The Caribbean Sea anemone Stichodactyla helianthus produces two pore-forming proteins, sticholysins I and II (StI and StII). To clarify the contribution of the fi rst thirty (StII) or thirty-one (StI) N-terminal amino acid residues to the activity of the toxins, four peptides spanning residues 1-31 of StI (StI1-31, StI12-31) and 1-30 of StII (StII1-30, StII11-30) were synthesized. StII1-30 was ...

Sea anemone cytolysins constitute a novel class of toxins that functions by forming channels in cell membranes. In contrast to the bacterial pore-forming toxins, there is little detailed information on the mechanism of action of these toxins and as yet no 3-D structures have been determined. These highly basic toxins of mass ∼20 kDa generate pores in membranes containing sphingomyelin by formin...

The major protease inhibitor from the sea anemone Stichodactyla helianthus (ShPI-1) is a non-specific inhibitor that binds trypsin and other trypsin-like enzymes, as well as chymotrypsin, and human neutrophil elastase. We performed site-directed mutagenesis of ShPI-1 to produce two variants (rShPI-1/K13L and rShPI/Y15S) that were expressed in Pichia pastoris, purified, and characterized. After ...

Through a combination of fluorescence microscopy and patch-clamp analysis we have identified a striking alteration in K(+) channel expression in terminally differentiated human CCR7(-)CD45RA(-) effector memory T lymphocytes (T(EM)). Following activation, T(EM) cells expressed significantly higher levels of the voltage-gated K(+) channel Kv1.3 and lower levels of the calcium-activated K(+) chann...

We studied the influence of lipid composition on the immunomodulatory capacity of liposomal vesicles. Liposomes composed of different phosphatidylcholines (PC) and cholesterol were assayed as adjuvants for rhEGF conjugated or not to P64k from Neisseria meningitidis, and dipalmitoylphosphatidylcholine (DPPC) liposomes with or without cholesterol were tested for the encapsulation of allergens (ma...

A high resolution structure in solution has been determined for the polypeptide neurotoxin I, from the sea anemone Stichodactyla helianthus, using NMR data, distance geometry calculations, and refinement by back-calculation of two-dimensional nuclear Overhauser enhancement (NOE) spectra. A set of 913 distance constraints derived from NOEs was used, together with a large set of lower distance bo...

Potent cytolytic activity was exhibited by proteins extracted from three sea anemones viz. Heteractis magnifica, Stichodactyla haddoni and Paracodylactis sinensis by affecting the red blood corpuscles (RBC) and the mouse fibroblast cell line (L929) and leukemia cell line (P388). Crude toxin of all the three anemone species induced spontaneous hemolysis of chicken, goat and human erythrocytes. T...

BACKGROUND Since the first report of a dog that developed severe systemic symptoms in response to a second injection of sea anemone toxin by Richet and Portier in 1902, no clear human cases of anaphylaxis related to exposure to sea anemones has been reported in the literature. METHODS A 24-year-old man with an episode of local urticaria on his first contact with a sea anemone (Stichodactyla h...