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The role of anthopleurin B (ApB) residues Asn-16, Thr-17 and Ser-19 to toxin affinity and isoform selectivity is determined. The results show that residues within and proximal to the C terminus of the Arg-14 loop are important modulators of ApB affinity for voltage-sensitive sodium channels (Na(sub v)'s), indicating that the loop and channel site 3 are likely in close contact.

Results show the periplasmic ankyrin-like protein AnkB exhibit four 33-amino-acid ankyrin repeats in a 183 amino acids stretch of the protein. Data further indicate that AnkB together with a hydrogen peroxide-inducible KatB protein forms a protective lattice work for hydrogen peroxide detoxification.

A study was conducted on the structure and function of Cerebratulus lacteus neurotoxin B-IV, specifically a tryptophan residue at position 30. The results show that substitution of Trp-30 with a serine causes a more than 40-fold reduction in specific toxicity while substitution by tyrosine and phenylalanine is well tolerated. Moreover, the findings indicate the importance of an aromatic residue at position 30 in toxin B-IV activity.

Mutants for anthopleurin A (ApA) and B (ApB) were generated to study the effect of substitutions at certain residues on the functional properties of the toxins' voltage-dependent sodium channels. Biochemical and molecular methods revealed that changes in the amino acid composition of recombinant Anthopleura toxins affected channel isoform selectivity and caused a shift in the orientation of cationic residues.

The polypeptide toxin anthopleurin B (ApB) from the sea anemone Anthopleura xanthogrammica was examined for the role of the anionic residues in the delayed activation of sodium channels that leads to positive inotropic effect on the human heart. Mutant toxins that carry a defective Lys-37 or His-39 have been found to have altered activities in intramolecular salt bridge formation. Further analysis of data from NMR studies suggest that the Lys-37 site may play a big role in the toxin's ability to act as a human heart stimulant.

The amino acid residues at positions 12 and 49 of the protein anthopleurin are important for differentiating the isoforms, and arginine at position 12 is involved in the high affinity of anthopleurin B (ApB) to neuronal Na channels. Many variable forms of anthopleurin are found in the venom of the sea anemone 'Anthopleura xanthogrammica', each of which is selective in its action. ApB modifies cardiac and neuronal channels while ApA prefers the cardiac channel. The differences in their affinity can help in the preparation of better cardiatonic drugs that affect cardiac Na channels.

The inherent mobility of the Arg14 loop is necessary for the toxins' ability to maintain a high-affinity channel complex throughout the continual conformational transitions experienced by the channel during its functional cycle is proposed.

The article explains the relation of hibernating myocardium to the downregulation of many mitochondrial proteins and upregulation of stress proteins. It was noted that the proteomic phenotype of hibernating myocardium has similarities to global changes in energy substrate metabolism and function in the advanced failing heart. And these proteomic changes may limit oxidative injury and impact functional recovery after revascularization.