Heterogeneous platinum-catalyzed deuterium exchange of aromatic protons in amino acids, peptides and proteins

Abstract

In an attempt to simplify the proton magnetic resonance (PMR) spectra of proteins by exchange of amino acid side chain protons with deuterium, the platinum-catalyzed exchange of the aromatic protons of l-phenylalanine, a tripeptide containing phenylalanine and two proteins have been studied using PMR spectroscopy. Deuteration of the small model compounds proceed satisfactorily under mild conditions, but no exchange was observed of the aromatic protons of phenylalanyl or tyrosyl residues of native or denatured lysozyme or ribonuclease. Several possible explanations are suggested for this lack of exchange.