title: Nanospray analysis of the venom of the tarantula Theraphosa leblondi: a powerful method for direct venom mass fingerprinting and toxin sequencing.
abstract: Mass spectrometric methods, including matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOFMS), on-line liquid chromatography/electrospray ionisation mass spectrometry (LC/ESI-MS), and nanospray ionisation/hybrid quadrupole time-of-flight mass spectrometry (nanoESI-QqTOFMS), were applied to characterize by mass fingerprinting the venom of the French Guyanese tarantula Theraphosa leblondi. Of these techniques direct nanoESI-QqTOFMS, which allowed the detection of 65 protonated molecules with high mass accuracy, appeared to give the best results. Three major peptides, TlTx1, TlTx2 and TlTx3, were sequenced using a combination of nanoESI-MS/MS and enzyme digestion/MS and MS/MS experiments. Each sequence was confirmed by automated Edman sequencing. In patch-clamp experiments these peptides were found to have a specific inhibitory effect on the voltage-dependent potassium channel, Kv4.2.
authors.affiliation: UMR CNRS 8587, Laboratoire Analyse et Environnement, Institut des Sciences, Université d'Evry Val-d'Essonne, Bd. François Mitterrand, 91024 Evry Cedex, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Legros
authors.forename: Marie-Louise
authors.initials: ML
authors.lastname: Célérier
authors.forename: Maud
authors.initials: M
authors.lastname: Henry
authors.forename: Catherine
authors.initials: C
authors.lastname: Guette
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D066298:In Vitro Techniques; D013058:Mass Spectrometry / Q000379:methods; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D026902:Potassium Channel Blockers / Q000737:chemistry / Q000633:toxicity; D015221:Potassium Channels / Q000187:drug effects; D024642:Potassium Channels, Voltage-Gated; D051672:Shal Potassium Channels; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods; D013111:Spider Venoms / Q000737:chemistry* / Q000235:genetics / Q000633:toxicity; D013112:Spiders / Q000737:chemistry / Q000235:genetics
chemical_list: D026902:Potassium Channel Blockers; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D051672:Shal Potassium Channels; D013111:Spider Venoms