Helix handedness inversion in arylamide foldamers: elucidation and free energy profile of a hopping mechanism

2016 ◽  
Vol 52 (4) ◽  
pp. 669-672 ◽  
Author(s):  
Ara M. Abramyan ◽  
Zhiwei Liu ◽  
Vojislava Pophristic
Keyword(s):  
Free Energy ◽  
Energy Landscape ◽  
Free Energy Landscape ◽  
Energy Profile ◽  
Free Energy Profile ◽  
Hopping Mechanism ◽  
Arylamide Foldamers

The free energy landscape and conformations of minima and intermediates along the stepwise handedness inversion pathway, proceeding through the simultaneous unfolding/folding of adjacent monomer–monomer linkages, for a helical arylamide foldamer.

The experimental survey of protein-folding energy landscapes

2005 ◽  
Vol 38 (3) ◽  
pp. 245-288 ◽  
Author(s):  
Mikael Oliveberg ◽  
Peter G. Wolynes
Keyword(s):  
Free Energy ◽  
Protein Folding ◽  
Transition State ◽  
Energy Landscape ◽  
Energy Profile ◽  
Global Features ◽  
Value Analysis ◽  
Free Energy Profile ◽  
State Ensemble ◽  
Transition State Ensemble

1. Introduction 22. The macroscopic and microscopic views of protein folding 22.1 The macroscopic view: the experimental folding free-energy profile 22.2 The microscopic view: an underlying energy landscape 33. The micro to macro projection: from an energy landscape to a free-energy profile 64. Global features of the protein folding transition-state ensemble 124.1 Overall transition state location β[Dagger]: a measure of compactness 124.2 What makes folding so robust ? 135. Structural characterization of the transition-state ensemble 165.1 Insights from ϕ-value analysis 166. Deviations from ideality 206.1 β[Dagger] shifts along seemingly robust trajectories 216.2 Anomalous ϕ values, frustration and inhomogeneities 257. Intermediates 288. Detours, traps and frustration 298.1 Premature collapse and non-native trapping 299. Diffusion on the energy landscape and the elementary events of protein folding 3010. Malleability of folding routes: changes of the dominant collective coordinates for folding 3311. The evolution of the shape of the energy landscape 3511.1 Negative design: the hidden dimension of the folding code 3512. Mechanistic multiplicity and evolutionary choice 3613. Acknowledgements 3714. References 38We review what has been learned about the protein-folding problem from experimental kinetic studies. These studies reveal patterns of both great richness and surprising simplicity. The patterns can be interpreted in terms of proteins possessing an energy landscape which is largely, but not completely, funnel-like. Issues such as speed limitations of folding, the robustness of folding, the origin of barriers and cooperativity and the ensemble nature of transition states, intermediate and traps are assessed using the results from several experimental groups highlighting energy-landscape ideas as an interpretive framework.

Determination of Base Flipping Free Energy Landscapes from Nonequilibrium Stratification

2019 ◽  
Author(s):  
Xiaohui Wang ◽  
Zhaoxi Sun
Keyword(s):  
Free Energy ◽  
Energy Landscape ◽  
Sampling Technique ◽  
Umbrella Sampling ◽  
Energy Simulation ◽  
Nonlinear Dependence ◽  
Free Energy Landscape ◽  
Convergence Criterion ◽  
Base Flipping ◽  
Convergence Behavior

<p>Correct calculation of the variation of free energy upon base flipping is crucial in understanding the dynamics of DNA systems. The free energy landscape along the flipping pathway gives the thermodynamic stability and the flexibility of base-paired states. Although numerous free energy simulations are performed in the base flipping cases, no theoretically rigorous nonequilibrium techniques are devised and employed to investigate the thermodynamics of base flipping. In the current work, we report a general nonequilibrium stratification scheme for efficient calculation of the free energy landscape of base flipping in DNA duplex. We carefully monitor the convergence behavior of the equilibrium sampling based free energy simulation and the nonequilibrium stratification and determine the empirical length of time blocks required for converged sampling. Comparison between the performances of equilibrium umbrella sampling and nonequilibrium stratification is given. The results show that nonequilibrium free energy simulation is able to give similar accuracy and efficiency compared with the equilibrium enhanced sampling technique in the base flipping cases. We further test a convergence criterion we previously proposed and it comes out that the convergence behavior determined by this criterion agrees with those given by the time-invariant behavior of PMF and the nonlinear dependence of standard deviation on the sample size. </p>

The Perturbed Free Energy Landscape: Linking Ligand Binding to Biomolecular Folding

ChemBioChem ◽  
2020 ◽  
Author(s):  
fareed aboul-ela ◽  
Abdallah S Abdelsatter ◽  
Youssef Mansour
Keyword(s):  
Free Energy ◽  
Ligand Binding ◽  
Energy Landscape ◽  
Free Energy Landscape

Free energy profile analysis to identify factors activating the aggregation-induced emission of a cyanostilbene derivative

2021 ◽  
Author(s):  
Norifumi Yamamoto
Keyword(s):  
Free Energy ◽  
Profile Analysis ◽  
Energy Profile ◽  
Contributing Factors ◽  
Free Energy Profile ◽  
Aggregation Induced Emission ◽  
Energy Profiles ◽  
Free Energy Profiles

The contributing factors that cause the aggregation-induced emission (AIE) are determined by identifying characteristic differences in the free energy profiles of the AIE processes of the AIE-active E-form of CN-MBE and the inactive Z-form.

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