We will continue to refine and extend UV resonance Raman spectroscopy (UVRR) as a sensitive, incisive technique for examining amide excited states, bio-molecular structure and function, and folding dynamics. We will use UVRR to examine the most important phenomena in protein folding such as the evolution of secondary structure and hydrophobic collapse. 1) We will use our recently discovered correlation between the amide III Raman band frequency and the Ramachandran Y angle to experimentally map the energy landscapes of proteins and peptides. We will use the T-jump UVRR methods pioneered in our lab to explore the peptide conformational dynamics that occur along the (un)folding reaction coordinates. We will measure, for the first time, the relative energies of protein conformational motifs and of their surface crossing conformational activation barriers. We will examine the evolution of secondary structure in response to temperature and solution environment alterations. 2) We will also examine cold denaturation in well defined nanogels of the homopolymer poly-N-isopropylacrylamide, which undergoes a temperature-driven volume phase transition similar to the cold denaturation phenomenon of proteins. We will utilize the understanding gained in these studies to explore the dramatic cold denaturation process in elastin, a biologically essential protein. Elastin's extensive cold denaturation process appears to be a consequence of its unique structure, which enables it to change volume without storage of the elastic energy that could lead to bond breakage. We will examine the coupling between elastin's hydrophobic collapse and its secondary structural evolution. 3) We will continue to develop and refine UV Raman instrumentation and methodologies to make this powerful spectroscopic technique more sensitive, more incisive and less expensive for use in biophysical and bio-analytical investigations. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Type
Research Project (R01)
Project #
5R01EB002053-26
Application #
7467386
Study Section
Macromolecular Structure and Function B Study Section (MSFB)
Program Officer
Zhang, Yantian
Project Start
1982-06-01
Project End
2010-07-31
Budget Start
2008-08-01
Budget End
2010-07-31
Support Year
26
Fiscal Year
2008
Total Cost
$339,064
Indirect Cost
Name
University of Pittsburgh
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
004514360
City
Pittsburgh
State
PA
Country
United States
Zip Code
15213
Hong, Zhenmin; Wert, Jonathan; Asher, Sanford A (2013) UV resonance Raman and DFT studies of arginine side chains in peptides: insights into arginine hydration. J Phys Chem B 117:7145-56
Zhang, Jian-Tao; Chao, Xing; Asher, Sanford A (2013) Asymmetric free-standing 2-D photonic crystal films and their Janus particles. J Am Chem Soc 135:11397-401
Hong, Zhenmin; Ahmed, Zeeshan; Asher, Sanford A (2011) Circular dichroism and ultraviolet resonance Raman indicate little Arg-Glu side chain ?-helix peptide stabilization. J Phys Chem B 115:4234-43
Bykov, Sergei V; Asher, Sanford A (2010) UV Resonance Raman Elucidation of the Terminal and Internal Peptide Bond Conformations of Crystalline and Solution Oligoglycines. J Phys Chem Lett 1:269-271
Bykov, Sergei; Asher, Sanford (2010) Raman studies of solution polyglycine conformations. J Phys Chem B 114:6636-41
Asciutto, Eliana K; General, Ignacio J; Xiong, Kan et al. (2010) Sodium perchlorate effects on the helical stability of a mainly alanine peptide. Biophys J 98:186-96
Xiong, Kan; Asher, Sanford A (2010) Circular dichroism and UV resonance raman study of the impact of alcohols on the Gibbs free energy landscape of an alpha-helical peptide. Biochemistry 49:3336-42
Sharma, Bhavya; Asher, Sanford A (2010) UV resonance Raman investigation of the conformations and lowest energy allowed electronic excited states of tri- and tetraalanine: charge transfer transitions. J Phys Chem B 114:6661-8
Ahmed, Zeeshan; Gooding, Edward A; Pimenov, Konstantin V et al. (2009) UV resonance Raman determination of molecular mechanism of poly(N-isopropylacrylamide) volume phase transition. J Phys Chem B 113:4248-56
Ahmed, Zeeshan; Scaffidi, Jonathan P; Asher, Sanford A (2009) Circular dichroism and UV-resonance Raman investigation of the temperature dependence of the conformations of linear and cyclic elastin. Biopolymers 91:52-60

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