A molecular design algorithm for peptide ligands has been developed. This design algorithm utilizes the structural parameterization of the energetics as a way of identifying the conformation with the minimum energy. The implementation of the algorithm involves two non-mutually exclusive procedures for computer mutagenesis of a lead peptide. Mutations in sequence by replacing side chains at existing positions in the peptide, and alteration of peptide chain length by addition or deletion of amino acids. Once the mutation is made it is necessary to sample the ensemble of possible conformations and evaluate the energy and corresponding probability of each conformation. The probability of a single peptide conformation, defined by a specific set of side chain and backbone coordinates, is dictated by a Gibbs energy function or Gibbs potential, Gef, specified by the enthalpy of intra and intermolecular peptide/protein interactions plus the enthalpy and entropy of solvation. Gef is a function of the side chain and backbone torsional angles. By definition, the conformational entropy of the peptide itself does not enter into the equation. Gef is the Gibbs energy function of a single conformation and should not be confused with the Gibbs energy of binding which includes all permissible conformations. The Gibbs potential function, Gef, is used to identify the most probable conformation of a side chain or backbone.

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
5P41RR004328-10
Application #
6122010
Study Section
Project Start
1997-08-05
Project End
1998-08-04
Budget Start
Budget End
Support Year
10
Fiscal Year
1997
Total Cost
Indirect Cost
Name
Johns Hopkins University
Department
Type
DUNS #
045911138
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Jaganaman, Sunil; Pinto, Alex; Tarasev, Michael et al. (2007) High levels of expression of the iron-sulfur proteins phthalate dioxygenase and phthalate dioxygenase reductase in Escherichia coli. Protein Expr Purif 52:273-9
Todd, M J; Gomez, J (2001) Enzyme kinetics determined using calorimetry: a general assay for enzyme activity? Anal Biochem 296:179-87
Karantza, V; Freire, E; Moudrianakis, E N (2001) Thermodynamic studies of the core histones: stability of the octamer subunits is not altered by removal of their terminal domains. Biochemistry 40:13114-23
Griko, Y V; Remeta, D P (1999) Energetics of solvent and ligand-induced conformational changes in alpha-lactalbumin. Protein Sci 8:554-61
Chu, V; Freitag, S; Le Trong, I et al. (1998) Thermodynamic and structural consequences of flexible loop deletion by circular permutation in the streptavidin-biotin system. Protein Sci 7:848-59
Luque, I; Freire, E (1998) Structure-based prediction of binding affinities and molecular design of peptide ligands. Methods Enzymol 295:100-27
Luque, I; Gomez, J; Semo, N et al. (1998) Structure-based thermodynamic design of peptide ligands: application to peptide inhibitors of the aspartic protease endothiapepsin. Proteins 30:74-85
Gomez, J; Semo, N; Freire, E (1998) Structural thermodynamic study of the binding of renin inhibitors to endothiapepsin. Adv Exp Med Biol 436:325-8
Koder, R L; Miller, A F (1998) Overexpression, isotopic labeling, and spectral characterization of Enterobacter cloacae nitroreductase. Protein Expr Purif 13:53-60
Freire, E (1998) Statistical thermodynamic linkage between conformational and binding equilibria. Adv Protein Chem 51:255-79

Showing the most recent 10 out of 86 publications