PSP candidate reduction by applying SpliceMet.

Reduction of number of PSP candidates during the progression of SpliceMet step by step. The number of possible PSP detectable in the in vitro digestion of a peptide declines continuously during the consecutive steps of SpliceMet (Figure 1). Here the PSP number reduction observed for the 13mer gp10040–52 and 23mer gp10035–57 is reported both as total number and as a percentage compared to the theoretical PSP number (in brackets). The values are referring to the number of possible PSP at the end of the SpliceMet step. For example, although 5664 PSP could be generated from gp10040–52 assuming 2 as the minimum length of the native PCP (Lext), only 2580 represent the m/z value clusters (obtained with a cluster range of 0.2) that will be matched with the LC-ESI/MS full spectrum at the beginning of step 2. Moreover, up to step 4 the numbers are referred to as the number of m/z values whereas from step 5 they are referred to as the possible sequence because they have been identified by MS/MS.