No abstract

Sea anemone venom contains a complex and diverse arsenal of peptides and proteins of pharmacological and biotechnological interest, however, only venom from a few species has been explored from a global perspective to date. In the present study, we identified the polypeptides present in the venom of the sea anemone Anthopleura dowii Verrill, 1869 through a transcriptomic and proteomic analysis of the tentacles and the proteomic profile of the secreted mucus. In our transcriptomic results, we identified 261 polypeptides related to or predicted to be secreted in the venom, including proteases, neurotoxins that could act as either potassium (K+) or sodium (Na+) channels inhibitors, protease inhibitors, phospholipases A2, and other polypeptides. Our proteomic data allowed the identification of 156 polypeptides—48 exclusively identified in the mucus, 20 in the tentacles, and 88 in both protein samples. Only 23 polypeptides identified by tandem mass spectrometry (MS/MS) were related to the venom and 21 exclusively identified in the mucus, most corresponding to neurotoxins and hydrolases. Our data contribute to the knowledge of evolutionary and venomic analyses of cnidarians, particularly of sea anemones.

The antibiotic activity of organic extracts from cultures of six species of phytoplankton, Synechococcus elongatus, Synechocystis sp., Amphiprora paludosa, Porphyridium cruentum, Chaetoceros muelleri and Dunaliella tertiolecta was examined. The bacteria used were Gram(-) strains, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae, and the Gram(+) strains were Bacillus subtilis, Staphylococcus aureus, and Microccocus luteus. All extracts inhibited the growth of B. subtilis and effected the generation of inhibition halos, ranging in diameter from 7.06 to 15.23 mm, for several bacteria species. Wide-spectrum antibacterial activity was observed in extracts from S. elongatus, Synechocystis sp., A. paludosa, P. cruentum, and C. muelleri. Thus, this five phytoplankton species can be used to control bacteria.

No abstract

Toxins that are secreted by cone snails are small peptides that are used to treat several diseases. However, their effects on parasites with human and veterinary significance are unknown. Toxoplasma gondii is an opportunistic parasite that affects approximately 30% of the world’s population and can be lethal in immunologically compromised individuals. The conventional treatment for this parasitic infection has remained the same since the 1950s, and its efficacy is limited to the acute phase of infection. These findings have necessitated the search for new drugs that specifically target T. gondii. We examined the effects of the synthetic toxin cal14.1a (s-cal14.1a) from C. californicus on the tachyzoite form of T. gondii. Our results indicate that, at micromolar concentrations, s-cal14.1a lowers viability and inhibits host cell invasion (by 50% and 61%, respectively) on exposure to extracellular parasites. Further, intracellular replication decreased significantly while viability of the host cell was unaffected. Our study is the first report on the antiparasitic activity of a synthetic toxin of C. californicus.