Mass analysis of a distinct peptide from the G3L protein using Method 5 (MALDI-TOF/TOF). The membrane-enriched fraction of the virion was subjected to trypsin digest, and analyzed by MALDI-TOF/TOF MS. The full scan mass spectrum yielded a singly charged ion at m/z 1522.69 (inset). Tandem mass spectrum of the parent ion corresponds to a peptide of G3L. Asterisks (*) denote the loss of ammonia (NH3) or water (H2O).