Characterization of a peptide family from the skin secretion of the Middle East Tree Frog Hyla savignyi by composition‐based de novo sequencing
peer-reviewed · Rapid Communications in Mass Spectrometry · 2010
| Date | 2010-10-15 |
| Type | peer-reviewed |
| Venue | Rapid Communications in Mass Spectrometry |
| Publisher | Wiley |
| Contribution | downstream-application |
| DOI | 10.1002/rcm.4717 |
| Citations (OpenAlex) | 13 |
| Venue 2-year citedness | 1.80 |
Abstract
A new tryptophyllin-like peptide family was found in the skin secretion of the tree frog Hyla savignyi. Peptides were characterized by database-independent sequencing strategies and specific ion fragmentation features were investigated. Skin secretions from specimens of Hyla savignyi were collected by mild electrical stimulation. Peptides were separated by reversed-phase nano-high-performance liquid chromatography (nanoHPLC) and mass spectra were acquired online by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS). Peptides were characterized by manual de novo sequencing and by composition-based sequencing (CBS), appearing mostly as C-terminal free acids and as their acid amide analogs. Amide peptides yielded lower intensities of y-type ions after collision-induced dissociation (CID) than their acid analogs. A mechanism of internal b-ion formation (positive ion mode) and of CO(2) elimination (negative ion mode) is proposed. We also exemplified phenomena such as the proline effect and formation of non-direct sequence ions after sequence rearrangements. The occurrence of rearrangement products, of internal ions and of the proline effect made the CID spectra highly complex. CBS analysis nevertheless resulted in successful and highly reliable sequence analysis.
Methods and tools
- Hyla savignyi tryptophyllin peptides: Spengler group characterized a tryptophyllin-like peptide family from the skin secretion of the Middle East tree frog by manual de novo and composition-based sequencing on FTICR-MS.
Methods it uses
- Composition-based sequencing: Two-step database-free strategy enabled by FT-ICR mass accuracy: determine the peptide’s amino acid COMPOSITION first, then score only the permutations that composition allows, which is a far smaller search space than conventional de novo sequencing explores.
- Manual MS/MS de novo interpretation: Protocol for manual de novo peptide sequencing from MS/MS spectra.