Gangliosides are important components of the cell plasma membrane, especially in nervous tissue where they constitute about 10% of the total lipid. It has been found that gangliosides are involved in the recognition machinery of the cell, cell adhesion, cell-cell interactions and that they serve as receptors for glycopeptide hormone, neuropeptides, bacterial toxins and viruses. This research project is directed to study at the molecular level a major aspect of ganglioside function, namely, the role of gangliosides as cell surface receptors using well defined experimental systems. The molecular details and interactions of cholera toxin (CT) and the heat-labile enterotoxin of E. coli with their receptor ganglioside G(m1) will be studied using an experimental thermodynamic approach. The structural stability of these two proteins and their inter- and intra-subunit interactions will be studied in detail. Particularly, functionally relevant molecular interactions will be identified and their energetics measured using state-of-the-art ultra high sensitivity calorimetric techniques. The modulation of cooperative interactions within the toxin molecule by ganglioside G(M1) lead to: 1) the attachment of the toxin binding subunits to the cell surface; 2) the release of the toxic subunits from the binding subunits of the toxin molecules; and, 3) the subsequent penetration of the toxic subunits into the interior of the target membrane. These studies will provide a detailed quantitative description of the functional energetics of a specific ganglioside receptor.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS024520-08
Application #
3409198
Study Section
Biophysical Chemistry Study Section (BBCB)
Project Start
1986-07-01
Project End
1996-02-29
Budget Start
1993-03-01
Budget End
1994-02-28
Support Year
8
Fiscal Year
1993
Total Cost
Indirect Cost
Name
Johns Hopkins University
Department
Type
Schools of Arts and Sciences
DUNS #
045911138
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Johnson, C R; Angeletti, M; Pucciarelli, S et al. (1996) Oxygen binding to fallow-deer (Dama dama) hemoglobin: stepwise enthalpies at pH 7.4. Biophys Chem 59:107-17
Gomez, J; Freire, E (1995) Thermodynamic mapping of the inhibitor site of the aspartic protease endothiapepsin. J Mol Biol 252:337-50
Freire, E (1995) Thermodynamics of partly folded intermediates in proteins. Annu Rev Biophys Biomol Struct 24:141-65
Hilser, V J; Freire, E (1995) Quantitative analysis of conformational equilibrium using capillary electrophoresis: applications to protein folding. Anal Biochem 224:465-85
Freire, E (1995) Thermal denaturation methods in the study of protein folding. Methods Enzymol 259:144-68
Murphy, K P; Freire, E (1995) Thermodynamic strategies for rational protein and drug design. Pharm Biotechnol 7:219-41
Gomez, J; Hilser, V J; Xie, D et al. (1995) The heat capacity of proteins. Proteins 22:404-12
Murphy, K P; Freire, E; Paterson, Y (1995) Configurational effects in antibody-antigen interactions studied by microcalorimetry. Proteins 21:83-90
Johnson, C R; Morin, P E; Arrowsmith, C H et al. (1995) Thermodynamic analysis of the structural stability of the tetrameric oligomerization domain of p53 tumor suppressor. Biochemistry 34:5309-16
Freire, E (1995) Differential scanning calorimetry. Methods Mol Biol 40:191-218

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