scholarly journals Designing heterotropically activated allosteric conformational switches using supercharging

2020 ◽  
Vol 117 (10) ◽  
pp. 5291-5297 ◽  
Author(s):  
Peter J. Schnatz ◽  
Joseph M. Brisendine ◽  
Craig C. Laing ◽  
Bernard H. Everson ◽  
Cooper A. French ◽  
...  
Keyword(s):  
Protein Function ◽  
Intrinsically Disordered Proteins ◽  
Control Mechanism ◽  
Divalent Cations ◽  
High Surface ◽  
Model Systems ◽  
Disordered Proteins ◽  
Intrinsically Disordered ◽  
Induced Folding ◽  
Low Concentrations

Heterotropic allosteric activation of protein function, in which binding of one ligand thermodynamically activates the binding of another, different ligand or substrate, is a fundamental control mechanism in metabolism and as such has been a long-aspired capability in protein design. Here we show that greatly increasing the magnitude of a protein’s net charge using surface supercharging transforms that protein into an allosteric ligand- and counterion-gated conformational molecular switch. To demonstrate this we first modified the designed helical bundle hemoprotein H4, creating a highly charged protein which both unfolds reversibly at low ionic strength and undergoes the ligand-induced folding transition commonly observed in signal transduction by intrinsically disordered proteins in biology. As a result of the high surface-charge density, ligand binding to this protein is allosterically activated up to 1,300-fold by low concentrations of divalent cations and the polyamine spermine. To extend this process further using a natural protein, we similarly modified Escherichia coli cytochrome b562 and the resulting protein behaves in a like manner. These simple model systems not only establish a set of general engineering principles which can be used to convert natural and designed soluble proteins into allosteric molecular switches useful in biodesign, sensing, and synthetic biology, the behavior we have demonstrated––functional activation of supercharged intrinsically disordered proteins by low concentrations of multivalent ions––may be a control mechanism utilized by Nature which has yet to be appreciated.

scholarly journals New technologies to analyse protein function: an intrinsic disorder perspective

F1000Research ◽  
2020 ◽  
Vol 9 ◽  
pp. 101 ◽  
Author(s):  
Vladimir N. Uversky
Keyword(s):  
Protein Function ◽  
Intrinsically Disordered Proteins ◽  
New Technologies ◽  
Intrinsically Disordered Protein ◽  
Intrinsic Disorder ◽  
Disordered Proteins ◽  
Intrinsically Disordered ◽  
Disordered Protein ◽  
Protein Functions ◽  
Require Structure

Functions of intrinsically disordered proteins do not require structure. Such structure-independent functionality has melted away the classic rigid “lock and key” representation of structure–function relationships in proteins, opening a new page in protein science, where molten keys operate on melted locks and where conformational flexibility and intrinsic disorder, structural plasticity and extreme malleability, multifunctionality and binding promiscuity represent a new-fangled reality. Analysis and understanding of this new reality require novel tools, and some of the techniques elaborated for the examination of intrinsically disordered protein functions are outlined in this review.

scholarly journals Dynamical Oligomerisation of Histidine Rich Intrinsically Disordered Proteins Is Regulated through Zinc-Histidine Interactions

Biomolecules ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 168 ◽  
Author(s):  
Carolina Cragnell ◽  
Lasse Staby ◽  
Samuel Lenton ◽  
Birthe Kragelund ◽  
Marie Skepö
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Intrinsically Disordered Proteins ◽  
Divalent Cations ◽  
Disordered Proteins ◽  
Resonance Spectroscopy ◽  
Binding Motifs ◽  
Histatin 5 ◽  
X Ray ◽  
Intrinsically Disordered ◽  
X Ray Scattering

Intrinsically disordered proteins (IDPs) can form functional oligomers and in some cases, insoluble disease related aggregates. It is therefore vital to understand processes and mechanisms that control pathway distribution. Divalent cations including Zn2+ can initiate IDP oligomerisation through the interaction with histidine residues but the mechanisms of doing so are far from understood. Here we apply a multi-disciplinary approach using small angle X-ray scattering, nuclear magnetic resonance spectroscopy, calorimetry and computations to show that that saliva protein Histatin 5 forms highly dynamic oligomers in the presence of Zn2+. The process is critically dependent upon interaction between Zn2+ ions and distinct histidine rich binding motifs which allows for thermodynamic switching between states. We propose a molecular mechanism of oligomerisation, which may be generally applicable to other histidine rich IDPs. Finally, as Histatin 5 is an important saliva component, we suggest that Zn2+ induced oligomerisation may be crucial for maintaining saliva homeostasis.

scholarly journals Salient Features of Monomeric Alpha-Synuclein Revealed by NMR Spectroscopy

Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 428
Author(s):  
Do-Hyoung Kim ◽  
Jongchan Lee ◽  
K. Mok ◽  
Jung Lee ◽  
Kyou-Hoon Han
Keyword(s):  
Structural Biology ◽  
Protein Function ◽  
Intrinsically Disordered Proteins ◽  
Alpha Synuclein ◽  
Disordered Proteins ◽  
Strongly Correlated ◽  
Proper Understanding ◽  
Intrinsically Disordered ◽  
Structural Details ◽  
The One

Elucidating the structural details of proteins is highly valuable and important for the proper understanding of protein function. In the case of intrinsically disordered proteins (IDPs), however, obtaining the structural details is quite challenging, as the traditional structural biology tools have only limited use. Nuclear magnetic resonance (NMR) is a unique experimental tool that provides ensemble conformations of IDPs at atomic resolution, and when studying IDPs, a slightly different experimental strategy needs to be employed than the one used for globular proteins. We address this point by reviewing many NMR investigations carried out on the α-synuclein protein, the aggregation of which is strongly correlated with Parkinson’s disease.

Functions of short lifetime biological structures at large: the case of intrinsically disordered proteins

2018 ◽  
Author(s):  
Vladimir N Uversky
Keyword(s):  
Biological Networks ◽  
Protein Function ◽  
Intrinsically Disordered Proteins ◽  
Protein Molecule ◽  
Biologically Active ◽  
Disordered Proteins ◽  
Substantial Part ◽  
Binding Modes ◽  
Intrinsically Disordered ◽  
Short Lifetime

Abstract Although for more than a century a protein function was intimately associated with the presence of unique structure in a protein molecule, recent years witnessed a skyrocket rise of the appreciation of protein intrinsic disorder concept that emphasizes the importance of the biologically active proteins without ordered structures. In different proteins, the depth and breadth of disorder penetrance are different, generating an amusing spatiotemporal heterogeneity of intrinsically disordered proteins (IDPs) and intrinsically disordered protein region regions (IDPRs), which are typically described as highly dynamic ensembles of rapidly interconverting conformations (or a multitude of short lifetime structures). IDPs/IDPRs constitute a substantial part of protein kingdom and have unique functions complementary to functional repertoires of ordered proteins. They are recognized as interaction specialists and global controllers that play crucial roles in regulation of functions of their binding partners and in controlling large biological networks. IDPs/IDPRs are characterized by immense binding promiscuity and are able to use a broad spectrum of binding modes, often resulting in the formation of short lifetime complexes. In their turn, functions of IDPs and IDPRs are controlled by various means, such as numerous posttranslational modifications and alternative splicing. Some of the functions of IDPs/IDPRs are briefly considered in this review to shed some light on the biological roles of short-lived structures at large.

scholarly journals The mechanism of coupled folding-upon-binding of an intrinsically disordered protein

2020 ◽  
Author(s):  
Paul Robustelli ◽  
Stefano Piana ◽  
David E. Shaw
Keyword(s):  
Measles Virus ◽  
Intrinsically Disordered Proteins ◽  
Tertiary Structure ◽  
Disordered Proteins ◽  
Binding Process ◽  
Intrinsically Disordered ◽  
Disordered Protein ◽  
Induced Folding ◽  
Helical Content ◽  
Intermolecular Contacts

AbstractIntrinsically disordered proteins (IDPs), which in isolation do not adopt a well-defined tertiary structure but instead populate a structurally heterogeneous ensemble of interconverting states, play important roles in many biological pathways. IDPs often fold into ordered states upon binding to their physiological interaction partners (a so-called “folding-upon-binding” process), but it has proven difficult to obtain an atomic-level description of the structural mechanisms by which they do so. Here, we describe in atomic detail the folding-upon-binding mechanism of an IDP segment to its binding partner, as observed in unbiased molecular dynamics simulations. In our simulations, we observed over 70 binding and unbinding events between the α-helical molecular recognition element (α-MoRE) of the intrinsically disordered C-terminal domain of the measles virus nucleoprotein (NTAIL) and the X domain (XD) of the measles virus phosphoprotein complex. We found that folding-upon-binding primarily occurred through induced-folding pathways (in which intermolecular contacts form before or concurrently with the secondary structure of the disordered protein)—an observation supported by previous experiments—and that the transition state ensemble was characterized by the formation of just a few key intermolecular contacts, and was otherwise highly structurally heterogeneous. We found that when a large amount of helical content was present early in a transition path, NTAIL typically unfolded, then refolded after additional intermolecular contacts formed. We also found that, among conformations with similar numbers of intermolecular contacts, those with less helical content had a higher probability of ultimately forming the native complex than conformations with more helical content, which were more likely to unbind. These observations suggest that even after intermolecular contacts have formed, disordered regions can have a kinetic advantage over folded regions in the folding-upon-binding process.

scholarly journals HACANCOi: a new Hα-detected experiment for backbone resonance assignment of intrinsically disordered proteins

2020 ◽  
Vol 74 (12) ◽  
pp. 741-752
Author(s):  
Mikael Karjalainen ◽  
Helena Tossavainen ◽  
Maarit Hellman ◽  
Perttu Permi
Keyword(s):  
Intrinsically Disordered Proteins ◽  
Chemical Exchange ◽  
Relaxation Times ◽  
High Sensitivity ◽  
Model Systems ◽  
Disordered Proteins ◽  
Sequential Assignment ◽  
Coherence Transfer ◽  
Intrinsically Disordered ◽  
Folded Proteins

AbstractUnidirectional coherence transfer is highly efficient in intrinsically disordered proteins (IDPs). Their elevated ps-ns timescale dynamics ensures long transverse (T2) relaxation times allowing sophisticated coherence transfer pathway selection in comparison to folded proteins. 1Hα-detection ensures non-susceptibility to chemical exchange with the solvent and enables chemical shift assignment of consecutive proline residues, typically abundant in IDPs. However, many IDPs undergo a disorder-to-order transition upon interaction with their target protein, which leads to the loss of the favorable relaxation properties. Long coherence transfer routes now result in prohibitively large decrease in sensitivity. We introduce a novel 4D 1Hα-detected experiment HACANCOi, together with its 3D implementation, which warrant high sensitivity for the assignment of proline-rich regions in IDPs in complex with a globular protein. The experiment correlates 1Hαi, 13Cαi, 15Ni and $$^{13} C^{\prime}_{i}$$ 13 C i ′ spins by transferring the magnetization concomitantly from 13Cαi to 15Ni and $$^{13} C^{\prime}_{i}$$ 13 C i ′ . The B1 domain of protein G (GB1), and the enteropathogenic E.coli EspF in complex with human SNX9 SH3, serve as model systems to demonstrate the attainable sensitivity and successful sequential assignment.

scholarly journals Common Functions of Disordered Proteins across Evolutionary Distant Organisms

2020 ◽  
Vol 21 (6) ◽  
pp. 2105 ◽  
Author(s):  
Arndt Wallmann ◽  
Christopher Kesten
Keyword(s):  
Protein Function ◽  
Intrinsically Disordered Proteins ◽  
Disordered Proteins ◽  
Plant Proteins ◽  
Sequence Structure ◽  
Intrinsically Disordered ◽  
Bioinformatic Approaches ◽  
The Common ◽  
Function Relationship

Intrinsically disordered proteins and regions typically lack a well-defined structure and thus fall outside the scope of the classic sequence–structure–function relationship. Hence, classic sequence- or structure-based bioinformatic approaches are often not well suited to identify homology or predict the function of unknown intrinsically disordered proteins. Here, we give selected examples of intrinsic disorder in plant proteins and present how protein function is shared, altered or distinct in evolutionary distant organisms. Furthermore, we explore how examining the specific role of disorder across different phyla can provide a better understanding of the common features that protein disorder contributes to the respective biological mechanism.

Disorder-function relationships for the cell cycle regulatory proteins p21 and p27

2012 ◽  
Vol 393 (4) ◽  
pp. 259-274 ◽  
Author(s):  
Diana M. Mitrea ◽  
Mi-Kyung Yoon ◽  
Li Ou ◽  
Richard W. Kriwacki
Keyword(s):  
Cell Division ◽  
Molecular Mechanisms ◽  
Intrinsically Disordered Proteins ◽  
Tertiary Structure ◽  
Structural Features ◽  
Disordered Proteins ◽  
Cellular Functions ◽  
Intrinsically Disordered ◽  
Induced Folding ◽  
Cell Cycle Regulatory Proteins

Abstract The classic structure-function paradigm has been challenged by a recently identified class of proteins: intrinsically disordered proteins (IDPs). Despite their lack of stable secondary or tertiary structure, IDPs are prevalent in all forms of life and perform myriad cellular functions, including signaling and regulation. Importantly, disruption of IDP homeostasis is associated with numerous human diseases, including cancer and neurodegeneration. Despite wide recognition of IDPs, the molecular mechanisms underlying their functions are not fully understood. Here we review the structural features and disorder-function relationships for p21 and p27, two cyclin-dependent kinase (Cdk) regulators involved in controlling cell division and fate. Studies of p21 bound to Cdk2/cyclin A revealed that a helix stretching mechanism mediates binding promiscuity. Further, investigations of Tyr88-phosphorylated p27 identified a signaling conduit that controls cell division and is disrupted in certain cancers. These mechanisms rely upon a balance between nascent structure in the free state, induced folding upon binding, and persistent flexibility within functional complexes. Although these disorder-function relationships are likely to be recapitulated in other IDPs, it is also likely that the vocabulary of their mechanisms is much more extensive than is currently understood. Further study of the physical properties of IDPs and elucidation of their links with function are needed to fully understand the mechanistic language of IDPs.

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