Fig. 2.
Detection without synthetic peptides is possible with strong ion signals. NS1122–130 peptides AIMDKNIIL from IAV strain A/Puerto Rico/8/1934 and AIMDKNIML from IAV strain A/Victoria/3/1975 are detected using numerical models. (A) Poisson detection chromatogram for AIMDKNIIL in sample of Fig. 1 uses a simple model of fragmentation (three b-type ions). (B) Elution mapping using normalized elution time (NET) Prediction Utility. The identified elution positions of some endogenous peptides (black dots) and detected IAV peptides (red squares) are plotted as a function of calculated retention time. Yellow triangle is scan position of XIC/Poisson coincidence in A plotted against predicted retention time. (C and D) MS2 spectra at elution peak for NS1122–130 peptides in PR8 and Victoria strain infections identifies each peptide by sequence ions.