Loading...
Please wait, while we are loading the content...
Similar Documents
Efficient Covalent Bond Formation in Gas-Phase Peptide–Peptide Ion Complexes with the Photoleucine Stapler
| Content Provider | Paperity |
|---|---|
| Author | Řezáč, Jan Andrikopoulos, Prokopis C. Shaffer, Christopher J. Rulíšek, Lubomír Tureček, František |
| Abstract | Noncovalent complexes of hydrophobic peptides GLLLG and GLLLK with photoleucine (L*) tagged peptides G(L* n L m )K (n = 1,3, m = 2,0) were generated as singly charged ions in the gas phase and probed by photodissociation at 355 nm. Carbene intermediates produced by photodissociative loss of N2 from the L* diazirine rings underwent insertion into X−H bonds of the target peptide moiety, forming covalent adducts with yields reaching 30%. Gas-phase sequencing of the covalent adducts revealed preferred bond formation at the C-terminal residue of the target peptide. Site-selective carbene insertion was achieved by placing the L* residue in different positions along the photopeptide chain, and the residues in the target peptide undergoing carbene insertion were identified by gas-phase ion sequencing that was aided by specific 13C labeling. Density functional theory calculations indicated that noncovalent binding to GL*L*L*K resulted in substantial changes of the (GLLLK + H)+ ground state conformation. The peptide moieties in [GL*L*LK + GLLLK + H]+ ion complexes were held together by hydrogen bonds, whereas dispersion interactions of the nonpolar groups were only secondary in ground-state 0 K structures. Born-Oppenheimer molecular dynamics for 100 ps trajectories of several different conformers at the 310 K laboratory temperature showed that noncovalent complexes developed multiple, residue-specific contacts between the diazirine carbons and GLLLK residues. The calculations pointed to the substantial fluidity of the nonpolar side chains in the complexes. Diazirine photochemistry in combination with Born-Oppenheimer molecular dynamics is a promising tool for investigations of peptide–peptide ion interactions in the gas phase. Open image in new window Graphical Abstract ᅟ |
| Starting Page | 633 |
| Ending Page | 645 |
| File Format | HTM / HTML |
| ISSN | 10440305 |
| DOI | 10.1007/s13361-016-1338-8 |
| Issue Number | 4 |
| Journal | Journal of The American Society for Mass Spectrometry |
| Volume Number | 27 |
| e-ISSN | 18791123 |
| Language | English |
| Publisher | Springer US |
| Publisher Date | 2016-01-27 |
| Access Restriction | Open |
| Subject Keyword | Laser photodissociation Peptide–peptide ion complexes Born-oppenheimer molecular dynamics Photoleucine Diazirine chromophores |
| Content Type | Text |
| Resource Type | Article |
| Subject | Spectroscopy Structural Biology |
