John A. Lewis US Army Center for Environ. Health Res. Office: 301-619-7209 FAX: E-mail: john.lewis@det.amedd.army.mil Job Title: Research Biologist Ph.D. in Biology from the University of Pittsburgh

Speaker: John A. Lewis, US Army Center for Environmental Health Research (USACEHR), Fort Detrick, Frederick, MD 21701

Topic: Computational Approaches for Quanititative Proteomics

Place: Building 549, Conference Room B, NCI at Frederick, Frederick, MD

Time: Tuesday, October 18, 2005, at 2:00 PM

Abstract: Mass spectrometers have proven to be an invaluable tool for identification of proteins and are the foundation of modern proteomics. Recent efforts in the field have been directed at developing methods that accurately quantify differences in protein abundance between different biological states. Though much of the recent quantitative analysis work has focused on isotopic labeling, computational methods which use extracted ion counts to determine relative quantification between samples show promise. We have evaluated several computational approaches to cross-sample quantification. Our initial work using in-house software showed that reproducible, linear changes in ion abundance that correspond to protein concentrations could be identified in controlled samples. Through a CRADA, our partner developed more sophisticated software that more effectively identifies, quantifies and compares peptide peaks between runs. Two new commercially available packages have also been tested and shown to be effective.

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