scholarly journals Ligand Clouds around Protein Clouds: A Scenario of Ligand Binding with Intrinsically Disordered Proteins

2013 ◽  
Vol 9 (10) ◽  
pp. e1003249 ◽  
Author(s):  
Fan Jin ◽  
Chen Yu ◽  
Luhua Lai ◽  
Zhirong Liu
Keyword(s):  
Ligand Binding ◽  
Intrinsically Disordered Proteins ◽  
Disordered Proteins ◽  
Intrinsically Disordered

scholarly journals NMR Line Shapes in Molecular Mechanisms with Ligand Binding and Multiple Conformers

2020 ◽  
Author(s):  
Evgenii L Kovrigin
Keyword(s):  
Ligand Binding ◽  
Molecular Mechanisms ◽  
Intrinsically Disordered Proteins ◽  
Chemical Shifts ◽  
Disordered Proteins ◽  
Biological Macromolecules ◽  
Induced Fit ◽  
Line Shapes ◽  
Intrinsically Disordered ◽  
Specific Effects

ABSTRACTInteractions of ligands with biological macromolecules are sensitively detected through changes of chemical shifts and line shapes of the NMR signals. This paper reports a mathematical analysis and simulations of NMR line shapes expected in titrations when ligand binding is coupled to multiple isomerization transitions. Such molecular mechanisms may correspond to ligand binding by intrinsically disordered proteins or by autoinhibited enzymes. Based on the simulation results, we anticipate several specific effects that may be observed in practice. First, the presence of non-binding conformers of the receptor molecule leads to a remarkable broadening in the binding transition even if the exchange between binding and non-binding conformers is very slow. Second, the ligand-binding mechanisms involving induced fit are expected to demonstrate deceptively decelerated exchange regimes even when the underlying kinetics are very fast. Conversely, the observation of fast-exchange shifting resonances with modest line-broadening (“marching peaks”) in practical NMR titrations may involve conformational selection transitions but less likely to be observed for the induced fit. Finally, in auto-inhibited molecules that open to form multiple binding-competent conformers, the fast dynamics of opening/closing transition are capable of masking the true kinetics of interconversion among transiently open forms of the receptor.

scholarly journals Identification of ligand binding sites in intrinsically disordered proteins with a differential binding score

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Qiao-Hong Chen ◽  
V. V. Krishnan
Keyword(s):  
Drug Discovery ◽  
Ligand Binding ◽  
Binding Sites ◽  
Intrinsically Disordered Proteins ◽  
Random Coil ◽  
Disordered Proteins ◽  
Intrinsically Disordered ◽  
Binding Score ◽  
Ligand Binding Sites ◽  
Differential Binding

AbstractScreening ligands directly binding to an ensemble of intrinsically disordered proteins (IDP) to discover potential hits or leads for new drugs is an emerging but challenging area as IDPs lack well-defined and ordered 3D-protein structures. To explore a new IDP-based rational drug discovery strategy, a differential binding score (DIBS) is defined. The basis of DIBS is to quantitatively determine the binding preference of a ligand to an ensemble of conformations specified by IDP versus such preferences to an ensemble of random coil conformations of the same protein. Ensemble docking procedures performed on repeated sampling of conformations, and the results tested for statistical significance determine the preferential ligand binding sites of the IDP. The results of this approach closely reproduce the experimental data from recent literature on the binding of the ligand epigallocatechin gallate (EGCG) to the intrinsically disordered N-terminal domain of the tumor suppressor p53. Combining established approaches in developing a new method to screen ligands against IDPs could be valuable as a screening tool for IDP-based drug discovery.

Sequence Specificity Despite Intrinsic Disorder: How a Disease-Associated Val/Met Polymorphism Shifts Tertiary Interactions in a Long Disordered Protein

2019 ◽  
Author(s):  
Ruchi Lohia ◽  
Reza Salari ◽  
Grace Brannigan
Keyword(s):  
Secondary Structure ◽  
Electrostatic Interactions ◽  
Intrinsically Disordered Proteins ◽  
Disordered Proteins ◽  
Sequence Specificity ◽  
Intrinsically Disordered ◽  
Specific Effects ◽  
Heterogeneous Polymer ◽  
Non Local ◽  
Dynamics Simulations

<div>The role of electrostatic interactions and mutations that change charge states in intrinsically disordered proteins (IDPs) is well-established, but many disease-associated mutations in IDPs are charge-neutral. The Val66Met single nucleotide polymorphism (SNP) encodes a hydrophobic-to-hydrophobic mutation at the midpoint of the prodomain of precursor brain-derived neurotrophic factor (BDNF), one of the earliest SNPs to be associated with neuropsychiatric disorders, for which the underlying molecular mechanism is unknown. Here we report on over 250 μs of fully-atomistic, explicit solvent, temperature replica exchange molecular dynamics simulations of the 91 residue BDNF prodomain, for both the V66 and M66 sequence.</div><div>The simulations were able to correctly reproduce the location of both local and non-local secondary changes due to the Val66Met mutation when compared with NMR spectroscopy. We find that the local structure change is mediated via entropic and sequence specific effects. We show that the highly disordered prodomain can be meaningfully divided into domains based on sequence alone. Monte Carlo simulations of a self-excluding heterogeneous polymer, with monomers representing each domain, suggest the sequence would be effectively segmented by the long, highly disordered polyampholyte near the sequence midpoint. This is qualitatively consistent with observed interdomain contacts within the BDNF prodomain, although contacts between the two segments are enriched relative to the self-excluding polymer. The Val66Met mutation increases interactions across the boundary between the two segments, due in part to a specific Met-Met interaction with a Methionine in the other segment. This effect propagates to cause the non-local change in secondary structure around the second methionine, previously observed in NMR. The effect is not mediated simply via changes in inter-domain contacts but is also dependent on secondary structure formation around residue 66, indicating a mechanism for secondary structure coupling in disordered proteins. </div>

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