Biomimicing behavior of amino acid-functionalized gold nanoparticles in enthalpy-entropy compensation

ORGN 607

Mrinmoy De, mrinmoy@chem.umass.edu1, Chang-Cheng You, cyou@chem.umass.edu1, and Vincent M. Rotello, rotello@chem.umass.edu2. (1) Department of Chemistry, University of Massachusetts at Amherst, 710 North Pleasant Street, Amherst, MA 01003, (2) Department of Chemistry, University of Massachusetts, 710 North Pleasant Street, Amherst, MA 01003
Recognition of protein surface by artificial receptors plays a key role in biomedical and biomaterial research. We have fabricated a series of water soluble L-amino acid-functionalized gold nanoparticles to target &alpha-chymotrypsin. Isothermal titration calorimetric studies were conducted to evaluate the thermodynamic origin of complex formation. The result shows that the binding process is predominantly controlled by the enthalpic contributions, along with an unfavorable entropy change. By varying the ionic strength, the thermodynamic contribution of these two factors could be reversed. Furthermore entropy-enthalpy compensation analysis was performed to assess the binding thermodynamics of nanoparticles with various proteins, revealing that the complex formation experiences large conformational changes and extensive dissolvation. These features strongly resemble the natural protein-protein interaction.
 

Molecular Recognition and Self-Assembly
1:00 PM-5:00 PM, Wednesday, March 28, 2007 McCormick Place Lakeside -- Room E352, Level 3, Oral

Division of Organic Chemistry

The 233rd ACS National Meeting, Chicago, IL, March 25-29, 2007