Cold denaturation of a protein dimer monitored at atomic resolution

Abstract

Protein folding and unfolding are crucial for a range of biological phenomena and human diseases. Defining the pathways of protein folding and unfolding is crucial for understanding the origins of a range of biological phenomena and human diseases. However, little is known about the involved structural changes because the species populated during folding and unfolding are highly transient and therefore difficult to grasp by current technology. We have overcome these limitations by a combination of nuclear magnetic resonance spectroscopy with cold-induced unfolding of a homodimeric protein in supercooled solution. Seven three-dimensional structures of the Enterococcus faecalis repressor protein CylR2 at temperatures from 25 °C to −16 °C reveal a progressive dissociation of the dimer into a native-like monomeric intermediate followed by transition into a highly dynamic, partially folded state. The core of the partially folded state appears critical for biological function and misfolding.

Phosphorylation Drives a Dynamic Switch in Serine/Arginine-Rich Proteins

“…Notably, phosphorylated SRSF1(RS1) was not as rigid as secondary structure elements in globular proteins. In line with the possibility of significant mobility in structured molecules, we recently showed that the backbone of a well-defined protein folding intermediate remained highly mobile (Jaremko et al, 2013). To take into account the mobility of phosphorylated SRSF1(RS1), we described SRSF1(RpS1) by ensembles of 30 conformers that are in agreement with a large number of NMR observables.…”

The metallacrowns as templates for spontaneous self-assembly of polypeptides into a tetrahelical bundle

“…Therefore, also the possible salt-bridges between the side chains of Glu and Lys stabilizing the four-helices tertiary structure can be excluded. 15 Discussion. The mass spectrometric measurements demonstrate unambiguously that peptides containing a b-aminohydroxamic or an imidazoilo hydroxamic moiety at C-termini formed the supramolecular structures with the compositions corresponding to those of metallacrowns.…”

Non‐Debye frustrated hydration steers biomolecular association: interfacial tension for the drug designer

“…A tight correlation ( R 2 = 0.921, Fig. B) is obtained between dimer/monomer molar ratio X , a measure of association propensity obtained from average values of hydrodynamic radius , and the interfacial tension. This correlation validates the variational frustration principle and its dynamic steering role in complex formation.…”

“…We demonstrate that frustration‐related water polarization steers protein–protein (PP) associations with high specificity and drives the dynamics of complex formation. The validation of these assertions entails contrasting optimally frustrated states with affinity scanning of PP‐interfaces in complexes that assemble to mitigate frustrated hydration of free subunits, and with NMR information on the dynamics of complex formation . Subsequently, we identify the optimal sequence of steps that maximize the mitigation of interfacial tension, funneling complex formation.…”