Measurement of the coil-to-helix transition in poly-L-glutamic acid via temperature derivative spectroscopy

PHYS 382

Michael Gregory, mgregory@islander.tamucc.edu, Mathew Anderson, mathewanderson_3@yahoo.com, Melissa Griffith, and Timothy P. Causgrove, tim.causgrove@tamucc.edu. Physical & Environmental Sciences, Texas A&M University-Corpus Christi, 6300 Ocean Drive, Unit 5802, Corpus Christi, TX 78412-5802
The activation energy for helix formation in poly-L-glutamic acid (polyGlu) was measured at cryogenic temperatures in D2O/glycerol solution. Protonation of polyGlu side chains was accomplished using UV-induced photolysis of o-nitrobenzaldehyde to form o-nitrosobenzoic acid at 150 K. The temperature was then raised to 225 K while monitoring the amide I' region to detect helix formation. The temperature range of amide I' absorption changes is related to the distribution of activation energies required for helix formation. The dependence of the activation energy for the coil-to-helix transition on initial helix content is discussed.
 

PHYS Poster Session - General Experiment
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster

Division of Physical Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008