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Infrared Probing of 4-Azidoproline Conformations Modulated by Azido Configurations.

Authors :
Lee, Kyung-Koo
Park, Kwang-Hee
Joo, Cheonik
Kwon, Hyeok-Jun
Jeon, Jonggu
Jung, Hyeon-Il
Park, Sungnam
Han, Hogyu
Cho, Minhaeng
Source :
Journal of Physical Chemistry B. May2012, Vol. 116 Issue 17, p5097-5110. 14p.
Publication Year :
2012

Abstract

4-Azidoproline (Azp) can tune the stability of the polyproline II (PII) conformation in collagen. The azido group in the 4Rand 4Sconfigurations stabilizes and destabilizes the PIIconformation, respectively. To obtain insights into the dependence of the conformational stability on the azido configuration, we carried out Fourier transform (FT) IR experiments with four 4-azidoproline derivatives, Ac-(4R/S)-Azp-(NH/O)Me. We found that the amide I and azido IR spectra are different depending on the azido configuration and C-terminal structure. The origin of such spectral differences between 4Rand 4Sconfigurations and between C-terminal methylamide and ester ends was elucidated by quantum chemistry calculations in combination with 1H NMR and time- and frequency-resolved IR pump–probe spectroscopy. We found that the azido configurations and C-terminal structures affect intramolecular interactions, which are responsible for the ensuing conformational and thereby IR spectral differences. Consequently, 4-azidoproline conformations modulated by azido configurations can be probed by IR spectroscopy. These findings suggest that 4-azidoproline can be both a structure-control and -probing element, which enables the infrared tracking of proline roles in protein structure, function, and dynamics. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
15206106
Volume :
116
Issue :
17
Database :
Academic Search Index
Journal :
Journal of Physical Chemistry B
Publication Type :
Academic Journal
Accession number :
80744291
Full Text :
https://doi.org/10.1021/jp1085119