Effects of Fluorination on the Folding Kinetics of a Heterodimeric Coiled Coil

ChemBioChem ◽  
2009 ◽  
Vol 10 (18) ◽  
pp. 2867-2870 ◽  
Author(s):  
Mario Salwiczek ◽  
Beate Koksch
Biochemistry ◽  
1999 ◽  
Vol 38 (8) ◽  
pp. 2601-2609 ◽  
Author(s):  
Roby P. Bhattacharyya ◽  
Tobin R. Sosnick

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 347
Author(s):  
Jiabin Huang ◽  
Björn Voß

Studying the folding kinetics of an RNA can provide insight into its function and is thus a valuable method for RNA analyses. Computational approaches to the simulation of folding kinetics suffer from the exponentially large folding space that needs to be evaluated. Here, we present a new approach that combines structure abstraction with evolutionary conservation to restrict the analysis to common parts of folding spaces of related RNAs. The resulting algorithm can recapitulate the folding kinetics known for single RNAs and is able to analyse even long RNAs in reasonable time. Our program RNAliHiKinetics is the first algorithm for the simulation of consensus folding kinetics and addresses a long-standing problem in a new and unique way.


2012 ◽  
Vol 103 (7) ◽  
pp. 1555-1565 ◽  
Author(s):  
Tzachi Hagai ◽  
Ariel Azia ◽  
Emmanuel Trizac ◽  
Yaakov Levy

Biochemistry ◽  
2006 ◽  
Vol 45 (35) ◽  
pp. 10504-10511 ◽  
Author(s):  
Jasmin Faraone-Mennella ◽  
F. Akif Tezcan ◽  
Harry B. Gray ◽  
Jay R. Winkler
Keyword(s):  

2015 ◽  
Vol 585 ◽  
pp. 52-63 ◽  
Author(s):  
Rishu Jain ◽  
Rajesh Kumar ◽  
Sandeep Kumar ◽  
Ritika Chhabra ◽  
Mukesh Chand Agarwal ◽  
...  

2019 ◽  
Vol 116 (17) ◽  
pp. 8137-8142 ◽  
Author(s):  
Malwina Szczepaniak ◽  
Manuel Iglesias-Bexiga ◽  
Michele Cerminara ◽  
Mourad Sadqi ◽  
Celia Sanchez de Medina ◽  
...  

Protein (un)folding rates depend on the free-energy barrier separating the native and unfolded states and a prefactor term, which sets the timescale for crossing such barrier or folding speed limit. Because extricating these two factors is usually unfeasible, it has been common to assume a constant prefactor and assign all rate variability to the barrier. However, theory and simulations postulate a protein-specific prefactor that contains key mechanistic information. Here, we exploit the special properties of fast-folding proteins to experimentally resolve the folding rate prefactor and investigate how much it varies among structural homologs. We measure the ultrafast (un)folding kinetics of five natural WW domains using nanosecond laser-induced temperature jumps. All five WW domains fold in microseconds, but with a 10-fold difference between fastest and slowest. Interestingly, they all produce biphasic kinetics in which the slower phase corresponds to reequilibration over the small barrier (<3RT) and the faster phase to the downhill relaxation of the minor population residing at the barrier top [transition state ensemble (TSE)]. The fast rate recapitulates the 10-fold range, demonstrating that the folding speed limit of even the simplest all-β fold strongly depends on the amino acid sequence. Given this fold’s simplicity, the most plausible source for such prefactor differences is the presence of nonnative interactions that stabilize the TSE but need to break up before folding resumes. Our results confirm long-standing theoretical predictions and bring into focus the rate prefactor as an essential element for understanding the mechanisms of folding.


2020 ◽  
Vol 117 (11) ◽  
pp. 5844-5852 ◽  
Author(s):  
Alberto Ceccon ◽  
Vitali Tugarinov ◽  
Rodolfo Ghirlando ◽  
G. Marius Clore

Human profilin I reduces aggregation and concomitant toxicity of the polyglutamine-containing N-terminal region of the huntingtin protein encoded by exon 1 (httex1) and responsible for Huntington’s disease. Here, we investigate the interaction of profilin with httex1using NMR techniques designed to quantitatively analyze the kinetics and equilibria of chemical exchange at atomic resolution, including relaxation dispersion, exchange-induced shifts, and lifetime line broadening. We first show that the presence of two polyproline tracts in httex1, absent from a shorter huntingtin variant studied previously, modulates the kinetics of the transient branched oligomerization pathway that precedes nucleation, resulting in an increase in the populations of the on-pathway helical coiled-coil dimeric and tetrameric species (τex≤ 50 to 70 μs), while leaving the population of the off-pathway (nonproductive) dimeric species largely unaffected (τex∼750 μs). Next, we show that the affinity of a single molecule of profilin to the polyproline tracts is in the micromolar range (Kdiss∼ 17 and ∼ 31 μM), but binding of a second molecule of profilin is negatively cooperative, with the affinity reduced ∼11-fold. The lifetime of a 1:1 complex of httex1with profilin, determined using a shorter huntingtin variant containing only a single polyproline tract, is shown to be on the submillisecond timescale (τex∼ 600 μs andKdiss∼ 50 μM). Finally, we demonstrate that, in stable profilin–httex1complexes, the productive oligomerization pathway, leading to the formation of helical coiled-coil httex1tetramers, is completely abolished, and only the pathway resulting in “nonproductive” dimers remains active, thereby providing a mechanistic basis for how profilin reduces aggregation and toxicity of httex1.


2020 ◽  
Vol 118 (3) ◽  
pp. 335a
Author(s):  
Emil L. Kristoffersen ◽  
Andrea Coletta ◽  
Line Lund ◽  
Birgit Schiøtt ◽  
Victoria Birkedal

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