Chemistry Faculty:
James A. de Haseth, Ph.D.
Professor
Phone: 706-542-1968
E-mail: dehaseth@sunchem.chem.uga.edu
Biographical Information
Ph.D., University of North Carolina, 1977
Postdoctoral Fellow, University of Tennessee
Research Interests
Research in this group is directed to a variety of areas. One area is the interface between chromatographic systems and Fourier transform infrared spectrometry. At the present time we have developed interfaces for both liquid chromatography and capillary electrophoresis. The liquid chromatographic interface, or "particle beam," is currently being used to study the secondary conformation of proteins. We are able to use changes that occur on a millisecond time scale, such as the mechanisms of protein folding. We have also developed the first working interface between Fourier transform infrared spectrometry and capillary electrophoresis. We are using this interface to analyze glycoproteins, and in particular, to determine the structure of oligosaccharides. It is clear that infrared spectrometry is beneficial in the determination of the composition and structure of these complex systems. FT-IR spectrometry is used as a detector for oligosaccharide separations. The spectra that are collected contain specific information as to the glycosyl-residue composition of the sample, as well as more complex structure information.
Other areas involve the interaction between stationary phases and enantiomers in the separation of chiral species. To determine the interaction between the solutes and stationary phases, we use step-scanning Vibrational Circular Dichroism (VCD) spectrometry. This method has been highly useful in determination of the mechanisms of chiral separations. Diastereomeric complexes that form between enantiomers and chiral stationary phases have structures that can be probed most successfully with circular dichroic methods. VCD spectrometry is a probe that responds only to functional groups that are directly affected by the chirality of the molecules. Hence, VCD spectrometry is ideally suited to the investigation of the functional groups involved in the formation of the diastereomers.
We also develop and use chemometric methods for the analysis of data. For example, chemometric methods are being developed to help determine the glycosyl-residue composition of oligosaccharides, and eventually, to determine the linkages between the monosaccharides.
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Publications
V.E. Turula, V.E. Bishop, R.D. Ricker, and J.A. de Haseth. "Complete Structure Elucidation of a Globular Protein by Particle Beam Liquid Chromatography/Fourier Transform-Infrared Spectrometry and Electrospray Liquid Chromatography/Mass Spectrometry: Sequence and Conformation of beta-Lactoglobulin," J. Chromatography A 1997, 763, 91.
R.T. Bishop, V.E. Turula, and J.A. de Haseth. "Study of Conformational Effects on RPC Analysis of Proteins with Particle Beam LC/FT-IR Spectrometry and Free Solution Capillary Electrophoresis," Anal. Chem. 1996, 68, 4006.
X. Liang, J.E. Andrews, and J.A. de Haseth. "Resolution of Mixture Components by Target Transformation Factor Analysis and Determinant Analysis for the Selection of Targets," Anal. Chem. 1996, 68, 378.
V.E. Turula and J.A. de Haseth. "Particle Beam LC/FT-IR Spectrometry Studies of Biopolymer Conformations in Reversed-phase HPLC Separations: Native Globular Proteins," Anal. Chem. 1996, 68, 629.