s-Box Jellyfish Pentapeptide-1 SP is a single chain peptide containing 5 amino acids. It is synthetically produced based on a sequence from Toxin CfTX-2, which is found in the box jellyfish, Chironex fleckeri.. The parent protein contains a maximum of 462 amino acids which may contain disulfide bonds and/or glycosylation, and consists of the proper sequence of the 20 standard amino acids.