AsKC11, a Kunitz Peptide from , Is a Novel Activator of G Protein-Coupled Inward-Rectifier Potassium Channels.

(1) Background: G protein-coupled inward-rectifier potassium (GIRK) channels, especially neuronal GIRK1/2 channels, have been the focus of intense research interest for developing drugs against brain diseases. In this context, venom peptides that selectively activate GIRK channels can be seen as a new source for drug development. Here, we report on the identification and electrophysiological characterization of a novel activator of GIRK1/2 channels, AsKC11, found in the venom of the sea anemone .

Interactions of Sea Anemone Toxins with Insect Sodium Channel-Insights from Electrophysiology and Molecular Docking Studies.

Animal venoms are considered as a promising source of new drugs. Sea anemones release polypeptides that affect electrical activity of neurons of their prey. Voltage dependent sodium (Nav) channels are the common targets of Av1, Av2, and Av3 toxins from and CgNa from .

APETx4, a Novel Sea Anemone Toxin and a Modulator of the Cancer-Relevant Potassium Channel K10.1.

The human ether-à-go-go channel (hEag1 or K10.1) is a cancer-relevant voltage-gated potassium channel that is overexpressed in a majority of human tumors. Peptides that are able to selectively inhibit this channel can be lead compounds in the search for new anticancer drugs.

Head and neck cancer cells and xenografts are very sensitive to palytoxin: decrease of c-jun n-terminale kinase-3 expression enhances palytoxin toxicity.

Objectives: Palytoxin (PTX), a marine toxin isolated from the Cnidaria (zooanthid) Palythoa caribaeorum is one of the most potent non-protein substances known. It is a very complex molecule that presents both lipophilic and hydrophilic areas. The effect of PTX was investigated in a series of experiments conducted in head and neck squamous cell carcinoma (HNSCC) cell lines and xenografts.

A natural point mutation changes both target selectivity and mechanism of action of sea anemone toxins.

APETx3, a novel peptide isolated from the sea anemone Anthopleura elegantissima, is a naturally occurring mutant from APETx1, only differing by a Thr to Pro substitution at position 3. APETx1 is believed to be a selective modulator of human ether-á-go-go related gene (hERG) potassium channels with a K(d) of 34 nM. In this study, APETx1, 2, and 3 have been subjected to an electrophysiological screening on a wide range of 24 ion channels expressed in Xenopus laevis oocytes: 10 cloned voltage-gated sodium channels (Na(V) 1.

Combining multidimensional liquid chromatography and MALDI-TOF-MS for the fingerprint analysis of secreted peptides from the unexplored sea anemone species Phymanthus crucifer.

Sea anemones are sources of biologically active proteins and peptides. However, up to date few peptidomic studies of these organisms are known; therefore most species and their peptide diversity remain unexplored. Contrasting to previous venom peptidomic works on sea anemones and other venomous animals, in the present study we combined pH gradient ion-exchange chromatography with gel filtration and reversed-phase chromatography, allowing the separation of the 1-10 kDa polypeptides from the secretion of the unexplored sea anemone Phymanthus crucifer (Cnidaria/Phymanthidae).

A bifunctional sea anemone peptide with Kunitz type protease and potassium channel inhibiting properties.

Sea anemone venom is a known source of interesting bioactive compounds, including peptide toxins which are invaluable tools for studying structure and function of voltage-gated potassium channels. APEKTx1 is a novel peptide isolated from the sea anemone Anthopleura elegantissima, containing 63 amino acids cross-linked by 3 disulfide bridges. Sequence alignment reveals that APEKTx1 is a new member of the type 2 sea anemone peptides targeting voltage-gated potassium channels (K(V)s), which also include the kalicludines from Anemonia sulcata.

Phyla- and Subtype-Selectivity of CgNa, a Na Channel Toxin from the Venom of the Giant Caribbean Sea Anemone Condylactis Gigantea.

Because of their prominent role in electro-excitability, voltage-gated sodium (Na(V)) channels have become the foremost important target of animal toxins. These toxins have developed the ability to discriminate between closely related Na(V) subtypes, making them powerful tools to study Na(V) channel function and structure. CgNa is a 47-amino acid residue type I toxin isolated from the venom of the Giant Caribbean Sea Anemone Condylactis gigantea.

CgNa, a type I toxin from the giant Caribbean sea anemone Condylactis gigantea shows structural similarities to both type I and II toxins, as well as distinctive structural and functional properties(1).

CgNa (Condylactis gigantea neurotoxin) is a 47-amino-acid- residue toxin from the giant Caribbean sea anemone Condylactis gigantea. The structure of CgNa, which was solved by 1H-NMR spectroscopy, is somewhat atypical and displays significant homology with both type I and II anemone toxins. CgNa also displays a considerable number of exceptions to the canonical structural elements that are thought to be essential for the activity of this group of toxins.

A new toxin from the sea anemone Condylactis gigantea with effect on sodium channel inactivation.

A new peptide toxin exhibiting a molecular weight of 5043Da (av.) and comprising 47 amino acid residues was isolated from the sea anemone Condylactis gigantea. Purification of the peptide was achieved by a multistep chromatographic procedure monitoring its strong paralytic activity on crustacea (LD(50) approx.

APETx1, a new toxin from the sea anemone Anthopleura elegantissima, blocks voltage-gated human ether-a-go-go-related gene potassium channels.

A new peptide, APETx1, which specifically inhibits human ether-a-go-go-related gene (HERG) channels, was purified from venom of the sea anemone Anthopleura elegantissima. APETx1 is a 42-amino acid peptide cross-linked by three disulfide bridges and shares 54% homology with BDS-I, another sea anemone K+ channel inhibitor. Although they differ in their specific targets, circular dichroism spectra and molecular modeling indicate that APETx1 and BDS-I have a common molecular scaffold and belong to the same structural family of K+ channel blocking peptides.