Paul Abraham
Description of Research:
In recent years, increasing economical and environmental concerns associated with the dependency on fossil fuels has led to the introduction of government policies that support research on the conversion of the chemical energy stored in plant-derived starch to ethanol. Starch is a non-complex polymer of glucose that can be readily converted to ethanol with existing technology, but the current chemical energy yield is low; about one-third of the chemical energy is lost in producing ethanol. Corn-based ethanol production has raised concerns, such as fertilizer runoff, fuel competing with food, and potent greenhouse gases. Thus, a major effort has begun to develop alternative feedstocks for ethanol by using crop residues, perennial grasses, and other forms of plant biomass that are collectively termed “lignocellulosics.” This form of biomass presents a major challenge in the accessibility of its sugars; it is not readily converted to ethanol because the biomass is locked in a complex polymer composite that consists of a mixture of lignin, hemi-cellulose and cellulosic fibers. The architecture of this complex polymer was elegantly created to be recalcitrant, resisting natural chemical and biological degradation. By solving the recalcitrance of crystalline cellulose, there will be a dramatic cut in processing costs, which will in turn allow the renewable source of energy to be implemented into current fuel infrastructure. A large-scale, integrated, interdisciplinary approach for developing innovative energy crops has been launched by the Bioenergy Science Center (BESC) in Oak Ridge National Laboratory. One of the center’s specific aims is dedicated to understanding plant cell-wall molecular and physical structures are synthesized, maintained, and deconstructed. In almost every one of these processes it is the enzymatic catalysis, molecular signaling, and physical interactions of proteins that reflect the biological and chemical activity of the cell under various conditions. While genomics sheds light on the on/off state of various proteins being expressed and transcriptomics reveals what messages are being transcribed, proteomics reflects the active functional components of a cell at a specific time and condition. Obtaining deep protein-level measurements, such as identification, quantification, post-translational modification and localization, facilitates a more comprehensive understanding of key biological components. My research has focused on conducting proteomic measurements on both potential feedstocks and microbial communites capable of degrading lignocellulose. The measurements are performed in a high-throughput manner using two-dimensional liquid chromatography (2D-LC) coupled with tandem mass spectrometry (MS/MS). Proteomic measurements can be performed by beginning with proteins that are either enzymatically digested into peptides prior to mass analysis (bottom-up approach) or analyzed as an intact protein (top-down approach). When tackling high-complexity samples for large-scale analysis the bottom-up approach is the most popular. Also known as “shotgun” proteomics, this technique provides a vast proteome dataset that requires a considerable amount of effort to translate the data output in a cell biology context.
Contact Information
Paul Abraham
Prospective PhD Candidate, Class of 2008
Email: pabraham@utk.edu
Mentor
Dr. Robert Hettich
Degree
BS: BCMB, University of Tennessee