Studies of proline conformational dynamics in IDPs by 13C-detected cross-correlated NMR relaxation

Marco Schiavina, Ruth Konrat, Irene Ceccolini, Borja Mateos, Robert Konrat (Corresponding author), Isabella C. Felli (Corresponding author), Roberta Pierattelli (Corresponding author)

Publications: Contribution to journalArticlePeer Reviewed

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 languageEnglish
Article number107539
Number of pages8
JournalJournal of Magnetic Resonance
Volume354
Early online date11 Aug 2023
DOIs
Publication statusPublished - Sep 2023

Austrian Fields of Science 2012

  • 106023 Molecular biology

Keywords

  • C direct detection
  • Cross correlation
  • Dynamics
  • Intrinsically disordered proteins
  • Proline

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