Venomic analyses of Scolopendra viridicornis nigra and Scolopendra angulata (Centipede, Scolopendromorpha): shedding light on venoms from a neglected group.

Centipedes are venomous arthropods responsible for a significant number of non-lethal human envenomations. Despite this, information about the composition and function of their venom contents is scarce. In this study, we have used a 'structure to function' proteomic approach combining two-dimensional chromatography (2D-LC), electrospray ionization quadrupole/time-of-flight mass spectrometry (ESI-Q-TOF/MS), N-terminal sequencing and similarity searching to better understand the complexities of the venoms from two Brazilian centipede species: Scolopendra viridicornis nigra and Scolopendra angulata. Comparisons between the LC profiles and the mass compositions of the venoms of the two species are provided. The observed molecular masses ranged from 3019.62 to 20996.94Da in S. viridicornis nigra (total: 62 molecular masses) and from 1304.73 to 22639.15Da in S. angulata (total: 65 molecular masses). Also, the N-termini of representatives of 10 protein/peptide families were successfully sequenced where nine of them showed no significant similarity to other protein sequences deposited in the Swiss-Prot database. A screening for insecto-toxic activities in fractions from S. viridicornis venom has also been performed. Six out of the 12 tested fractions were responsible for clear toxic effects in house flies. This work demonstrates that centipede venoms might be a neglected but important source of new bioactive compounds.