Figure 3From: Proteomic analysis of sea urchin (Strongylocentrotus purpuratus) spicule matrix MS/MS spectrum of a SM30-D peptide. This spectrum shows the MS/MS analysis of a triply charged peptide confirming the annotated predicted sequence contained in SPU:000828. As to be expected almost all of the major y-ions correspond to preferential cleavages N-terminal to prolines. The N-terminal Gln is cyclized to pyroglutamine. The mass error was 0.11 ppm, the PEP score was 3.01E-46 and the Mascot score was 63. Spectra of other unique peptides are shown in additional file 6.Back to article page