Transnitrosylation products of the dipeptide cysteinyl-cysteine: An examination by tandem mass spectrometry and density functional theory
The fragmentation pathways of protonated mono-and di-nitrosylated derivatives from the dipeptide Cys-Cys obtained by electrospray were examined. Protonated mononitrosylated dipeptide upon loss of NO formed a radical cation, which in turn shows two fragment ions, one from the loss of HS and the other...
Guardado en:
| Autores principales: | , , |
|---|---|
| Formato: | JOUR |
| Materias: | |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_14639076_v18_n8_p6047_Butler |
| Aporte de: |
| id |
todo:paper_14639076_v18_n8_p6047_Butler |
|---|---|
| record_format |
dspace |
| spelling |
todo:paper_14639076_v18_n8_p6047_Butler2023-10-03T16:16:54Z Transnitrosylation products of the dipeptide cysteinyl-cysteine: An examination by tandem mass spectrometry and density functional theory Butler, M. Michael Siu, K.W. Hopkinson, A.C. cysteine cysteinylcysteine dipeptide chemistry electrospray mass spectrometry tandem mass spectrometry thermodynamics Cysteine Dipeptides Spectrometry, Mass, Electrospray Ionization Tandem Mass Spectrometry Thermodynamics The fragmentation pathways of protonated mono-and di-nitrosylated derivatives from the dipeptide Cys-Cys obtained by electrospray were examined. Protonated mononitrosylated dipeptide upon loss of NO formed a radical cation, which in turn shows two fragment ions, one from the loss of HS and the other from a neutral loss giving a radical cation of formula C2H5NS+. Protonated dinitrosylated dipeptide dissociated by losing both NO molecules, forming a cyclic structure with a vicinal disulfide bridge whose major dissociation channel was the loss of CO. After CO loss, two pathways were observed (loss of NH3 and C2H3NS) which were preceded by proton exchange occurring between one β-carbon and the nitrogen atom. DFT calculations did not show significant differences in the energies involved for the loss of the NO radical from either of the cysteine residues of the protonated di-nitrosylated dipeptide. Upon loss of the first NO radical, the thiyl radical afforded the vicinal disulfide product with a small barrier through radical substitution of the remaining NO moiety. The calculated relative energy barriers for the different channels are in good agreement with experimental observations. Structures of the ions obtained after dissociation are suggested on the basis of the proposed mechanisms. © 2016 the Owner Societies. Fil:Butler, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_14639076_v18_n8_p6047_Butler |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
cysteine cysteinylcysteine dipeptide chemistry electrospray mass spectrometry tandem mass spectrometry thermodynamics Cysteine Dipeptides Spectrometry, Mass, Electrospray Ionization Tandem Mass Spectrometry Thermodynamics |
| spellingShingle |
cysteine cysteinylcysteine dipeptide chemistry electrospray mass spectrometry tandem mass spectrometry thermodynamics Cysteine Dipeptides Spectrometry, Mass, Electrospray Ionization Tandem Mass Spectrometry Thermodynamics Butler, M. Michael Siu, K.W. Hopkinson, A.C. Transnitrosylation products of the dipeptide cysteinyl-cysteine: An examination by tandem mass spectrometry and density functional theory |
| topic_facet |
cysteine cysteinylcysteine dipeptide chemistry electrospray mass spectrometry tandem mass spectrometry thermodynamics Cysteine Dipeptides Spectrometry, Mass, Electrospray Ionization Tandem Mass Spectrometry Thermodynamics |
| description |
The fragmentation pathways of protonated mono-and di-nitrosylated derivatives from the dipeptide Cys-Cys obtained by electrospray were examined. Protonated mononitrosylated dipeptide upon loss of NO formed a radical cation, which in turn shows two fragment ions, one from the loss of HS and the other from a neutral loss giving a radical cation of formula C2H5NS+. Protonated dinitrosylated dipeptide dissociated by losing both NO molecules, forming a cyclic structure with a vicinal disulfide bridge whose major dissociation channel was the loss of CO. After CO loss, two pathways were observed (loss of NH3 and C2H3NS) which were preceded by proton exchange occurring between one β-carbon and the nitrogen atom. DFT calculations did not show significant differences in the energies involved for the loss of the NO radical from either of the cysteine residues of the protonated di-nitrosylated dipeptide. Upon loss of the first NO radical, the thiyl radical afforded the vicinal disulfide product with a small barrier through radical substitution of the remaining NO moiety. The calculated relative energy barriers for the different channels are in good agreement with experimental observations. Structures of the ions obtained after dissociation are suggested on the basis of the proposed mechanisms. © 2016 the Owner Societies. |
| format |
JOUR |
| author |
Butler, M. Michael Siu, K.W. Hopkinson, A.C. |
| author_facet |
Butler, M. Michael Siu, K.W. Hopkinson, A.C. |
| author_sort |
Butler, M. |
| title |
Transnitrosylation products of the dipeptide cysteinyl-cysteine: An examination by tandem mass spectrometry and density functional theory |
| title_short |
Transnitrosylation products of the dipeptide cysteinyl-cysteine: An examination by tandem mass spectrometry and density functional theory |
| title_full |
Transnitrosylation products of the dipeptide cysteinyl-cysteine: An examination by tandem mass spectrometry and density functional theory |
| title_fullStr |
Transnitrosylation products of the dipeptide cysteinyl-cysteine: An examination by tandem mass spectrometry and density functional theory |
| title_full_unstemmed |
Transnitrosylation products of the dipeptide cysteinyl-cysteine: An examination by tandem mass spectrometry and density functional theory |
| title_sort |
transnitrosylation products of the dipeptide cysteinyl-cysteine: an examination by tandem mass spectrometry and density functional theory |
| url |
http://hdl.handle.net/20.500.12110/paper_14639076_v18_n8_p6047_Butler |
| work_keys_str_mv |
AT butlerm transnitrosylationproductsofthedipeptidecysteinylcysteineanexaminationbytandemmassspectrometryanddensityfunctionaltheory AT michaelsiukw transnitrosylationproductsofthedipeptidecysteinylcysteineanexaminationbytandemmassspectrometryanddensityfunctionaltheory AT hopkinsonac transnitrosylationproductsofthedipeptidecysteinylcysteineanexaminationbytandemmassspectrometryanddensityfunctionaltheory |
| _version_ |
1807314428139405312 |