Isotopic Differentiation Protocol, a Selective Extraction of C- and N-Terminal Ions in ESI-Ms/Ms De Novo Peptide Sequencing
peer-reviewed · Natural Products Chemistry & Research · 2015
| Date | 2015-01-31 |
| Type | peer-reviewed |
| Venue | Natural Products Chemistry & Research |
| Publisher | OMICS Publishing Group |
| Contribution | adjacent |
| DOI | 10.4172/2329-6836.1000164 |
| Citations (OpenAlex) | 0 |
Abstract
Simple and selective extraction method of C- and N-terminal ions in ESI-MS/MS analyses, named isotopic differentiation protocol (IDP), was developed. It takes advantage of the mass-difference between the isotopologues after methyl and deuterated methyl ester formations at the C-terminal carboxylic acid or acetamide and deuterated acetamide formations at the N-terminal amines. This method distinguishes the N-terminal and C-terminal ions in principle to facilitate the de novo peptide sequencing. An application with non-ribosomal depsipeptide plipastatin revealed that a pair of the peptide and the corresponding methyl ester at the C-terminus was also applicable to IDP method giving spectrum with enough quality. Facilitating software named “MSMS Search Tool” was also developed.
Methods and tools
- Isotopic differentiation protocol (IDP): Forms light and deuterated methyl esters at the C-terminus or acetamides at the N-terminus so that mass shifts between isotopologues pick out C- and N-terminal ion series for de novo sequencing.