CSTX-13, a highly synergistically acting two-chain neurotoxic enhancer in the venom of the spiderCupiennius salei(Ctenidae)

Abstract

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.

Spider venom: enhancement of venom efficacy mediated by different synergistic strategies in Cupiennius salei

“…(i) Bioassays were performed with 0.315·pmol CSTX-1 mg -1 fly alone and in combination with 0.035·pmol CSTX-13·mg -1 fly (non-toxic concentration) corresponding to their molar ratio in the crude venom (9:1) (repetition of Wullschleger et al, 2004).…”

“…The amount of venom injected varies depending on size, activity, defense behaviour and venom sensitivity of a prey item (Malli et al, 1999;Wigger et al, 2002;Wullschleger and Nentwig, 2002). This optimal venom dosage is continued on the biochemical level through positive interactions among various venom components (Kuhn-Nentwig et al, 1998;Wullschleger et al, 2004). In C. salei venom, proteins with molecular masses above 10·kDa have been identified.…”

“…To date, toxicological information and sequence data for the neurotoxins CSTX-1 and CSTX-9, and the neurotoxic twochain enhancer peptide CSTX-13 have been reported (KuhnNentwig et al, 2004;Wullschleger et al, 2004). Furthermore, antimicrobially and cytolytically acting cupiennins have been identified.…”

“…Only limited information is available about possible synergistic effects of low molecular mass substances with neurotoxins immediately after venom injection into a prey item (Chan et al, 1975;Inceoglu et al, 2003;Wullschleger et al, 2004). It was previously shown that histamine and taurine facilitate the neurotoxic activity of CSTX-1 from C. salei (Kuhn-Nentwig et al, 1998).…”

Cupiennin 1a exhibits a remarkably broad, non-stereospecific cytolytic activity on bacteria, protozoan parasites, insects, and human cancer cells

“…These a-helical peptides are highly cationic and exhibit strong cytolytic activities towards different prokaryotic cells and human erythrocytes (Kuhn-Nentwig et al 2002b). A dual role is proposed for cupiennins in that: (1) due to their cytolytic activity they synergistically enhance the activity of neurotoxins and other venom peptides Wullschleger et al 2004Wullschleger et al , 2005 and (2) they protect chelicerae and venom glands against microbial infections (Kuhn-Nentwig 2003). The best investigated cytolytic peptide, cupiennin 1a, is characterised by a helix-hinge-helix structure (Pukala et al 2007a), comparable to the structure of latarcin 2a (M-zodatoxin-Lt2a), a cytolytic peptide isolated from the venom of the central Asian spider Lachesana tarabaevi (Zodariidae) (Kozlov et al 2006).…”