on 05-01-201210:32 AM - edited on 10-15-202111:46 AM by AnalyteGuru
Dauly C, Escoubas P, King GF, Nicholson GM. Application Note 511 Animal venoms are natural libraries of biologically active peptides. They encompass a wide variety of structures and pharmacological activities and represent an enormous resource of novel molecules to be used as insecticide, therapeutic and drug models. Australian funnel web spiders contain many hundreds of peptides that follow a bimodal distribution, with about 75% of the peptides ranging from 3,000 to 5,000 Da1. Although the up-to-date, funnel-web spiders protein database contains about 100 sequences, it was shown recently that the number of peptides present in venom is in the high hundreds. Venom profiling by high resolution and accurate-mass (HR/AM) LC-MS/MS can therefore be used for species identification and to indicate the presence of potentially unknown toxins. Combining MS-based peptide sequence tags with cutting-edge transcriptomics studies and the ability to generate full peptide sequences using molecular biology techniques such as RACE (Rapid Amplification of Complementary Ends) will allow the generation of large peptide sequence libraries that can be mined for drug discovery purposes, in a global approach termed “venomics”. The Thermo Scientific LTQ Orbitrap XL ETD hybrid mass spectrometer is a versatile instrument that allows the fragmentation of peptides and proteins by several different dissociation techniques including collision induced dissociation (CID), higher-energy collisional dissociation (HCD) and electron transfer dissociation (ETD) (Figure 1). Large
peptides require a high resolving power to achieve isotopic resolution of intact parent ions and MS/MS product ions that can then be utilized for de novo sequencing. In this study a combination of HCD and ETD was used to generate MS/MS spectra with high fragment ion coverage to characterize a funnel-web spider venom peptidome and to demonstrate that de novo sequencing with HR/AM spectrometry is applicable to venomics research.