scholarly journals Supplemental Activation Method for High-Efficiency Electron-Transfer Dissociation of Doubly Protonated Peptide Precursors

2007 ◽  
Vol 79 (2) ◽  
pp. 477-485 ◽  
Author(s):  
Danielle L. Swaney ◽  
Graeme C. McAlister ◽  
Matthew Wirtala ◽  
Jae C. Schwartz ◽  
John E. P. Syka ◽  
...  
2017 ◽  
Vol 23 (6) ◽  
pp. 376-384 ◽  
Author(s):  
Sergey V Kovalyov ◽  
Sergey S Zhokhov ◽  
Ludmila V Onoprienko ◽  
Boris V Vaskovsky ◽  
Albert T Lebedev

Electron-transfer dissociation (ETD) and electron-transfer and higher-energy collision dissociation (EThcD) spectra of short tryptic peptides with leucine/isoleucine residues in neighboring positions demonstrate intensive w-ions. On the contrary, u-ions possess very low intensities (if present at all). Therefore radical site migration is negligible in the applied conditions while ETD (EThcD) spectra allow for the reliable discrimination of the isomeric residues in the sequencing process. The presence of a fragment ion 43.055 mass units lower than z2-ion of peptides with IK sequence at their C-termini was shown to be a result of alternative fragmentation starting from the loss of propylammonium ion from the doubly protonated peptide molecule and formation of an oxazole fragment ion.


2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Miao Guo ◽  
Xiangtao Kong ◽  
Chunzhi Li ◽  
Qihua Yang

AbstractHydrogenation of benzoic acid (BA) to cyclohexanecarboxylic acid (CCA) has important industrial and academic significance, however, the electron deficient aromatic ring and catalyst poisoning by carboxyl groups make BA hydrogenation a challenging transformation. Herein, we report that Pt/TiO2 is very effective for BA hydrogenation with, to our knowledge, a record TOF of 4490 h−1 at 80 °C and 50 bar H2, one order higher than previously reported results. Pt/TiO2 catalysts with electron-deficient and electron-enriched Pt sites are obtained by modifying the electron transfer direction between Pt and TiO2. Electron-deficient Pt sites interact with BA more strongly than electron-rich Pt sites, helping the dissociated H of the carboxyl group to participate in BA hydrogenation, thus enhancing its activity. The wide substrate scope, including bi- and tri-benzoic acids, further demonstrates the high efficiency of Pt/TiO2 for hydrogenation of BA derivatives.


2007 ◽  
Vol 21 (5) ◽  
pp. 661-666 ◽  
Author(s):  
Qibin Zhang ◽  
Andrej Frolov ◽  
Ning Tang ◽  
Ralf Hoffmann ◽  
Tom van de Goor ◽  
...  

PROTEOMICS ◽  
2010 ◽  
Vol 10 (6) ◽  
pp. 1190-1195 ◽  
Author(s):  
Eric W. Deutsch ◽  
David Shteynberg ◽  
Henry Lam ◽  
Zhi Sun ◽  
Jimmy K. Eng ◽  
...  

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