Analysis of intact venom proteins with capillary zone electrophoresis - mass spectrometry

Abstract

In this work we demonstrated the favourable analytical performance of capillary zone electrophoresis coupled with mass spectrometry (CZE-MS) for the intact protein analysis of similar venom samples. Venom provides a characteristic feature (fingerprint) of a given snake. Using 1 M formic acid (pH = 1.9) as background electrolyte, minimal adsorption and narrow peaks shapes - thus good separation efficiencies - were obtained for the protein components of the venom samples. The precision of migration times and peak areas were 1.9–2.8 RSD% and 0.8–7.2 RSD%, respectively and the theoretical plate numbers were 32000–238000 for peaks having signal-to-noise ratio (S/N) larger than 50.More than 250 different neuropeptides (7–10 kDa) were detected in the venoms obtained from snakes of 9 different subspecies (belonging either to Naja or Dendroaspis species). The protein contents of the venoms of the same subspecies collected from different geographical regions are similar and differ only in a few (less than 10 %) components. However, the venoms collected from different subspecies (but from the same species) exhibit very different protein patterns: no matches were found in the molecular weights of proteins.