CSTX-13, a highly synergistically acting two-chain neurotoxic enhancer in the venom of the spider Cupiennius salei (Ctenidae).
The survival of the spider Cupiennius salei depends on its hunting success, which largely relies on its immediately paralyzing multicomponent venom. Here, we report on the isolation and characterization of CSTX-13, a neurotoxic enhancer in the spider venom. De novo elucidation of the disulfide bridge pattern of CSTX-13 and the neurotoxin CSTX-1 by tandem MS revealed an identical arrangement. However, in contrast to CSTX-1, CSTX-13 is a two-chain peptide with two interchain and two intrachain disulfide bridges. Furthermore, the insecticidal activity of CSTX-13 is synergistically increased in the presence of K+ ions as well as of the cytolytic peptide cupiennin 1a. We demonstrated that the weakly neurotoxic CSTX-13 enhances the paralytic activity of the neurotoxin CSTX-1 by 65% when it is administered with the latter at its entirely nontoxic physiological concentration, which is 440 times below its LD50 concentration.
Zoological Institute, University of Bern, Baltzerstrasse 6, CH-3012 Bern, Switzerland.
Benno
B
Wullschleger
Lucia
L
Kuhn-Nentwig
Jan
J
Tromp
Urs
U
Kämpfer
Johann
J
Schaller
Stefan
S
Schürch
Wolfgang
W
Nentwig
D000595:Amino Acid Sequence; D000818:Animals; D004331:Drosophila melanogaster / Q000187:drug effects; D004357:Drug Synergism; D008969:Molecular Sequence Data; D013111:Spider Venoms / Q000737:chemistry* / Q000302:isolation & purification / Q000633:toxicity*; D013112:Spiders / Q000737:chemistry*
C439583:CSTX-9, Cupiennius salei; D013111:Spider Venoms