Chemical Sciences: A Manual for CSIR-UGC National Eligibility Test for Lectureship and JRF/Bottom-up proteomics

right|350px|thumb|Bottom-up versus top-down proteomics Bottom-up proteomics is a common method to identify proteins and characterize their amino acid sequences and post-translational modifications by proteolytic digestion of proteins prior to analysis by mass spectrometry.Aebersold R, Mann M Mass spectrometry-based proteomics Nature 422 6928 198–207 2003 March 12634793 10.1038/nature01511 Chait BT Chemistry. Mass spectrometry: bottom-up or top-down? Science 314 5796 65–6 2006 17023639 10.1126/science.1133987 The proteins may first be purified by a method such as gel electrophoresis resulting in one or a few proteins in each proteolytic digest. Alternatively, the crude protein extract is digested directly, followed by one or more dimensions of separation of the peptides by liquid chromatography coupled to mass spectrometry, a technique known as shotgun proteomics.Washburn MP, Wolters D, Yates JR Large-scale analysis of the yeast proteome by multidimensional protein identification technology Nat. Biotechnol. 19 3 242–247 2001 11231557 10.1038/85686 Wolters DA, Washburn MP, Yates JR An automated multidimensional protein identification technology for shotgun proteomics Anal. Chem. 73 23 5683–5690 2001 11774908 10.1021/ac010617e By comparing the masses of the proteolytic peptides or their tandem mass spectra with those predicted from a sequence database, peptides can be identified and multiple peptide identifications assembled into a protein identification. References