Abstract
Intrinsically disordered proteins (IDPs) are significantly enriched in proline residues, which can populate specific local secondary structural elements called PPII helices, characterized by small packing densities. Proline is often thought to promote disorder, but it can participate in specific π·CH interactions with aromatic side chains resulting in reduced conformational flexibilities of the polypeptide. Differential local motional dynamics are relevant for the stabilization of preformed structural elements and can serve as nucleation sites for the establishment of long-range interactions. NMR experiments to probe the dynamics of proline ring systems would thus be highly desirable. Here we present a pulse scheme based on 13C detection to quantify dipole–dipole cross-correlated relaxation (CCR) rates at methylene CH2 groups in proline residues. Applying 13C-CON detection strategy provides exquisite spectral resolution allowing applications also to high molecular weight IDPs even in conditions approaching the physiological ones. The pulse scheme is illustrated with an application to the 220 amino acids long protein Osteopontin, an extracellular cytokine involved in inflammation and cancer progression, and a construct in which three proline-aromatic sequence patches have been mutated.
Original language | English |
---|---|
Article number | 107539 |
Number of pages | 8 |
Journal | Journal of Magnetic Resonance |
Volume | 354 |
Early online date | 11 Aug 2023 |
DOIs | |
Publication status | Published - Sep 2023 |
Austrian Fields of Science 2012
- 106023 Molecular biology
Keywords
- C direct detection
- Cross correlation
- Dynamics
- Intrinsically disordered proteins
- Proline