Centipede (Scolopendra subspinipes mutilans) venom toxin peptide exhibits cytotoxic and cell growth effects in a concentration-dependent manner

Abstract

Centipede venom contains a variety of proteins, peptides, and enzymes. However, the biological actions of toxin peptides in centipede venom remain largely unknown. In this study, we identified a centipede (Scolopendra subspinipes mutilans) venom toxin peptide (SsmTP) that was shown to act as a cell growth factor at low concentrations-in vitro. SsmTP was found to consist of 66 amino acids that display seven cysteine residues, which exhibited high similarity to the predicted neurotoxin. SsmTP was expressed in the venom gland of S. s. mutilans. A recombinant SsmTP peptide of approximately 5.2 kDa was produced in baculovirus-infected insect cells. Interestingly, SsmTP exhibited cytotoxicity in murine cells in a concentration-dependent manner but displayed a cell growth effect at low concentrations. SsmTP at a low concentration also protected murine cells against oxidative damage through the inhibition of caspase-1 and apoptosis. Our data indicate that SsmTP acts as a cell growth factor and a toxin peptide in a concentration-dependent manner. Consequently, our results provide evidence that the identification of SsmTP, a centipede toxin peptide, may not only elucidate the biological action of toxin peptides but also offer additional insight into the pharmacological applications of centipede venoms.