48, Sh 21.61, Bg 19.94, Bg 20.19, Bg 20.79 and Bg 21.57 may check details be new members of the unclassified group of sea anemone toxins previously discovered [85]. Nevertheless, given that the targets on which these toxins exert their effect are still unknown, smaller or larger peptides more represented in some of these fractions might also account for the observed atypical paralyzing effect. Lastly, toxic fractions Bg 19.68 and Bg 19.25, predominantly composed of 2.6 and 4.8 kDa peptides, provoked a mutilating effect followed

by death of crabs. A more exhaustive analysis will reveal whether the peptide toxins implicated in this atypical effect belong to a new class of sea anemone peptides. Applications of peptidomic/peptidomic and transcriptomic to sea anemone venom studies are just starting, whereas other animal venoms have been more extensively explored. In the present work, the neurotoxic

fractions of the sea anemones B. granulifera and S. helianthus were PS-341 molecular weight fingerprinted in terms of molecular masses and hydrophobicity. Our study predicted a higher number of peptides than any other study of sea anemones. Moreover we found that type 1 sodium channel toxins and APETx-like peptides constitute the most distinguishable feature of so far studied sea anemone species belonging to Bunodosoma, as they are the most abundant and hydrophobic peptides in the neurotoxic fractions of these sea anemones. We found a variety of crab-paralyzing peptides in both sea anemones; although none of them was sequenced, we expect

that the smallest ones (<2000 Da) constitute a new family of toxic peptides, given that no crab-paralyzing peptide toxin of such small size has been previously Sitaxentan reported. This study was mainly supported by the project CNPq-CITMA 490194/2007-9 (Brazil), a post-doctoral fellowship to AJZ (FAPESP – 07/56525-3), FAPEMIG, INCTTOX, CAPES and CNPq (AMCP and MEL) and the grants from the Science and Technology Development Fund of Macau SAR (Ref. No. 058/2009) and Research Committee, University of Macau (Ref. No. UL017/09-Y1). We are very grateful to divers José Ramón García and José Ramón Guerra (Cebimar, Cuba) for collecting the sea anemone specimens, Maylin Díaz and Estrella Cuquerella (Cebimar, Cuba) for their assistance in the extraction of sea anemone secretion, Dr. Karla K. Florenço Ferraz (UFMG, Brazil) and Dr. Daniel Moreira dos Santos (UFMG, Brazil) for the molecular masses measurements. A.A. Rodriguez specially thanks Dr. Peter Højrup (Lighthouse data, Denmark) for a copy of the software GPMAW 9.0, and the financial support of the International Foundation for Science (travel grant and research grants F/4082-1, F/4082-2) and the Third World Academy of Sciences (Fellowship for research and advanced training application, and Research grant 06344-2007).