Gas-phase Sequencing of Photoimmobilized Peptides

Abstract

Aminopropylated glass-fiber discs were derivatized with the photosensitive reagents 3-(trifluoromethyl)-3-[m-(isothiocyano)phenyl]diazirine and p-azidophenyl isothiocyanate, respectively. Photolabel-derivatized solid supports were photo activated in the presence of a hexapeptide. Gas-phase sequence analysis of washed fiber discs yielded end-to-end sequences with photoactivated disks only, indicating efficient photo-immobilization of the applied peptide. The quantity of amino acid released with each Edman-de-gradation cycle conferred with the established philicity of amino-acid side chains for photogenerated carbenes. The procedure provides a hitherto unexplored way to immobilize biomolecules (polypeptides) through statistically occurring carbene or nitrene insertions.