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Professor Emeritus, Analytical Chemistry
B.S. 1965, Pennsylvania State University
Ph.D. 1972, University of Michigan
Email: jwebb@ilstu.edu
Phone: (309)438-2604
Office: 217 Science Laboratory Building
Proteomics and Mass Spectrometry
Proteomics, a growing field
of biochemical research, attempts to catalog and characterize proteins expressed by genes,
compare variations in their expression levels under different conditions
(notably sickness versus health), study their interactions, and identify their
functional roles. Proteomics, in a sense, is more complex than genomics, not
only because there are so many possible interactions among proteins, but because
there are so many more proteins than genes. Although, the humane genome project
has identified more than 30,000 genes, the proteins encoded by these genes
amount to more than half million.
During the past two decades, mass spectrometry has become established as the primary method for protein
identification from complex mixtures of biological origin. This is largely
attributable to advances in ionization techniques and instrumentation that allow
routine analysis of minute amounts (typically femtomoles) of nonvolatile, polar
compounds such as peptides and proteins.
In our laboratory, we are interested
in characterizing proteins and their post-translational modifications by liquid
chromatography/mass spectrometry (LC/MS).
Currently, we are involved in a collaborative project with Professor Jon
Friesen to identify the phosophorlyation sites in the enzyme
CTP:phosphocholine cytidylyltransferase (CT),
Phosphorlyation is important because it is a major control mechanism for the
regulation of diverse cellular processes.
Our approach to this problem is to
digest the protein into smaller peptides using a suitable enzyme. The peptides
are then separated by HPLC and their molecular weight determined by MS. The
addition of a phosphate group can then be determined.
In addition to the
instrumentation at Illinois State University, we are making use of the
sophisticated mass spectrometric facilities at the University of California, San Francisco to
help us in this research.
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