Assignment of the reverse-phase fractions from the venoms of <i>Sistrurus miliarius streckeri</i> (Sms) and <i>S. m. miliarius</i> (Smm), isolated respectively as in Figs.1 and 2, to protein families by N-terminal Edman sequencing, mass spectrometry, and collision-induced fragmentation by nESI-MS/MS of selected peptide ions from in-gel digested protein bands separated by SDS-PAGE (inserts in Figs. 1 and 2).

Apparently identical proteins in Sms and Smm venoms are labelled with the same number. In MS/MS-derived sequences, X = Ile or Leu; Z, pyrrolidone carboxylic acid; B, Gln or Lys. Unless other stated, for MS/MS analyses, cysteine residues were carbamidomethylated; Molecular masses of native proteins were determined by electrospray-ionization (±0.02%) or MALDI-TOF (±0.2%) mass spectrometry. Apparent molecular masses were determined by SDS-PAGE of non-reduced (▪) and beta-mercapethanol-reduced (♦) samples. np, non-peptidic material found; ND, not determined.