title: Further isolation and characterization of grammistins from the skin secretion of the soapfish Grammistes sexlineatus.
abstract: Soapfishes contain peptide toxins (grammistins) in the skin secretion. Two grammistins (Gs 1 and Gs 2) and six grammistins (Pp 1, Pp 2a, Pp 2b, Pp 3, Pp 4a and Pp 4b) have already been isolated from Grammistes sexlineatus and Pogonoperca punctata, respectively. In this study, five grammistins (Gs A-E), together with grammistins Gs 1 and Gs 2, were further isolated from G. sexlineatus by gel filtration and reverse-phase HPLC. Sequence analyses revealed that grammistins Gs A (28 residues) and Gs C (26 residues) are analogous to grammistin Pp 3 and grammistin Gs B (12 residues) to grammistin Pp 1, while grammistins Gs D (13 residues) and Gs E (13 residues) are identical with grammistins Pp 1 and Pp 2b, respectively. Grammistins Gs A-C exhibited antibacterial activity with a broad spectrum against nine species of bacteria in common with the other grammistins but had no hemolytic activity differing from the other grammistins. Grammistins Gs A-E, Gs 1 and Gs 2 could release carboxyfluorescein entrapped within liposomes made of either phosphatidylcholine or phosphatidylglycerol/phosphatidylcholine (3:1), demonstrating their membrane-lytic activity. However, no clear relationship between the membrane-lytic activity and the biological activity of grammistins was recognized.
authors.affiliation: Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Konan-4, Minato-ku, Tokyo 108-8477, Japan.
authors.forename: Nami
authors.initials: N
authors.lastname: Sugiyama
authors.forename: Mika
authors.initials: M
authors.lastname: Araki
authors.forename: Masami
authors.initials: M
authors.lastname: Ishida
authors.forename: Yuji
authors.initials: Y
authors.lastname: Nagashima
authors.forename: Kazuo
authors.initials: K
authors.lastname: Shiomi
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000900:Anti-Bacterial Agents / Q000633:toxicity*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D005397:Fish Venoms / Q000235:genetics* / Q000378:metabolism / Q000633:toxicity*; D005452:Fluoresceins / Q000378:metabolism; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects; D008081:Liposomes / Q000378:metabolism; D008969:Molecular Sequence Data; D010473:Perciformes / Q000235:genetics / Q000378:metabolism*; D020539:Sequence Analysis, Protein; D012867:Skin / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D005397:Fish Venoms; D005452:Fluoresceins; D008081:Liposomes; C024098:6-carboxyfluorescein; C001882:grammistin