Exploring the five-paced viper () venom proteome by integrating a combinatorial peptide ligand library approach with shotgun LC-MS/MS.

BACKGROUND

Snake venoms are complex mixtures of toxic proteins or peptides encoded by various gene families that function synergistically to incapacitate prey. In the present study, in order to unravel the proteomic repertoire of venom, some trace abundance components were analyzed.

METHODS

Shotgun proteomic approach combined with shotgun nano-LC-ESI-MS/MS were employed to characterize the medically important venom, after collected samples were enriched with the combinatorial peptide ligand library (CPLL).

RESULTS

This avenue helped us find some trace components, undetected before, in venom. The results indicated that venom comprised 84 distinct proteins from 10 toxin families and 12 other proteins. These results are more than twice the number of venom components obtained from previous studies, which were only 29 distinct proteins obtained through RP-HPLC for the venom of the same species. The present results indicated that in venom, the most abundant components (66.9%) included metalloproteinases, serine proteinases, and C-type lectin proteins; the medium abundant components (13%) comprised phospholipases A (PLA) and 5'-nucleotidases and nucleases; whereas least abundant components (6%) were aminopeptidases, L-amino acid oxidases (LAAO), neurotoxins and disintegrins; and the trace components. The last were undetected before the use of conventional shotgun proteomics combined with shotgun nano-LC-ESI-MS/MS, such as cysteine-rich secretory proteins Da-CRPa, phospholipases B-like 1, phospholipases B (PLB), nerve growth factors (NGF), glutaminyl-peptide cyclortransferases (QC), and vascular non-inflammatory molecules 2 (VNN2).

CONCLUSION

These findings demonstrated that the CPLL enrichment method worked well in finding the trace toxin proteins in venom, in contrast with the previous venomic characterization of by conventional LC-MS/MS. In conclusion, this approach combined with the CPLL enrichment was effective for allowing us to explore the hidden venomic profile and extended the list of potential venom toxins.