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JPCL Cα-H Chirality Control N-H Chirality (20191119)-HFW20191124.pdf (1.19 MB)
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N–H Chirality in Folded Peptide LK7β is Governed by the Cα–H Chirality

preprint
submitted on 24.11.2019 and posted on 09.12.2019 by Xiaohua Hu, Li Fu, jian hou, yuening zhang, Zhen Zhang, Hongfei Wang
Recent chiral sum-frequency generation vibrational spectroscopy (cSFG-VS) measurements revealed that the two N-H stretching modes in the 3000-3500 cm-1 range in folded protein and peptide exhibit chiral characteristics. Here we report the first phase-resolved sub-wavenumber high-resolution broadband SFG-VS (HR-BB-SFG-VS) measurement of the LK7β peptide. The results show that this chiral N-H band consists of four, instead of two, distinctive peaks, and they are with two groups of opposite spectral phases. Moreover, the phases of these N-H peaks completely flip from the L-LK7β to the D-LK7β peptide, suggesting that the chirality of the N-H in the folded LK7β peptide is completely governed by the chirality of the Cα–H of the amino acids. This discovery provides clue on why proteins in nature are composed of α-amino acids rather than β- or γ-amino acids, and may help us understand the question on the origin of life.

History

Email Address of Submitting Author

wanghongfei@fudan.edu.cn

Institution

Fudan University

Country

China

ORCID For Submitting Author

0000-0001-8238-1641

Declaration of Conflict of Interest

No

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in The Journal of Physical Chemistry Letters

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