A cytotoxic peptide from a marine sponge exhibits ion channel activity through vectorial-insertion into the membrane

作者：Iwamoto Masayuki; Shimizu Hirofumi; Muramatsu Ikunobu; Oiki Shigetoshi^*

来源：FEBS Letters, 2010, 584(18): 3995-3999.

DOI：10.1016/j.febslet.2010.08.007

• Amphipathycity
• beta-Helix
• Single-channel current
• Rectification
• Vectorial-insertion

A cytotoxic peptide, polytheonamide B (pTB), from marine sponge was examined for cytotoxic spectrum and specific activity to mammalian cells was demonstrated. pTB is composed of alternative D- and L-amino acid residues throughout the 48-mer peptide. This suggests the formation of a beta-helix similar to gramicidin channels. Planar bilayer experiments revealed that pTB forms monovalent cation-selective channels, being compatible with the inner pore diameter of similar to 4 angstrom for a beta-helical structure. pTB penetrated vectorially into the membrane, formed a channel by means of a single molecule, and remained in the membrane. These functional properties may account for specific cytotoxic activity.

• 出版日期2010-9-24