Our goal is to develop vacuum ultraviolet circular dichroism (VUCD) as a structural tool for conformational studies of biopolymers in general, and carbohydrates (polysaccharides) in particular. The general approach has been to combine experimental and theoretical methods where applicable. During the next three years VUCD spectra of selected polysaccharides will be obtained, which will allow a delineation of the contributions of the various factors which determine VUCD spectra; e.g., interresidue rotational angles, anomeric configuration, linkage type, protonation, substituent groups, and hydrogen bonding. Polysaccharides to be studied include xylan, carrageenan, xanthan, galactan, polymannuronate and polyguluronate. VUCD measurements will also be extended to include glycoproteins. Fibronectin plays a role in cell adhesion, cell migration and embryonic differentiation. It exhibits affinities for heparin and other macromolecules, and the interactions are known to have their origin in discrete domains of the fibronectin molecule. Fibronectin has little, if any, helical structure. We will use VUCD spectroscopy to probe the native conformation, and the conformational changes that occur upon heparin binding. Model theoretical calculations will be carried out to determine the origin of a recently discovered sector rule which successfully accounts for the sign of the VUCD in all polysaccharide systems studied to date. Exciton contributions and the role of Sigma-Sigma* transitions to polysaccharide VUCD will be evaluated. The objective of these calculations is to develop a theoretical basis for interpreting polysaccharide VUCD.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM024862-08
Application #
3272580
Study Section
Biophysics and Biophysical Chemistry A Study Section (BBCA)
Project Start
1979-09-01
Project End
1989-06-30
Budget Start
1987-07-01
Budget End
1988-06-30
Support Year
8
Fiscal Year
1987
Total Cost
Indirect Cost
Name
State University of NY, Binghamton
Department
Type
Schools of Arts and Sciences
DUNS #
090189965
City
Binghamton
State
NY
Country
United States
Zip Code
13902
Sathyanarayana, B K; Stevens, E S (1988) Semiempirical, sodium-D molar rotations of pyranosides and other carbohydrate model compounds. Carbohydr Res 181:223-8
Stevens, E S; Lin, B (1987) Vacuum ultraviolet circular dichroism of keratan sulfate. Biochim Biophys Acta 924:99-103
Stevens, E S; Morris, E R; Charlton, J A et al. (1987) Vacuum ultraviolet circular dichroism of fibronectin. Dominant tyrosine effects. J Mol Biol 197:743-5
Stevens, E S; Sathyanarayana, B K (1987) Conformation of (1----6)-beta-D-glucan by vacuum-ultraviolet circular dichroism. Carbohydr Res 160:131-5
Stevens, E S; Sathyanarayana, B K (1987) A semiempirical theory of the optical activity of saccharides. Carbohydr Res 166:181-93
Stevens, E S (1986) Vacuum UV circular dichroism of polysaccharides. Photochem Photobiol 44:287-93
Winter, W T; Taylor, M G; Stevens, E S et al. (1986) Solid-state 13C NMR and X-ray diffraction of dermatan sulfate. Biochem Biophys Res Commun 137:87-93
Sathyanarayana, B K; Stevens, E S; Texter, J (1985) Random-phase calculation of the low-energy circular dichroism in glucans. Biopolymers 24:1365-83