Resurrexit, sicut dixit, alleluia. Snake venomics from a 26-years old polyacrylamide focusing gel

Abstract

A 26-year-old dried polyacrylamide gel, cast in presence of an immobilized pH gradient and containing focused proteins from the venoms of a northern black-tailed rattlesnake (Crotalus molossus molossus), and of a western diamondback rattlesnake (Crotalus atrox) has been screened in order to see the feasibility of extracting the proteins, analyzing thembymass spectrometry (MS) and assessing their integrity.Nine gel bandswere excised along the pH 3–10 gradient and the gel segments reswollen inwarmacetonitrile. Upon digestion andMSanalysis, all the bands could be identified and attributed to the respective venoms of the two rattlesnake species. Although a few peptides exhibited modified amino acids, the proteins were found to be well preserved even upon such a long storage at room temperature. The present data suggest the feasibility of identifying proteins from very old samples trapped in polyacrylamide gels, and analyzed in a pre-mass spectrometry era, thus of uncertain identity.