Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry of model prebiotic peptides: Optimization of sample preparation

Abstract

Understanding the diversity and chemical evolution of proto-peptides is of interest to origins-of-life research. Here, we have demonstrated MALDI-TOF mass spectrometry can be used to rapidly screen the length and monomer composition of model prebiotic peptides containing a mixture of ester and amide backbone linkages.

Proline Behavior in Model Prebiotic Peptides Formed by Wet–Dry Cycling

“…The longest depsipeptide observed in these experiments had 19 residues (17a + 2V; MALDI Appendix, Supporting Information), and the longest depsipeptides with >50% amino acid content had 18 residues (7g + 11G and 8g + 10G; MALDI Appendix, Supporting Information). In a previous manuscript, we detected a depsipeptide with 21 residues . After 12 cycles, elongation was stunted, likely due to monomer consumption.…”

“…In a previous manuscript, we detected a depsipeptide with 21 residues. 50 After 12 cycles, elongation was stunted, likely due to monomer consumption. Continued seeding of amino acids during cycling can extend chains, 13,62 but this was not the emphasis of our study.…”

“…Our group previously optimized this sample preparation in order to maximize depsipeptide signal and minimize matrix background. 50 The TOF was calibrated daily, and it showed a typical resolving power of ∼5000 m/Δm fwhm. TOF mass errors were less than ±0.…”

“…Plates were dried with a gentle flow of air at room temperature and pressure. Our group previously optimized this sample preparation in order to maximize depsipeptide signal and minimize matrix background . The TOF was calibrated daily, and it showed a typical resolving power of ∼5000 m /Δ m fwhm.…”

Qualitative Monitoring of Proto-Peptide Condensation by Differential FTIR Spectroscopy

“…MS data were obtained on a refurbished Voyager DE-STR (JBI Scientific) matrix-assisted laser desorption/ionization–time-of-flight (MALDI-TOF) instrument equipped with a 337 nm nitrogen gas laser fired at 20 Hz . All spectra were acquired in positive-ion, reflector TOF mode.…”