Biomolecular phase transitions by non-equilibrium NMR and dissolution DNP

Prof. Dr. Dennis Kurzbach, University of Vienna (Austria)

Contemporarily, the physical chemistry of phase transitions witnesses a lively renaissance in a novel, biomolecular context. The functional importance of such conversion has become increasingly evident, e.g., in liquid-liquid phase separation (LLPS) of intrinsically disordered proteins and biomineral precursors. To characterize and understand these complex events, new experimental methods are necessary to shed light on the atomistic configuration of biomacromolecules during their transitions. A challenge that innovative magnetic resonance approaches can meet.

In this contribution, we suggest an unconventional approach to this challenge based on integrating hyperpolarization by dissolution dynamic nuclear polarization (d-DNP). By integrating d-DNP into existing structural biology methodological frameworks, we show that it is possible to characterize phase transitions involved in non-classical biomineralization monitored at atomistic detail by real-time NMR on timescales ranging from milliseconds to hours. While the established giants, XRD, EM, MD, and conventional solid- and liquid-state NMR are well fit to characterize the stable starting materials and final solids, d-DNP can draw the connection between them, allowing us to rationalize these important processes.

We demonstrate the potential using bio-silica precipitation via designer peptides with a functional RRIL motif thereby exploiting several recent developments: hybrid hydraulic/pneumatic injection systems(1) for controlled initiation of the precipitation processes, hyperpolarization protocols for various mineral salts (phosphates, silicates)(2), multiplexed detection schemes for comprehensive process monitoring,(3) and integration with computational techniques to obtain high-resolution models.(4)