What does the future hold for top down mass spectrometry?

Abstract

Mass spectrometry (MS) research has revolutionized modern biological and biomedical fields. At the heart of the majority of mass spectrometry experiments is the use of Bottom Up mass spectrometry methods where proteins are first proteolyzed into smaller fragments before MS interrogation. The advent of electron capture dissociation and, more recently, electron-transfer dissociation, however, has allowed Top Down (analysis of intact proteins) or middle down (analysis of large polypeptides) mass spectrometry to both experience large increases in development, growth, and overall usage. Nevertheless, for high-throughput large-scale proteomic studies, Bottom Up mass spectrometry has easily dominated the field. As Top Down mass spectrometry methodology and technology continue to develop, will it genuinely be able to compete with Bottom Up mass spectrometry for whole proteome analysis? Discussed here are the current approaches, applications, issues, and future view of high-throughput Top Down mass spectrometry. (J Am Soc Mass Spectrom 2010, 21, 193-202)

Analytical characterization of NOTA-modified somatropins

“…In combination with MS, precise and complementary information is generated. In this direct analytical approach, intact protein molecular ions generated by electrospray (ESI) or matrix-assisted laser desorption (MALDI) are introduced into the mass analyzer [57].…”

Top-Down Atmospheric Ionization Mass Spectrometry Microscopy Combined With Proteogenomics

“…Conventional experience has shown precursors of higher charge state are prone to give more informative ion products, as each peptide fragment has higher probability to possess charges so as to be measured by mass spectrometers. 60 High charge state precursor is also essential for a higher level tandem mass analysis (MS n , n>2). Thus, we collected homogenate of 10 pairs of adult sex ganglia (SG5 and SG6) to extract the sex peptides for subsequent nanoESI MS measurements.…”

Chemical and biochemical approaches in the study of histone methylation and demethylation

“…This approach has proved to be particularly useful for the MS characterization of histone methylation and other modifications because histone tails containing the majority of modifications can be proteolytically generated and purified as a single piece of peptide for MS analysis. [151][152][153][154] The N-terminal tails with less than 50 amino acid residues are usually produced from digestion by endoproteases such as Glu-C, Asp-N, Arg-C or trypsin after unmodified lysine residues are protected by derivatization. Subsequent MS/MS analysis of these tails is able to characterize the modifications on histones.…”