spider toxin

{{Short description|Family of toxins produced by spiders}}

{{Pfam_box

| Symbol = Toxin_9

| Name = Spider toxin

| image = 1IVA.pdb.png

| width =

| caption = Solution structure of omega-agatoxin-Aa4a from Agelenopsis aperta.{{PDB|1IVA}}; {{cite journal |vauthors=Reily MD, Holub KE, Gray WR, Norris TM, Adams ME | title = Structure-activity relationships for P-type calcium channel-selective omega-agatoxins | journal = Nat. Struct. Biol. | volume = 1 | issue = 12 | pages = 853–6 |date=December 1994 | pmid = 7773772 | doi = 10.1038/nsb1294-853 | s2cid = 42176867 }}

| Pfam= PF02819

| Pfam_clan = CL0083

| InterPro= IPR004169

| SMART=

| Prosite =

| SCOP = 1oav

| TCDB =

| OPM family= 112

| OPM protein= 1agg

| PDB=

}}

{{Pfam_box

| Symbol = Atracotoxin

| Name = Delta Atracotoxin

| image =

| width =

| caption =

| Pfam= PF05353

| InterPro= IPR008017

| SMART=

| Prosite =

| SCOP = 1qdp

| TCDB =

| OPM family=

| OPM protein= 1vtx

| PDB=

}}

{{Pfam_box

| Symbol = Toxin_35

| Name = Spider toxin CSTX family

| image =

| width =

| caption =

| Pfam= PF10530

| InterPro= IPR011142

| SMART=

| PROSITE = PDOC60029

| SCOP =

| TCDB =

| OPM family=

| OPM protein=

| PDB=

}}

{{Pfam_box

| Symbol = Toxin_12

| Name = Spider potassium channel inhibitory toxin

| image =

| width =

| caption =

| Pfam= PF07740

| Pfam_clan = CL0083

| InterPro= IPR011696

| SMART=

| Prosite =

| SCOP = 1d1h

| TCDB =

| OPM family= 112

| OPM protein= 1qk6

| PDB=

}}

Spider toxins are a family of proteins produced by spiders which function as neurotoxins. The mechanism of many spider toxins is through blockage of calcium channels.

A remotely related group of atracotoxins operate by opening sodium channels. Delta atracotoxin from the venom of the Sydney funnel-web spider produces potentially fatal neurotoxic symptoms in primates by slowing the inactivation of voltage-gated sodium channels.{{cite journal |vauthors=Mackay JP, King GF, Fletcher JI, Chapman BE, Howden ME |title=The structure of versutoxin (delta-atracotoxin-Hv1) provides insights into the binding of site 3 neurotoxins to the voltage-gated sodium channel |journal=Structure |volume=5 |issue=11 |pages=1525–1535 |year=1997 |pmid=9384567 |doi=10.1016/S0969-2126(97)00301-8|doi-access=free }} The structure of atracotoxin comprises a core beta region containing a triple-stranded a thumb-like extension protruding from the beta region and a C-terminal helix. The beta region contains a cystine knot motif, a feature seen in other neurotoxic polypeptides and other spider toxins, of the CSTX family.

Spider potassium channel inhibitory toxins is another group of spider toxins. A representative of this group is hanatoxin, a 35 amino acid peptide toxin which was isolated from Chilean rose tarantula (Grammostola rosea, syn. G. spatulata) venom. It inhibits the drk1 voltage-gated potassium channel by altering the energetics of gating.{{cite journal |vauthors=Shimada I, Sato K, Takahashi H, Kim JI, Min HJ, Swartz KJ |title=Solution structure of hanatoxin1, a gating modifier of voltage-dependent K(+) channels: common surface features of gating modifier toxins |journal=J. Mol. Biol. |volume=297 |issue=3 |pages=771–780 |year=2000 |pmid=10731427 |doi=10.1006/jmbi.2000.3609}} See also Huwentoxin-1.{{InterPro|IPR013140}}