It is proposed to use the methods of physical chemistry to investigate the shapes, motions, and interactions of oligosaccharides and polysaccharides, a class of molecules that is both important and sometimes neglected. The fundamental premise is the recognition that the biologically important conformations of carbohydrates may be members of a diverse, perhaps large, group of nearly equally probable molecular shapes. Globular forms are not known, but secondary structure is common and often of biological significance. Computer based molecular modeling is used to seek useful approximations to the carbohydrate conformational energy surfaces that determine the characteristics of the equilibrium molecular shape distribution. Statistical mechanics is used to describe the contributions from many accessible molecular states to the physically observable properties of the molecules. These theoretical approaches are complemented by experiments designed test the theoretical models. Nuclear magnetic resonance techniques probe both shape and molecular dynamics. Radiation scattering techniques are useful to characterize random coil and ordered forms. Scanning probe microscopy and rheometry are both effective probes of the molecular interactions that contribute to stabilize the biologically active forms.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM033062-17
Application #
6180274
Study Section
Biophysical Chemistry Study Section (BBCB)
Program Officer
Marino, Pamela
Project Start
1983-07-01
Project End
2002-06-30
Budget Start
2000-07-01
Budget End
2001-06-30
Support Year
17
Fiscal Year
2000
Total Cost
$190,874
Indirect Cost
Name
University of California Irvine
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
161202122
City
Irvine
State
CA
Country
United States
Zip Code
92697
McIntire, Theresa M; Lew, Ellen J L; Adalsteins, A Elva et al. (2005) Atomic force microscopy of a hybrid high-molecular-weight glutenin subunit from a transgenic hexaploid wheat. Biopolymers 78:53-61
Jaud, Simon; Tobias, Douglas J; Brant, David A (2005) Molecular dynamics simulations of aqueous pullulan oligomers. Biomacromolecules 6:1239-51
Lee, Hu-Cheng; Brant, David A (2002) Rheology of concentrated isotropic and anisotropic xanthan solutions: 3. Temperature dependence. Biomacromolecules 3:742-53
McIntire, T M; Brant, D A (1999) Imaging of carrageenan macrocycles and amylose using noncontact atomic force microscopy. Int J Biol Macromol 26:303-10
Brant, D A (1999) Novel approaches to the analysis of polysaccharide structures. Curr Opin Struct Biol 9:556-62
Brant, D A; Liu, H S; Zhu, Z S (1995) The dependence of glucan conformational dynamics on linkage position and stereochemistry. Carbohydr Res 278:11-26
Oviatt Jr, H W; Brant, D A (1993) Thermal treatment of semi-dilute aqueous xanthan solutions yields weak gels with properties resembling hyaluronic acid. Int J Biol Macromol 15:3-10
Stokke, B T; Elgsaeter, A; Brant, D A et al. (1993) Macromolecular cyclization of (1-->6)-branched-(1-->3)-beta-D-glucans observed after denaturation-renaturation of the triple-helical structure. Biopolymers 33:193-8
Kadkhodaei, M; Wu, H; Brant, D A (1991) Comparison of the conformational dynamics of the (1----4)- and (1----6)-linked alpha-D-glucans using 13C-NMR relaxation. Biopolymers 31:1581-92
Stokke, B T; Brant, D A (1990) The reliability of wormlike polysaccharide chain dimensions estimated from electron micrographs. Biopolymers 30:1161-81

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