NEXAFS spectra and specific dissociation of oligo-peptide model molecules

Total-ion-yield near-edge X-ray absorption fine-structure (NEXAFS) spectra of three oligo-peptide model molecules were recorded. The NEXAFS spectra were also calculated with time-dependent density functional theory; the calculated spectra are consistent with the experimental measurements. The ionic...

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Bibliographic Details
Main Authors: Yu-Ju Chiang, Wan-Chou Huang, Chi-Kung Ni, Chen-Lin Liu, Cheng-Cheng Tsai, Wei-Ping Hu
Format: Article
Language:English
Published: AIP Publishing LLC 2019-08-01
Series:AIP Advances
Online Access:http://dx.doi.org/10.1063/1.5112151
Description
Summary:Total-ion-yield near-edge X-ray absorption fine-structure (NEXAFS) spectra of three oligo-peptide model molecules were recorded. The NEXAFS spectra were also calculated with time-dependent density functional theory; the calculated spectra are consistent with the experimental measurements. The ionic products from core-excited molecules and their branching ratios as functions of excitation energy show branching ratios 42%-75% of dissociation of the peptide bond, especially at resonant excitations. The major destination orbitals assigned at these excitation energies show significant antibonding character along peptide bonds, which causes large probabilities of bond cleavage.
ISSN:2158-3226