Structural Analysis of 14-3-3-ζ-Derived Phosphopeptides Using Electron Capture Dissociation Mass Spectrometry, Traveling Wave Ion Mobility Spectrometry, and Molecular Modeling
Autor: | Iain B. Styles, Helen J. Cooper, David H. Russell, Anna L. Simmonds, Andrea F. Lopez-Clavijo, Peter J. Winn |
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Rok vydání: | 2019 |
Předmět: |
Models
Molecular Phosphopeptides Molecular model Ion-mobility spectrometry Amino Acid Motifs 010402 general chemistry Mass spectrometry 01 natural sciences Mass Spectrometry Article Fragmentation (mass spectrometry) 0103 physical sciences Ion Mobility Spectrometry Materials Chemistry Non-covalent interactions Amino Acid Sequence Physical and Theoretical Chemistry Peptide sequence chemistry.chemical_classification 010304 chemical physics Electron-capture dissociation Phosphopeptide Chemistry Peptide Fragments 0104 chemical sciences Surfaces Coatings and Films Crystallography 14-3-3 Proteins |
Zdroj: | J Phys Chem B |
ISSN: | 1520-5207 |
Popis: | Previously, we have demonstrated the effect of salt bridges on the electron capture dissociation mass spectrometry behavior of synthetic model phosphopeptides and applied an ion mobility spectrometry/molecular modeling approach to rationalize the findings in terms of peptide ion structure. Here, we develop and apply the approach to a biologically derived phosphopeptide. Specifically, we have investigated variants of a 15-mer phosphopeptide VVGARRSsWRVVSSI (s denotes phosphorylated Ser) derived from Akt1 substrate 14-3-3-ζ, which contains the phosphorylation motif RRSsWR. Variants were generated by successive arginine-to-leucine substitutions within the phosphorylation motif. ECD fragmentation patterns for the eight phosphopeptide variants show greater sequence coverage with successive R → L substitutions. Peptides with two or more basic residues had regions with no sequence coverage, while full sequence coverage was observed for peptides with one or no basic residues. For three of the peptide variants, low-abundance fragments were observed between the phosphoserine and a basic residue, possibly due to the presence of multiple conformers with and without noncovalent interactions between these residues. For the five variants whose dissociation behavior suggested the presence of intramolecular noncovalent interactions, we employed ion mobility spectrometry and molecular modeling to probe the nature of these interactions. Our workflow allowed us to propose candidate structures whose noncovalent interactions were consistent with the ECD data for all of the peptides modeled. Additionally, the AMBER parameter sets created for and validated by this work are presented and made available online ( http://www.biosciences-labs.bham.ac.uk/cooper/datasets.php ). |
Databáze: | OpenAIRE |
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