Proteomic and glycomic analysis of human plasma using ion mobility-mass spectrometry

The emerging fields of proteomics and glycomics hold promise as a means of discovering disease-specific biomarkers. Human plasma serves as a possible medium for this discovery process because it could contain signatures for all possible proteins. However, the analysis of plasma proteins and their modifications is difficult because the large number of proteins and their widely ranging abundances currently exceeds the capabilities of any single analytical technique.;The focus of this work is the development of ion mobility spectrometry (IMS) and mass spectrometry (MS) techniques for the analysis of the human plasma proteins and glycans. IMS-MS techniques add an extra dimension of separation prior to MS analysis that separates ions based on their overall shape and charge. IMS-MS techniques can increase the number of resolvable components in a mixture. The work begins with the development of methods for the proteomic analysis of plasma that combines strong-cation-exchange chromatography (SCX) and reverse-phase liquid chromatography (LC) with IMS-MS. I then consider the analysis of N-linked glycans from human plasma. Glycosylation is a frequent modification and has been linked to diseases. Combined multidimensional ion mobility separations (IMS-IMS-MS) and molecular modeling techniques revealed that determining the isomeric composition of select N-linked glycans was possible. Finally, high-throughput IMS-MS analysis in combination with principal component analysis (PCA) demonstrated that changes in the mobility distribution of N-linked glycans could be used to differentiate serum samples that came from patients affected by liver disease, such as cancer or cirrhosis, from control samples.