Investigation of Intrinsically Disordered Proteins through Exchange with Hyperpolarized Water

Abstract

Hyperpolarized water can selectively enhance NMR signals of rapidly exchanging protons in osteopontin (OPN), a metastasis-associated intrinsically disordered protein (IDP), at near-physiological pH and temperature. The transfer of magnetization from hyperpolarized water is limited to solvent-exposed residues and therefore selectively enhances signals in ¹ H-¹⁵ N correlation spectra. Binding to the polysaccharide heparin was found to induce the unfolding of preformed structural elements in OPN.