Related Experiment Video
Updated: Apr 28, 2026

Characterization of MLKL-mediated Plasma Membrane Rupture in Necroptosis
Published on: August 7, 2018
Selectivity in fragmentation of N-methylacetamide after resonant K-shell excitation
Peter Salén1, Magdalena Kamińska, Richard J Squibb
1Department of Physics, Stockholm University, 106 91 Stockholm, Sweden.
Abstract:
The fragmentation pattern of the peptide model system, N-methylacetamide, is investigated using ion time-of-flight (TOF) spectroscopy after resonant K-shell excitation. Corresponding near-edge X-ray absorption fine structure (NEXAFS) spectra recorded at high resolution at the C1s, N1s and O1s edges are presented. Analysis of the ion TOF data reveals a multitude of fragmentation channels and dissociation pathways. Comparison between the excitation of six different resonances in the vicinity of the C1s, N1s and O1s edges suggests evidence for site-selective bond breaking. In particular the breaking of the peptide bond and the N-C(α) bond show a clear correlation with resonant excitation at the N1s edge. Also, stronger tendencies towards site-selective bond breaking are found for the generation of single ions compared with ion pairs. Analysis of angular distributions of ions from breakage of the peptide bond yields a fragmentation time of <400 fs.
Related Concept Videos
Mass Spectrometry: Carboxylic Acid, Ester, and Amide Fragmentation
For example,...
Mass Spectrometry: Long-Chain Alkane Fragmentation
Mass Spectrometry: Aldehyde and Ketone Fragmentation
¹H NMR: Complex Splitting
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied...
Mass Spectrometry: Molecular Fragmentation Overview
One type of fragmentation pattern is the cleavage of a single bond in the molecular ion. The cleavage leads to a radical and a cation. The cleavage can occur at...
Mass Spectrometry: Amine Fragmentation
In amines, the number of nitrogen atoms affects the mass of the molecular ion, which is described by the nitrogen rule of mass spectrometry. This rule states that a compound containing...

