title: Clavaspirin, an antibacterial and haemolytic peptide from Styela clava.
abstract: We cloned the precursor of a novel peptide from a cDNA library prepared from pharyngeal tissues of the tunicate, Styela clava. Its sequence predicted a histidine-rich, amidated 23-residue peptide (FLRF(IG)SVIHGIGHLVHHIGVAL-NH2) that we named clavaspirin. A synthetic clavaspirin was prepared and it was found that it killed Gram-positive and Gram-negative bacteria, permeabilized the outer and inner membranes of Escherichia coli, lysed phosphatidylglycerol (POPG) liposomes, and was potently haemolytic towards human and bovine erythrocytes. Each of these activities was performed more effectively at an acidic pH. Circular dichroism measurements of synthetic clavaspirin revealed a largely alpha-helical structure and polarized and residue-specific FTIR spectrometry showed that its association with phospholipid membranes was influenced by pH. Peptides such as clavaspirin may equip tunicate haemocytes to mediate cytotoxicity and participate in antimicrobial defence.
authors: Department of Life Science, Hoseo University, Asan City, South Korea.
authors: I H
authors: IH
authors: Lee
authors: C
authors: C
authors: Zhao
authors: T
authors: T
authors: Nguyen
authors: L
authors: L
authors: Menzel
authors: A J
authors: AJ
authors: Waring
authors: M A
authors: MA
authors: Sherman
authors: R I
authors: RI
authors: Lehrer
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D001483:Base Sequence; D001798:Blood Proteins / Q000737:chemistry; D015152:Blotting, Northern; D002463:Cell Membrane Permeability; D002942:Circular Dichroism; D003001:Cloning, Molecular; D006461:Hemolysis; D006801:Humans; D008081:Liposomes / Q000378:metabolism; D008826:Microbial Sensitivity Tests / Q000379:methods; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000235:genetics* / Q000494:pharmacology*; D017386:Sequence Homology, Amino Acid; D017550:Spectroscopy, Fourier Transform Infrared; D014561:Urochordata
chemical_list: D000900:Anti-Bacterial Agents; D001798:Blood Proteins; D008081:Liposomes; D010455:Peptides; C106713:clavanin A; C464761:clavaspirin