This proposal describes ongoing and future-planned investigations that seek to determine the role that net charge plays in biophysics-related problems.
The first aim presents the hypothesis that a protein's net charge plays a significant role in determining the rate of amide hydrogen exchange in proteins - a reaction that is catalyzed by hydroxide anion at pH>4. Protein charge ladders and mass spectrometry are used to test this charge-dependent exchange hypothesis.
The second aim of this proposal hypothesizes that protein aggregation, as related to many human diseases, can be inhibited with subtle chemical modifications that increase the protein's net charge. Controlling charge - as opposed to some other parameter or property such as native-state stability or structure - is an underemphasized and unexplored possibility in developing drug therapies for a wide array of diseases linked to protein aggregation. The experiments proposed in Aim 2 are intended as a proof of concept for this approach (termed PRO-CHAIN; PROtein CHarging for Aggregation INhibition).
Aim 3 proposes experiments to explore if electrostatic interactions between proteins and surfaces can be used to i) promote ii) direct iii) pattern, or iv) inhibit protein aggregation onto charge- micro-patterned self assembled monolayers (SAMs). The aggregation of proteins onto charged surfaces, such as lipid membranes, is gaining acceptance as a likely scenario in disease pathogenesis.
This third aim describes experiments using protein charge ladders, micro-contact printing and self assembled monolayers to explore this important phenomenon that is suspected to be relevant to a wide range of diseases. Relevance to public health: This proposal has immediate relevance to public health; first, it describes a whole new approach for developing drug therapies, referred to as PRO-CHAIN (PROtein CHarging for Aggregation INhibition), that may aid in the development therapies for the treatment of a wide range of protein aggregation diseases such as Alzheimer's disease and type II diabetes. Furthermore, this proposal describes research that may further our understanding of the molecular determinants of hydrogen exchange in protein folding studies -- many of these studies focus on pathogenic proteins that cause human disease. Lastly, this proposal uses new cutting edge technologies to study protein-surface interactions of the sort that may be related to numerous neurodegenerative diseases, as well as cancer. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32GM081055-02
Application #
7383891
Study Section
Special Emphasis Panel (ZRG1-F04B-N (20))
Program Officer
Flicker, Paula F
Project Start
2007-04-01
Project End
2009-03-31
Budget Start
2008-04-01
Budget End
2009-03-31
Support Year
2
Fiscal Year
2008
Total Cost
$49,646
Indirect Cost
Name
Harvard University
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
082359691
City
Cambridge
State
MA
Country
United States
Zip Code
02138
Shaw, Bryan F; Schneider, Gregory F; Whitesides, George M (2012) Effect of surfactant hydrophobicity on the pathway for unfolding of ubiquitin. J Am Chem Soc 134:18739-45
Shaw, Bryan F; Schneider, Gregory F; Arthanari, Haribabu et al. (2011) Complexes of native ubiquitin and dodecyl sulfate illustrate the nature of hydrophobic and electrostatic interactions in the binding of proteins and surfactants. J Am Chem Soc 133:17681-95
Shaw, Bryan F; Arthanari, Haribabu; Narovlyansky, Max et al. (2010) Neutralizing positive charges at the surface of a protein lowers its rate of amide hydrogen exchange without altering its structure or increasing its thermostability. J Am Chem Soc 132:17411-25
Kaufman, George K; Thomas, Samuel W; Reches, Meital et al. (2009) Phase separation of 2D meso-scale Coulombic crystals from meso-scale polarizable ""solvent"" Soft Matter 5:1188-1191
Shaw, Bryan F; Schneider, Gregory F; Bilgicer, Basar et al. (2008) Lysine acetylation can generate highly charged enzymes with increased resistance toward irreversible inactivation. Protein Sci 17:1446-55