TY  - JOUR
ID  - pittir17221
UR  - http://d-scholarship-dev.library.pitt.edu/17221/
IS  - 26
A1  - Lu, M
A1  - Ahmed, Z
A1  - Mikhonin, AV
A1  - Asher, SA
Y1  - 2007/07/05/
N2  - UV resonance Raman spectroscopy has been used to determine the conformational energy landscape of polyL-lysine (PLL) in the presence of NaClO4 as a function of temperature. At 1 °C, in the presence of 0.83 M NaClO4, PLL shows an ?86% ?-helix-like content, which contains ?-helix and ?-bulge/helix conformations. The high a-helix-like content of PLL occurs because of charge screening due to strong ion-pair formation between ClO4- and the lysine side chain -NH3+. As the temperature increases from 1 to 60 °C, the ?-helix and ?-bulge/helix conformations melt into extended conformations (PPII and 2.51-helix). We calculate the ? Ramachandran angle distribution of the PLL peptide bonds from the UV Raman spectra which allows us to calculate the PLL (un)folding energy landscapes along the ? reaction coordinate. We observe a basin in the ? angle conformational space associated with ?-helix and ?-bulge/helix conformations and another basin for the extended PPII and 2.5 1-helical conformations. © 2007 American Chemical Society.
JF  - Journal of Physical Chemistry B
VL  - 111
SN  - 1520-6106
TI  - UV resonance raman measurements of poly-L-lysine's conformational energy landscapes: Dependence on perchlorate concentration and temperature
SP  - 7675 
AV  - public
EP  -  7680
ER  -