Approximately one third of all protein bind metal ions.Such metalloproteins play crucial roles in a large number of biological processes including the storage and transduction of energy, gene regulation, and metabolism. In order for these proteins to achieve their proper functions, they must selectively bind their cognate metal ions. Such recognition processes have been generally assumed to be governed by simple, thermodynamically controlled, binding reactions. Evidence has been accumulating revealing the importance of kinetic factors as well. The kinetics of metal binding and exchange reactions have not been extensively studied. The thermodynamics and kinetics of metal binding reactions appear to be significantly affected by the degree of structure that remains in the protein upon removal of the metal ion. The thermodynamics and kinetics of metal binding, release, and exchange reactions will be studied for a series of protein that differ in terms of these structural characteristics. Systems for which protein folding is induced only upon metal binding offer unique opportunities for investigating both metal binding and protein folding processes. Such studies will be performed with the use of a so- called zinc finger peptide. Aspects of protein folding to be investigated include the thermodynamic propensities for different amino acids to adopt beta sheet, alpha helix, and other structures. The data obtained will be interpreted in terms of a structure-based thermodynamics analysis model that has been developed for studies of other protein folding and binding reactions. Finally, the ability to modulate metal binding affinity through variations in protein folding energies will be utilized to generate a series of peptide sensors to be used to monitor zinc and other metal ion concentrations via changes in fluorescence.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Program Projects (P01)
Project #
5P01GM051362-03
Application #
6271815
Study Section
Project Start
1998-06-01
Project End
1999-05-31
Budget Start
1997-10-01
Budget End
1998-09-30
Support Year
3
Fiscal Year
1998
Total Cost
Indirect Cost
Name
Johns Hopkins University
Department
Type
DUNS #
045911138
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Maynard, Ernest L; Berg, Jeremy M (2007) Quantitative analysis of peroxisomal targeting signal type-1 binding to wild-type and pathogenic mutants of Pex5p supports an affinity threshold for peroxisomal protein targeting. J Mol Biol 368:1259-66
Amzel, L Mario; Siebert, Xavier; Armstrong, Anthony et al. (2005) Thermodynamic calculations in biological systems. Biophys Chem 117:239-54
Siebert, Xavier; Amzel, L Mario (2004) Loss of translational entropy in molecular associations. Proteins 54:104-15
Gatto Jr, Gregory J; Maynard, Ernest L; Guerrerio, Anthony L et al. (2003) Correlating structure and affinity for PEX5:PTS1 complexes. Biochemistry 42:1660-6
Kang, Lin-Woo; Gabelli, Sandra B; Bianchet, Mario A et al. (2003) Structure of a coenzyme A pyrophosphatase from Deinococcus radiodurans: a member of the Nudix family. J Bacteriol 185:4110-8
Ahmed, Hafiz; Bianchet, Mario A; Amzel, L Mario et al. (2002) Novel carbohydrate specificity of the 16-kDa galectin from Caenorhabditis elegans: binding to blood group precursor oligosaccharides (type 1, type 2, Talpha, and Tbeta) and gangliosides. Glycobiology 12:451-61
Nezami, Azin; Luque, Irene; Kimura, Tooru et al. (2002) Identification and characterization of allophenylnorstatine-based inhibitors of plasmepsin II, an antimalarial target. Biochemistry 41:2273-80
Luque, Irene; Leavitt, Stephanie A; Freire, Ernesto (2002) The linkage between protein folding and functional cooperativity: two sides of the same coin? Annu Rev Biophys Biomol Struct 31:235-56
Velazquez-Campoy, A; Kiso, Y; Freire, E (2001) The binding energetics of first- and second-generation HIV-1 protease inhibitors: implications for drug design. Arch Biochem Biophys 390:169-75
Velazquez-Campoy, A; Todd, M J; Vega, S et al. (2001) Catalytic efficiency and vitality of HIV-1 proteases from African viral subtypes. Proc Natl Acad Sci U S A 98:6062-7

Showing the most recent 10 out of 39 publications