Protein primary structure using orthogonal fragmentation techniques in Fourier transform mass spectrometry.
Proteomics analysis using tandem mass spectrometry requires informative backbone fragmentation of peptide ions. Collision-activated dissociation (CAD) of cations alone is not sufficiently informative to satisfy all requirements. Thus, there is a need to supplement CAD with a complementary fragmentation technique. Electron capture dissociation (ECD) is complementary to collisional excitation in terms of the cleavage of a different bond (N-Calpha versus C-N bond) and other properties. CAD-ECD combination improves protein identification and enables high-throughput de novo sequencing of peptides. ECD and its variants are also useful in mapping labile post-translational modifications in proteins and isomer differentiation; for example, distinguishing Ile from Leu, iso-Asp from Asp and even D- from L-amino acid residues.
Zubarev
Roman
R
Laboratory for Biological & Medical Mass Spectrometry, Uppsala University, Box 583, Uppsala S-751 23, Sweden. roman.zubarev@bmms.uu.se
D000595:Amino Acid Sequence; D005583:Fourier Analysis; D013058:Mass Spectrometry / Q000379:methods*; D010446:Peptide Fragments / Q000737:chemistry* / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism*
D010446:Peptide Fragments; D011506:Proteins