Synthesis of hydrophilic and flexible linkers for peptide derivatization in solid phase

Four N-Fmoc protected polyoxyethylene-based amino acid type linkers were designed and synthesized for peptide derivatization in solid phase. Three of them were obtained in a crystalline form. The crystallized linkers can be stored at 4 °C for 2 years without significant decomposition. Protocols for biotinylation and fluorescent labeling of peptides in solid phase were developed. The linkers also provide good ionization ability for single-bead mass spectrometry analysis of peptides.