Universität zu Köln

Wang, Ran, Yang, Bo, Wu, R. R., Rodgers, M. T., Schaefer, M. and Armentrout, P. B. (2015). Guided Ion Beam and Computational Studies of the Decomposition of a Model Thiourea Protein Cross-Linker. J. Phys. Chem. B, 119 (9). S. 3727 - 3743. WASHINGTON: AMER CHEMICAL SOC. ISSN 1520-6106

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Abstract

The dissociation of protonated methyl-d(3) thiourea-4-butyric acid methyl amide (<bold>1</bold>), a model of thiourea-based protein cross-linking compounds, is examined both experimentally and computationally. Using a guided ion beam tandem mass spectrometer (GIBMS), the threshold collision-induced dissociation (TCID) of [<bold>1</bold> + H](+) with Xe is examined as a function of collision energy. Analysis of the kinetic energy-dependent CID cross sections provides the 0 K barriers for four primary and four secondary dissociation pathways, after accounting for competition between channels, sequential dissociations, unimolecular decay rates, internal energy of reactant ions, and multiple ion-neutral collisions. Computations are used to explore the pathways for the various processes and elucidation of their rate-limiting transition states. These results indicate that dissociation is initiated by migration of the excess proton from sulfur to one of three nitrogen atoms in <bold>1</bold>, similar to the mobile proton model of peptide fragmentation. The computational energies for the rate-limiting transition states are generally in good agreement with the experimentally derived threshold energies, with MP2(full)/6-311+G(2d,2p)//B3LYP/6-311+G(d,p) results being particularly favorable. This good comparison validates the mechanisms explored theoretically and allows identification of the structures of the various product ions and neutrals.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Wang, Ran UNSPECIFIED UNSPECIFIED UNSPECIFIED Yang, Bo UNSPECIFIED UNSPECIFIED UNSPECIFIED Wu, R. R. UNSPECIFIED UNSPECIFIED UNSPECIFIED Rodgers, M. T. UNSPECIFIED UNSPECIFIED UNSPECIFIED Schaefer, M. UNSPECIFIED UNSPECIFIED UNSPECIFIED Armentrout, P. B. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-405138
DOI:	10.1021/jp512997z
Journal or Publication Title:	J. Phys. Chem. B
Volume:	119
Number:	9
Page Range:	S. 3727 - 3743
Date:	2015
Publisher:	AMER CHEMICAL SOC
Place of Publication:	WASHINGTON
ISSN:	1520-6106
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language COLLISION-INDUCED DISSOCIATION; MASS-SPECTROMETRIC ANALYSIS; STRUCTURAL PROTEOMICS; KINETIC SHIFTS; AMINO-ACIDS; MOLECULAR RECOGNITION; CATION DISSOCIATION; BINDING-ENERGIES; BOND-ENERGIES; BASIS-SETS Multiple languages Chemistry, Physical Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/40513