Gas-phase hydrogen/deuterium exchange as a molecular probe for the interaction of methanol and protonated peptides

✍ Scribed by Eric Gard; M.Kirk Green; Jennifer Bregar; Carlito B. Lebrilla

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 926 KB
• Volume: 5
• Category: Article
• ISSN: 1044-0305
• DOI: 10.1016/1044-0305(94)85003-8

✦ Synopsis

The gas-phase hydrogen/deuterium (HID) exchange kinetics of several protonated amino acids and dipeptides under a background pressure of CH3OD were determined in an external source Fourier transform mass spectrometer. H/D exchange reactions occur even when the gas-phase basicity of the compound is significantly larger (> 20 kcal/mol) than methanol. In addition; greater deuterium incorporation is observed for compounds that have multiple sites of similar basicities. A mechanism is proposed that involves a structurally specific intermediate with extensive interaction between the protonated compound and methanol.