A SYSTEM AND METHOD FOR AUTOMATIC PROTEIN SEQUENCING BY MASSSPECTROMETRY

摘要

A method of deducing the sequence of a protein by analysing tandem mass spectrometry data. The protein is subjected to partial isotopic labelling by enzymatic digestion in a water mixture comprising a non-natural abundance of H21sO. Differential scanning mass spectrometry is applied to the peptide fragments obtained from the digestion. Peaks in the spectra are analyzed to ascertain whether they arise from isotopically labeled fragments or not. A filtered spectrum is calculated that just comprises peaks from the y-ions. T he sequence of the peptide is deduced by computing the difference in the mass between adjacent y-ion peaks.