PRIMARY FACULTY

Robert Williams, Ph.D.
Associate Professor
Biochemistry
 
4301 Jones Bridge Road
Bethesda MD 20814
Office: 301-295-3568
Fax: 301-295-1996
rwilliams@usuhs.mil

Vibrational Spectroscopy Of Peptides And Proteins
 
We have two principle goals. The first is to develop methods for using vibrational spectroscopy to obtain information about protein and peptide structure. The second is to use these methods to measure protein and peptide secondary structure refolding kinetics in a time range starting at about 50 microseconds after the initiation of the folding reaction.
 
In pursuit of this first goal, we calculate the vibrational frequencies of a peptide or protein with a combination of ab initio and normal mode methods, using supercomputers in our laboratory and at the National Cancer Institute, and compare the results with experimental measurements of the vibrational spectra. The combined computational and experimental approach yields the vibrational force constants that will be useful in interpreting the vibrational spectra of proteins.
 
The focus of our second goal is the development of a diamond temperature jump FT-IR sample cell that will be able to change the temperature of a protein sample from 60 degrees to 20 degrees in 50 microseconds. This cell will increase the time range in which the protein refolding reaction can be studied by almost two orders of magnitude. Measurements of protein folding have never been made in the time range. FT-IR measurements will be made using a step-scan FT-IR instrument capable of kinetics measurements in the nanosecond time range.

Selected Publications

Resources