A comparison of matrix-assisted laser desorption/ionization time-of-flightand liquid chromatography electrospray ionization mass spectrometry methods for the analysis of crude tarantula venoms in the Pterinochilus group

The search for novel pharmacological tools in spider venoms involves the ne ed for precise and reproducible species identification methods. As an addit ion to morphological analysis, we have developed venom fingerprinting by re versed-phase chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) as an efficient and precise venom identification tool. In order to compare the possible use of liquid chromatography electrospray ionization mass spectrometry (LC/ESI-MS) as an additional venom characterization tool, we have applied both methodologies to the study of several tarantula venom samples in the Pterinochilus murinu s group. These species possess highly active venoms yet their taxonomy rema ins difficult, We demonstrate that both methodologies can be successfully a pplied to tarantula venom characterization. MALDI-TOFMS and ESI-MS gave sim ilar overall profiles and allowed fine discrimination of samples. At least one venom sample was proven to belong to a completely different venom group . Coupling of ESI-MS with HPLC separation afforded a new dimension in venom analysis, with clear discrimination between components of similar Mr and g ave a finer picture of venom composition, number of molecular species and m olecular weight distribution, Copyright (C) 1999 John Wiley & Sons, Ltd.