Please use this identifier to cite or link to this item:
|Title:||The role of metal cation in electron-induced dissociation of tryptophan|
|Source:||Feketeová, L., Wong, M.W., O'Hair, R.A.J. (2010-10). The role of metal cation in electron-induced dissociation of tryptophan. European Physical Journal D 60 (1) : 11-20. ScholarBank@NUS Repository. https://doi.org/epjd/e2010-00019-6|
|Abstract:||The fragmentation of tryptophan (Trp) - metal complexes [Trp+M] +, where M = Cs, K, Na, Li and Ag, induced by 22 eV energy electrons was compared to [Trp+H]+. Additional insights were obtained through the study of collision-induced dissociation (CID) of [Trp+M]+ and through deuterium labelling. The electron-induced dissociation (EID) of [Trp+M]+ resulted in the formation of radical cations via the following pathways: (i) loss of M to form Trp+•, (ii) loss of an H atom to form [(Trp-H)+M]+•, and (iii) bond homolysis to form C2H4NO2M+•. Deuterium labelling suggests that H atom loss can occur from heteroatom and/or C-H positions. Other types of fragment ions observed include: C9H7NM +, C9H8N+, M+, C 2H3NO2M+, CO2M +, C10H11N2M+, C 10H9NOM+. Formation of C2H 4NO2M+• and C9H 7NM+ cations suggests that the metal interacts with both the backbone and aromatic side chain, thus implicating π-interactions for all M. CID of [Trp+M]+ resulted in: loss of metal cation (for M = Cs and K); successive loss of NH3 and CO as the dominant channel for M = Na, Li and Ag; formation of C2H3NO2M +. Preliminary DFT calculations were carried out on [Trp+Na] + and [(Trp-H)+Na]+• which reveal that: the most stable conformation involves chelation by the backbone together with a π -interaction with the indole side chain; loss of H atom from α -CH of the side chain is thermodynamically favoured over losses from other positions, with the resultant radical cation maintaining a (N, O, ring) chelated structure which is stabilized by conjugation. © 2010 EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg.|
|Source Title:||European Physical Journal D|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
WEB OF SCIENCETM
checked on Jan 31, 2018
checked on Feb 12, 2018
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.