Purpose: To understand the fragment ions of MS/MS.

 

  1. Download the following data files:

Iontrap1, Iontrap2, Iontrap3, QTof1, QTof2, QTof3

2.      Select one of the data with peptide sequence as file name. Manually label all the y-ions and some b-ions in the spectra.

3.      Observe the y-H2O and y-NH3 ions.

4.      Observe the relation between y and b ions (y+b compared with precursor ion mass)

5.      Use the server at bioinfor.com/peaksonline to do de novo sequencing and database search for the files.  Make sure that you’re using the right parameters for iontrap and qtof data.

6.      Zip the qtof data into a single zip and use peaksonline to do them all together.