Fig. 1

General types of analytical bottom-up strategies employed in the proteomic profiling of snake venoms. a Gel-based strategies involve the separation of the venom proteins by two-dimensional gel electrophoresis (2DE) followed by staining and spot picking. Protein spots are then in-gel digested (usually with trypsin, scissors icon) and the resulting proteolytic peptides submitted to tandem mass spectrometry (MS/MS) analysis. b Liquid-chromatography (LC)-based strategies (shotgun proteomics) digest the whole venom with trypsin and separate the resulting peptides usually by multidimensional nano-flow HPLC, hyphenated to MS/MS analysis. c The combined strategy of ‘snake venomics’ takes advantage of the opportunity of performing the fractionation and the quantification of the venom components in the same reversed-phase chromatography step. A second step of separation and quantification is performed by SDS-PAGE followed by gel densitometry. Protein bands are excised, in-gel digested with trypsin, and submitted to MS/MS analysis