Associate Professor Lloyd W. Sumner

Lloyd W. Sumner, Ph.D

Associate Professor

Noble Researcher since 1999

lwsumner@noble.org

Sumner Group

Ph.D., Analytical Chemistry, 1993, Oklahoma State University

Research emphasis: Bioanalytical Chemistry and Mass Spectrometry

Mass spectrometry (MS) is the science of "weighing" individual atoms and molecules using sophisticated instruments. These instruments produce gas-phase analyte ions from samples originating in the solid, liquid or gas phase. Once gas-phase ions are generated, they are subjected to eletrostatic and magnetic fields that differentiate and detect each ion according to its mass-to-charge ratio (m/z). "Molecular weight" information obtained from these experiments is very specific and highly useful in chemical identification and characterization. Advances in the ability of mass spectrometers to "weigh" increasingly larger molecules more precisely now allows us to mass measure peptides, proteins, and other high mass biomolecules very accurately.

The research focus of our group centers on the development, advancement, and application of leading-edge instrumental techniques for the large-scale profiling and identification of the functional products of gene expression, namely proteins and metabolites. Profiling large numbers of proteins (Proteomics) and large numbers of metabolites (Metabolomics) provides a high resolution view of the biochemical phenotype. Comparative profiling provides detailed quantitative and qualitative data that are highly valuable in gene validation, gene discovery, mechanistic insights, and a better understanding of the cellular response of an organism to external stimuli. Correlation of the expression profiles with genetic information also provides a unique way of understanding gene function and the interrelationships between genes. The task of profiling large numbers of proteins and metabolites simultaneously is still quite challenging; however we are approaching these challenges using mass spectrometry (MS) coupled with advanced separation technologies. Information obtained from these experiments is very specific and highly useful in chemical identification and characterization. Currently, we utilize high resolution two-dimensional gel electrophoresis (2-DE), high performance liquid chromatography (HPLC/MS), ultra performance liquid chromatography (UPLC-MS) and gas chromatography (GC/MS) to profile, compare and identify Medicago truncatula proteins and metabolites. Our research interests also seek to better understand the physical and chemical aspects of the many technologies being used in our laboratory. We want to use this understanding to improve and/or develop novel technologies.

The Noble Foundation Biological Mass Spectrometry facility is both a basic research laboratory and a resource for the Noble Foundation. The Biological Mass Spectrometry Facility is working in cooperation with the newly created Center for Medicago Genomics Research to correlate protein and metabolite expression with genetic expression monitored through expressed cDNA and oligonucleotide microarrays for discovery and insight into the mechanisms of cell life. Correlations will be assisted with bioinformatic tools being developed at The Virginia Bioinformatics Institute, The National Center for Genomic Resources and internally.