Dr. Ying Ge, University of Wisconsin-Madison

Comprehensive Analysis of Protein Modifications by Top-down Mass Spectrometry-Based Proteomics

Posttranslational modifications (PTMs), the covalent modifications of a protein after its translation, can alter the physical/chemical properties of a protein and modulate its activity, stability, and function. Aberrant PTMs are believed to be one of the underlying mechanisms for many human diseases. Hence a comprehensive study of protein PTMs is of paramount importance but presents tremendous challenges due to the extreme complexity and heterogeneity of PTMs. We aim to address such challenges by developing an integrated top-down comparative proteomics platform featuring ultra high resolution mass spectrometry (MS) and multidimensional chromatography for characterization and quantification of protein modifications. Top-down MS directly analyzes intact proteins providing a “bird’s eye view” to observe all types of modifications simultaneously in one spectrum. We have shown that top-down MS with electron capture dissociation has unique advantages in unraveling the molecular complexity, quantifying multiple modified protein forms, complete mapping of modification sites with full sequence coverage, discovering unexpected modifications, identifying/quantifying positional isomers and determining the order of multiple modifications. Furthermore, we are employing the top-down comparative proteomics technologies we have developed to decipher the modifications in myofilament proteins using clinical human heart tissues, animal models of heart failure, and recombinant proteins to establish a causal relationship between protein PTMs and cardiac dysfunction in heart failure.

For more information contact Prof. Facundo Fernandez (404-385-4432).