This program assists in the interpretation of MS and MS/MS spectra of peptides. Pepfrag can calculate:

• the molecular weight (MW) of the peptide
• the m/z value of the [M+H]+ ion of the peptide
• the m/z value of the common fragment ions (a,b,c,x,y,z) observed during MS/MS of the peptide

Fragment ions can be sorted by mass or by ion type (in ascending or descending order).

An auto-fill option is available for entering common peptide sequences.

Use

• To use the program simply enter the peptide sequence in the field on the opening page. Use the single letter amino acid code (upper or lower case). There is also an auto-fill option in the menu for common peptide sequences.

• Then press the button for "Calc MW" or "Induce Fragmentation".

• NOTE: Mono-isotopic masses are used in all the calculations.

• If "CalcMW" is pressed the MW of the peptide is displayed on the screen.

• If "Induce Fragmentation" is pressed a new form is opened displaying the m/z values of the fragment ion types chosen on the opening screen. On this page it is possible to choose the sort type and order for the display of the fragments.

• Currently the program is limited to 20 residue and less peptides.

• All program state variables are saved upon program termination.

• Please note: No guarantees are made about the accuracy of the data reported by Pepfrag. I am quite confident in the values reported, however, I am not responsible for errors or misidentifications due to those errors.

Author : Ryan M. Danell

Compatibility

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