title: Toxicity and partial structure of a hepatotoxic peptide produced by the cyanobacterium Nodularia spumigena Mertens emend. L575 from New Zealand.
abstract: A clonal isolate, termed L575, of the filamentous brackish-water cyanobacterium Nodularia spumigena Mertens emend. was found to produce a potent hepatotoxic peptide (50% lethal intraperitoneal dose for the mouse, 60 micrograms/kg) with chemical and toxicological properties similar to those of the hepatotoxic heptapeptides produced by other freshwater planktonic cyanobacteria. The isolate was made from a water sample collected in Lake Ellesmere, New Zealand, in 1980. The toxin, isolated and purified by high-performance liquid chromatography (HPLC) and analyzed by HPLC amino acid analysis, contained glutamic acid, beta-methyla-spartic acid, and arginine units in equivalent amounts. The fast-atom-bombardment mass spectrum of the toxin indicated the molecular weight to be 824. Batch cultures of strain L575 showed that the toxin content varied between 1.96 and 2.99 mg/g of cells and that a positive correlation between toxin content and chlorophyll a, but not biomass, was present.
mesh_terms: D000818:Animals; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D000458:Cyanobacteria / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D005618:Fresh Water; D008099:Liver / Q000187:drug effects*; D008297:Male; D013058:Mass Spectrometry; D051379:Mice; D008855:Microscopy, Electron, Scanning; D009520:New Zealand; D010455:Peptides / Q000032:analysis / Q000302:isolation & purification* / Q000633:toxicity; D014118:Toxins, Biological / Q000032:analysis / Q000302:isolation & purification* / Q000633:toxicity; D014871:Water Microbiology
chemical_list: D010455:Peptides; D014118:Toxins, Biological