpoint of steady-state sodium channel inactivation.The results indicated that HNTX-V inhibited mammalian voltage-gated sodium channels through a novel mechanism distinct from other spider toxins such as d-ACTXs, m-agatoxins I-VI which bind to receptor site three to slow the inactivation kinetics of sodium currents.

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 IC50 value of0.38M in rat cardiac myocytes.Different from scorpion -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 10M eliminated the slowing currents induced by Buthus martensi Karsch I (BMK-I, scorpion-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.