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1.
Proc Natl Acad Sci U S A ; 121(24): e2316892121, 2024 Jun 11.
Article in English | MEDLINE | ID: mdl-38833472

ABSTRACT

The loss of function of AAA (ATPases associated with diverse cellular activities) mechanoenzymes has been linked to diseases, and small molecules that activate these proteins can be powerful tools to probe mechanisms and test therapeutic hypotheses. Unlike chemical inhibitors that can bind a single conformational state to block enzyme function, activator binding must be permissive to different conformational states needed for mechanochemistry. However, we do not know how AAA proteins can be activated by small molecules. Here, we focus on valosin-containing protein (VCP)/p97, an AAA unfoldase whose loss of function has been linked to protein aggregation-based disorders, to identify druggable sites for chemical activators. We identified VCP ATPase Activator 1 (VAA1), a compound that dose-dependently stimulates VCP ATPase activity up to ~threefold. Our cryo-EM studies resulted in structures (ranging from ~2.9 to 3.7 Å-resolution) of VCP in apo and ADP-bound states and revealed that VAA1 binds an allosteric pocket near the C-terminus in both states. Engineered mutations in the VAA1-binding site confer resistance to VAA1, and furthermore, modulate VCP activity. Mutation of a phenylalanine residue in the VCP C-terminal tail that can occupy the VAA1 binding site also stimulates ATPase activity, suggesting that VAA1 acts by mimicking this interaction. Together, our findings uncover a druggable allosteric site and a mechanism of enzyme regulation that can be tuned through small molecule mimicry.


Subject(s)
Valosin Containing Protein , Valosin Containing Protein/metabolism , Valosin Containing Protein/chemistry , Valosin Containing Protein/genetics , Allosteric Regulation , Humans , Protein Binding , Molecular Mimicry , Cryoelectron Microscopy , Adenosine Triphosphatases/metabolism , Adenosine Triphosphatases/chemistry , Binding Sites , Allosteric Site , Models, Molecular , Protein Conformation
2.
Int J Mol Sci ; 25(9)2024 May 01.
Article in English | MEDLINE | ID: mdl-38732174

ABSTRACT

Understanding mechanisms of allosteric regulation remains elusive for the SARS-CoV-2 spike protein, despite the increasing interest and effort in discovering allosteric inhibitors of the viral activity and interactions with the host receptor ACE2. The challenges of discovering allosteric modulators of the SARS-CoV-2 spike proteins are associated with the diversity of cryptic allosteric sites and complex molecular mechanisms that can be employed by allosteric ligands, including the alteration of the conformational equilibrium of spike protein and preferential stabilization of specific functional states. In the current study, we combine conformational dynamics analysis of distinct forms of the full-length spike protein trimers and machine-learning-based binding pocket detection with the ensemble-based ligand docking and binding free energy analysis to characterize the potential allosteric binding sites and determine structural and energetic determinants of allosteric inhibition for a series of experimentally validated allosteric molecules. The results demonstrate a good agreement between computational and experimental binding affinities, providing support to the predicted binding modes and suggesting key interactions formed by the allosteric ligands to elicit the experimentally observed inhibition. We establish structural and energetic determinants of allosteric binding for the experimentally known allosteric molecules, indicating a potential mechanism of allosteric modulation by targeting the hinges of the inter-protomer movements and blocking conformational changes between the closed and open spike trimer forms. The results of this study demonstrate that combining ensemble-based ligand docking with conformational states of spike protein and rigorous binding energy analysis enables robust characterization of the ligand binding modes, the identification of allosteric binding hotspots, and the prediction of binding affinities for validated allosteric modulators, which is consistent with the experimental data. This study suggested that the conformational adaptability of the protein allosteric sites and the diversity of ligand bound conformations are both in play to enable efficient targeting of allosteric binding sites and interfere with the conformational changes.


Subject(s)
Allosteric Site , Molecular Docking Simulation , Molecular Dynamics Simulation , Protein Binding , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Allosteric Regulation , SARS-CoV-2/drug effects , SARS-CoV-2/metabolism , Ligands , Humans , Binding Sites , Protein Conformation , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Antiviral Agents/metabolism , Protein Multimerization , Machine Learning
3.
Int J Mol Sci ; 25(9)2024 Apr 26.
Article in English | MEDLINE | ID: mdl-38731943

ABSTRACT

Protein kinases are essential regulators of cell function and represent one of the largest and most diverse protein families. They are particularly influential in signal transduction and coordinating complex processes like the cell cycle. Out of the 518 human protein kinases identified, 478 are part of a single superfamily sharing catalytic domains that are related in sequence. The dysregulation of protein kinases due to certain mutations has been associated with various diseases, including cancer. Although most of the protein kinase inhibitors identified as type I or type II primarily target the ATP-binding pockets of kinases, the structural and sequential resemblances among these pockets pose a significant challenge for selective inhibition. Therefore, targeting allosteric pockets that are beside highly conserved ATP pockets has emerged as a promising strategy to prevail current limitations, such as poor selectivity and drug resistance. In this article, we compared the binding pockets of various protein kinases for which allosteric (type III) inhibitors have already been developed. Additionally, understanding the structure and shape of existing ligands could aid in identifying key interaction sites within the allosteric pockets of kinases. This comprehensive review aims to facilitate the design of more effective and selective allosteric inhibitors.


Subject(s)
Allosteric Site , Protein Kinase Inhibitors , Protein Kinases , Humans , Protein Kinase Inhibitors/pharmacology , Protein Kinase Inhibitors/chemistry , Protein Kinases/metabolism , Protein Kinases/chemistry , Allosteric Regulation , Binding Sites , Protein Binding , Ligands , Adenosine Triphosphate/metabolism , Adenosine Triphosphate/chemistry , Catalytic Domain , Models, Molecular
4.
Int J Mol Sci ; 25(10)2024 May 14.
Article in English | MEDLINE | ID: mdl-38791406

ABSTRACT

The allosteric inhibition of insulin-like growth factor receptor 1 kinase (IGF1RK) is a potential strategy to overcome selectivity barriers for targeting receptor tyrosine kinases. We constructed structural models of a series of 12 indole-butyl-amine derivatives that have been reported as allosteric inhibitors of IGF1RK. We further studied the dynamics and interactions of each inhibitor in the allosteric pocket via all-atom explicit-solvent molecular dynamics (MD) simulations. We discovered that a bulky carbonyl substitution at the R1 indole ring is structurally unfavorable for inhibitor binding in the IGF1RK allosteric pocket. Moreover, we found that the most potent derivative (termed C11) acquires a distinct conformation: forming an allosteric pocket channel with better shape complementarity and interactions with the receptor. In addition to a hydrogen-bonding interaction with V1063, the cyano derivative C11 forms a stable hydrogen bond with M1156, which is responsible for its unique binding conformation in the allosteric pocket. Our findings show that the positioning of chemical substituents with different pharmacophore features at the R1 indole ring influences molecular interactions and binding conformations of indole-butyl-amine derivatives and, hence, dramatically affects their potencies. Our results provide a structural framework for the design of allosteric inhibitors with improved affinities and specificities against IGF1RK.


Subject(s)
Molecular Dynamics Simulation , Protein Kinase Inhibitors , Receptor, IGF Type 1 , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Allosteric Regulation , Receptor, IGF Type 1/antagonists & inhibitors , Receptor, IGF Type 1/chemistry , Receptor, IGF Type 1/metabolism , Humans , Hydrogen Bonding , Allosteric Site , Indoles/chemistry , Indoles/pharmacology , Protein Binding , Structure-Activity Relationship , Models, Molecular
5.
J Phys Chem B ; 128(20): 4996-5007, 2024 May 23.
Article in English | MEDLINE | ID: mdl-38747451

ABSTRACT

Glycine receptors are pentameric ligand-gated ion channels that conduct chloride ions across postsynaptic membranes to facilitate fast inhibitory neurotransmission. In addition to gating by the glycine agonist, interactions with lipids and other compounds in the surrounding membrane environment modulate their function, but molecular details of these interactions remain unclear, in particular, for cholesterol. Here, we report coarse-grained simulations in a model neuronal membrane for three zebrafish glycine receptor structures representing apparent resting, open, and desensitized states. We then converted the systems to all-atom models to examine detailed lipid interactions. Cholesterol bound to the receptor at an outer-leaflet intersubunit site, with a preference for the open and desensitized versus resting states, indicating that it can bias receptor function. Finally, we used short atomistic simulations and iterative amino acid perturbations to identify residues that may mediate allosteric gating transitions. Frequent cholesterol contacts in atomistic simulations clustered with residues identified by perturbation analysis and overlapped with mutations influencing channel function and pathology. Cholesterol binding at this site was also observed in a recently reported pig heteromeric glycine receptor. These results indicate state-dependent lipid interactions relevant to allosteric transitions of glycine receptors, including specific amino acid contacts applicable to biophysical modeling and pharmaceutical design.


Subject(s)
Cholesterol , Molecular Dynamics Simulation , Receptors, Glycine , Receptors, Glycine/chemistry , Receptors, Glycine/metabolism , Cholesterol/chemistry , Cholesterol/metabolism , Animals , Allosteric Site , Zebrafish
6.
J Mol Graph Model ; 130: 108789, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38718434

ABSTRACT

Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that modulates integrin and growth factor signaling pathways and is implicated in cancer cell migration, proliferation, and survival. Over the past decade various, FAK kinase, FERM, and FAT domain inhibitors have been reported and a few kinase domain inhibitors are under clinical consideration. However, few of them were identified as multikinase inhibitors. In kinase drug design selectivity is always a point of concern, to improve selectivity allosteric inhibitor development is the best choice. The current research utilized a pharmacophore modeling (PM) approach to identify novel allosteric inhibitors of FAK. The all-available allosteric inhibitor bound 3D structures with PDB ids 4EBV, 4EBW, and 4I4F were utilized for the pharmacophore modeling. The validated PM models were utilized to map a database of 770,550 compounds prepared from ZINC, EXIMED, SPECS, ASINEX, and InterBioScreen, aiming to identify potential allosteric inhibitors. The obtained compounds from screening step were forwarded to molecular docking (MD) for the prediction of binding orientation inside the allosteric site and the results were evaluated with the known FAK allosteric inhibitor (REF). Finally, 14 FAK-inhibitor complexes were selected from the docking study and were studied under molecular dynamics simulations (MDS) for 500 ns. The complexes were ranked according to binding free energy (BFE) and those demonstrated higher affinity for allosteric site of FAK than REF inhibitors were selected. The selected complexes were further analyzed for intermolecular interactions and finally, three potential allosteric inhibitor candidates for the inhibition of FAK protein were identified. We believe that identified scaffolds may help in drug development against FAK as an anticancer agent.


Subject(s)
Focal Adhesion Protein-Tyrosine Kinases , Molecular Docking Simulation , Molecular Dynamics Simulation , Protein Kinase Inhibitors , Protein Kinase Inhibitors/chemistry , Protein Kinase Inhibitors/pharmacology , Allosteric Regulation , Focal Adhesion Protein-Tyrosine Kinases/antagonists & inhibitors , Focal Adhesion Protein-Tyrosine Kinases/chemistry , Focal Adhesion Protein-Tyrosine Kinases/metabolism , Humans , Allosteric Site , Protein Binding , Drug Design , Binding Sites , Pharmacophore
7.
Sci Rep ; 14(1): 11575, 2024 05 21.
Article in English | MEDLINE | ID: mdl-38773273

ABSTRACT

Leishmaniasis is a disease caused by a protozoan of the genus Leishmania, affecting millions of people, mainly in tropical countries, due to poor social conditions and low economic development. First-line chemotherapeutic agents involve highly toxic pentavalent antimonials, while treatment failure is mainly due to the emergence of drug-resistant strains. Leishmania arginase (ARG) enzyme is vital in pathogenicity and contributes to a higher infection rate, thus representing a potential drug target. This study helps in designing ARG inhibitors for the treatment of leishmaniasis. Py-CoMFA (3D-QSAR) models were constructed using 34 inhibitors from different chemical classes against ARG from L. (L.) amazonensis (LaARG). The 3D-QSAR predictions showed an excellent correlation between experimental and calculated pIC50 values. The molecular docking study identified the favorable hydrophobicity contribution of phenyl and cyclohexyl groups as substituents in the enzyme allosteric site. Molecular dynamics simulations of selected protein-ligand complexes were conducted to understand derivatives' interaction modes and affinity in both active and allosteric sites. Two cinnamide compounds, 7g and 7k, were identified, with similar structures to the reference 4h allosteric site inhibitor. These compounds can guide the development of more effective arginase inhibitors as potential antileishmanial drugs.


Subject(s)
Arginase , Enzyme Inhibitors , Leishmania , Molecular Docking Simulation , Molecular Dynamics Simulation , Arginase/antagonists & inhibitors , Arginase/chemistry , Arginase/metabolism , Leishmania/enzymology , Leishmania/drug effects , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Quantitative Structure-Activity Relationship , Protozoan Proteins/antagonists & inhibitors , Protozoan Proteins/chemistry , Protozoan Proteins/metabolism , Allosteric Site , Antiprotozoal Agents/pharmacology , Antiprotozoal Agents/chemistry , Catalytic Domain
8.
Molecules ; 29(9)2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38731442

ABSTRACT

Two series, "a" and "b", each consisting of nine chemical compounds, with 2,3-disubstituted quinazolin-4(3H)-one scaffold, were synthesized and evaluated for their anticonvulsant activity. They were investigated as dual potential positive allosteric modulators of the GABAA receptor at the benzodiazepine binding site and inhibitors of carbonic anhydrase II. Quinazolin-4(3H)-one derivatives were evaluated in vivo (D1-3 = 50, 100, 150 mg/kg, administered intraperitoneally) using the pentylenetetrazole (PTZ)-induced seizure model in mice, with phenobarbital and diazepam, as reference anticonvulsant agents. The in silico studies suggested the compounds act as anticonvulsants by binding on the allosteric site of GABAA receptor and not by inhibiting the carbonic anhydrase II, because the ligands-carbonic anhydrase II predicted complexes were unstable in the molecular dynamics simulations. The mechanism targeting GABAA receptor was confirmed through the in vivo flumazenil antagonism assay. The pentylenetetrazole experimental anticonvulsant model indicated that the tested compounds, 1a-9a and 1b-9b, present a potential anticonvulsant activity. The evaluation, considering the percentage of protection against PTZ, latency until the onset of the first seizure, and reduction in the number of seizures, revealed more favorable results for the "b" series, particularly for compound 8b.


Subject(s)
Anticonvulsants , Pentylenetetrazole , Receptors, GABA-A , Seizures , Anticonvulsants/pharmacology , Anticonvulsants/chemical synthesis , Anticonvulsants/chemistry , Animals , Mice , Seizures/drug therapy , Seizures/chemically induced , Receptors, GABA-A/metabolism , Quinazolinones/pharmacology , Quinazolinones/chemistry , Quinazolinones/chemical synthesis , Molecular Docking Simulation , Male , Structure-Activity Relationship , Molecular Dynamics Simulation , Computer Simulation , Disease Models, Animal , Molecular Structure , Allosteric Site
9.
Signal Transduct Target Ther ; 9(1): 88, 2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38594257

ABSTRACT

G protein-coupled receptors (GPCRs), the largest family of human membrane proteins and an important class of drug targets, play a role in maintaining numerous physiological processes. Agonist or antagonist, orthosteric effects or allosteric effects, and biased signaling or balanced signaling, characterize the complexity of GPCR dynamic features. In this study, we first review the structural advancements, activation mechanisms, and functional diversity of GPCRs. We then focus on GPCR drug discovery by revealing the detailed drug-target interactions and the underlying mechanisms of orthosteric drugs approved by the US Food and Drug Administration in the past five years. Particularly, an up-to-date analysis is performed on available GPCR structures complexed with synthetic small-molecule allosteric modulators to elucidate key receptor-ligand interactions and allosteric mechanisms. Finally, we highlight how the widespread GPCR-druggable allosteric sites can guide structure- or mechanism-based drug design and propose prospects of designing bitopic ligands for the future therapeutic potential of targeting this receptor family.


Subject(s)
Drug Discovery , Receptors, G-Protein-Coupled , United States , Humans , Receptors, G-Protein-Coupled/chemistry , Allosteric Site , Drug Design , Ligands
10.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 41(2): 313-320, 2024 Apr 25.
Article in Chinese | MEDLINE | ID: mdl-38686412

ABSTRACT

Targeting p21-activated kinase 1 (PAK1) is a novel strategy for pancreatic cancer treatment. Compound Kushen injection contains many anti-pancreatic cancer components, but the specific targets are unknown. In this study, 14α-hydroxymatrine, an active component of Kushen injection, was found to possess high binding free energy with the allosteric site of PAK1 by molecular docking based virtual screening. Molecular dynamics simulations suggested that 14α-hydroxymatrine caused the α1 and α2 helices of the allosteric site of PAK1 to extend outward to form a deep allosteric regulatory pocket. Meanwhile, 14α-hydroxymatrine induced the ß-folding region at the adenosine triphosphate (ATP)-binding pocket of PAK1 to close inward, resulting in the ATP-binding pocket in a "semi-closed" state which caused the inactivation of PAK1. After removal of 14α-hydroxymatrine, PAK1 showed a tendency to change from the inactive conformation to the active conformation. We supposed that 14α-hydroxymatrine of compound Kushen injection might be a reversible allosteric inhibitor of PAK1. This study used modern technologies and methods to study the active components of traditional Chinese medicine, which laid a foundation for the development and utilization of natural products and the search for new treatments for pancreatic cancer.


Subject(s)
Molecular Docking Simulation , Molecular Dynamics Simulation , p21-Activated Kinases , p21-Activated Kinases/metabolism , p21-Activated Kinases/antagonists & inhibitors , Humans , Allosteric Site , Pancreatic Neoplasms/drug therapy , Drugs, Chinese Herbal/pharmacology , Drugs, Chinese Herbal/chemistry , Quinolizines/pharmacology , Quinolizines/chemistry
11.
Nature ; 628(8008): 664-671, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38600377

ABSTRACT

Bitter taste sensing is mediated by type 2 taste receptors (TAS2Rs (also known as T2Rs)), which represent a distinct class of G-protein-coupled receptors1. Among the 26 members of the TAS2Rs, TAS2R14 is highly expressed in extraoral tissues and mediates the responses to more than 100 structurally diverse tastants2-6, although the molecular mechanisms for recognizing diverse chemicals and initiating cellular signalling are still poorly understood. Here we report two cryo-electron microscopy structures for TAS2R14 complexed with Ggust (also known as gustducin) and Gi1. Both structures have an orthosteric binding pocket occupied by endogenous cholesterol as well as an intracellular allosteric site bound by the bitter tastant cmpd28.1, including a direct interaction with the α5 helix of Ggust and Gi1. Computational and biochemical studies validate both ligand interactions. Our functional analysis identified cholesterol as an orthosteric agonist and the bitter tastant cmpd28.1 as a positive allosteric modulator with direct agonist activity at TAS2R14. Moreover, the orthosteric pocket is connected to the allosteric site via an elongated cavity, which has a hydrophobic core rich in aromatic residues. Our findings provide insights into the ligand recognition of bitter taste receptors and suggest activities of TAS2R14 beyond bitter taste perception via intracellular allosteric tastants.


Subject(s)
Cholesterol , Intracellular Space , Receptors, G-Protein-Coupled , Taste , Humans , Allosteric Regulation/drug effects , Allosteric Site , Cholesterol/chemistry , Cholesterol/metabolism , Cholesterol/pharmacology , Cryoelectron Microscopy , Hydrophobic and Hydrophilic Interactions , Intracellular Space/chemistry , Intracellular Space/metabolism , Ligands , Receptors, G-Protein-Coupled/agonists , Receptors, G-Protein-Coupled/chemistry , Receptors, G-Protein-Coupled/metabolism , Receptors, G-Protein-Coupled/ultrastructure , Reproducibility of Results , Taste/drug effects , Taste/physiology , Transducin/chemistry , Transducin/metabolism , Transducin/ultrastructure
12.
Bioorg Chem ; 147: 107317, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38583252

ABSTRACT

By inducing steric activation of the 10CH bond with a 12-acyl group to form a key imine oxime intermediate, 20 novel (10S)-10,12-disubstituted aloperine derivatives were successfully synthesized and assessed for their antiviral efficacy against HCoV-OC43. Of them, compound 3i exhibited the moderate activities against HCoV-OC43, as well as against the SARS-CoV-2 variant EG.5.1 with the comparable EC50 values of 4.7 and 4.1 µM. A mechanism study revealed that it inhibited the protease activity of host TMPRSS2 by binding to an allosteric site, rather than the known catalytic center, different from that of camostat. Also, the combination of compound 3i and molnupiravir, as an RdRp inhibitor, showed an additive antiviral effect against HCoV-OC43. The results provide a new binding mode and lead compound for targeting TMPRSS2, with an advantage in combating broad-spectrum coronavirus.


Subject(s)
Allosteric Site , Antiviral Agents , Coronavirus OC43, Human , Quinolizidines , Serine Endopeptidases , Antiviral Agents/pharmacology , Antiviral Agents/chemistry , Antiviral Agents/chemical synthesis , Serine Endopeptidases/metabolism , Humans , Coronavirus OC43, Human/drug effects , Coronavirus OC43, Human/chemistry , Quinolizidines/chemistry , Quinolizidines/pharmacology , Quinolizidines/chemical synthesis , Allosteric Site/drug effects , Structure-Activity Relationship , Drug Discovery , SARS-CoV-2/drug effects , Molecular Structure , Microbial Sensitivity Tests , Dose-Response Relationship, Drug
13.
J Phys Chem B ; 128(21): 5157-5174, 2024 May 30.
Article in English | MEDLINE | ID: mdl-38647430

ABSTRACT

The chemokine receptor CXCR4 is a critical target for the treatment of several cancer types and HIV-1 infections. While orthosteric and allosteric modulators have been developed targeting its extracellular or transmembrane regions, the intramembrane region of CXCR4 may also include allosteric binding sites suitable for the development of allosteric drugs. To investigate this, we apply the Gaussian Network Model (GNM) to the monomeric and dimeric forms of CXCR4 to identify residues essential for its local and global motions located in the hinge regions of the protein. Residue interaction network (RIN) analysis suggests hub residues that participate in allosteric communication throughout the receptor. Mutual residues from the network models reside in regions with a high capacity to alter receptor dynamics upon ligand binding. We then investigate the druggability of these potential allosteric regions using the site identification by ligand competitive saturation (SILCS) approach, revealing two putative allosteric sites on the monomer and three on the homodimer. Two screening campaigns with Glide and SILCS-Monte Carlo docking using FDA-approved drugs suggest 20 putative hit compounds including antifungal drugs, anticancer agents, HIV protease inhibitors, and antimalarial drugs. In vitro assays considering mAB 12G5 and CXCL12 demonstrate both positive and negative allosteric activities of these compounds, supporting our computational approach. However, in vivo functional assays based on the recruitment of ß-arrestin to CXCR4 do not show significant agonism and antagonism at a single compound concentration. The present computational pipeline brings a new perspective to computer-aided drug design by combining conformational dynamics based on network analysis and cosolvent analysis based on the SILCS technology to identify putative allosteric binding sites using CXCR4 as a showcase.


Subject(s)
Allosteric Site , Receptors, CXCR4 , Receptors, CXCR4/chemistry , Receptors, CXCR4/metabolism , Receptors, CXCR4/antagonists & inhibitors , Ligands , Humans , Molecular Docking Simulation , Monte Carlo Method , Allosteric Regulation
14.
J Chem Inf Model ; 64(6): 2058-2067, 2024 Mar 25.
Article in English | MEDLINE | ID: mdl-38457234

ABSTRACT

The biochemical basis for substrate dependences in apparent inhibition constant values (Ki) remains unknown. Our study aims to elucidate plausible structural determinants underpinning these observations. In vitro steady-state inhibition assays conducted using human recombinant CYP3A4 enzyme and testosterone substrate revealed that fibroblast growth factor receptor (FGFR) inhibitors erdafitinib and pemigatinib noncompetitively inhibited CYP3A4 with apparent Ki values of 10.2 ± 1.1 and 3.3 ± 0.9 µM, respectively. However, when rivaroxaban was adopted as the probe substrate, there were 2.0- and 3.2-fold decreases in its apparent Ki values. To glean mechanistic insights into this phenomenon, erdafitinib and pemigatinib were docked to allosteric sites in CYP3A4. Subsequently, molecular dynamics (MD) simulations of apo- and holo-CYP3A4 were conducted to investigate the structural changes induced. Comparative structural analyses of representative MD frames extracted by hierarchical clustering revealed that the allosteric inhibition of CYP3A4 by erdafitinib and pemigatinib did not substantially modulate its active site characteristics. In contrast, we discovered that allosteric binding of the FGFR inhibitors reduces the structural flexibility of the F-F' loop region, an important gating mechanism to regulate access of the substrate to the catalytic heme. We surmised that the increased rigidity of the F-F' loop engenders a more constrained entrance to the CYP3A4 active site, which in turn impedes access to the larger rivaroxaban molecule to a greater extent than testosterone and culminates in more potent inhibition of its CYP3A4-mediated metabolism. Our findings suggest a potential mechanism to rationalize probe substrate dependencies in Ki arising from the allosteric noncompetitive inhibition of CYP3A4.


Subject(s)
Cytochrome P-450 CYP3A , Rivaroxaban , Humans , Cytochrome P-450 CYP3A/metabolism , Allosteric Site , Molecular Dynamics Simulation , Testosterone/metabolism
15.
J Med Chem ; 67(6): 4655-4675, 2024 Mar 28.
Article in English | MEDLINE | ID: mdl-38462716

ABSTRACT

The ubiquitously expressed protein tyrosine phosphatase SHP2 is required for signaling downstream of receptor tyrosine kinases (RTKs) and plays a role in regulating many cellular processes. Genetic knockdown and pharmacological inhibition of SHP2 suppresses RAS/MAPK signaling and inhibit the proliferation of RTK-driven cancer cell lines. Here, we describe the first reported fragment-to-lead campaign against SHP2, where X-ray crystallography and biophysical techniques were used to identify fragments binding to multiple sites on SHP2. Structure-guided optimization, including several computational methods, led to the discovery of two structurally distinct series of SHP2 inhibitors binding to the previously reported allosteric tunnel binding site (Tunnel Site). One of these series was advanced to a low-nanomolar lead that inhibited tumor growth when dosed orally to mice bearing HCC827 xenografts. Furthermore, a third series of SHP2 inhibitors was discovered binding to a previously unreported site, lying at the interface of the C-terminal SH2 and catalytic domains.


Subject(s)
Neoplasms , Protein Tyrosine Phosphatase, Non-Receptor Type 11 , Humans , Mice , Animals , Signal Transduction , Receptor Protein-Tyrosine Kinases/metabolism , Allosteric Site
16.
Bioorg Med Chem Lett ; 103: 129690, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38447786

ABSTRACT

Autotaxin is a secreted lysophospholipase D which is a member of the ectonucleotide pyrophosphatase/phosphodiesterase family converting extracellular lysophosphatidylcholine and other non-choline lysophospholipids, such as lysophosphatidylethanolamine and lysophosphatidylserine, to the lipid mediator lysophosphatidic acid. Autotaxin is implicated in various fibroproliferative diseases including interstitial lung diseases, such as idiopathic pulmonary fibrosis and hepatic fibrosis, as well as in cancer. In this study, we present an effort of identifying ATX inhibitors that bind to allosteric ATX binding sites using the Enalos Asclepios KNIME Node. All the available PDB crystal structures of ATX were collected, prepared, and aligned. Visual examination of these structures led to the identification of four crystal structures of human ATX co-crystallized with four known inhibitors. These inhibitors bind to five binding sites with five different binding modes. These five binding sites were thereafter used to virtually screen a compound library of 14,000 compounds to identify molecules that bind to allosteric sites. Based on the binding mode and interactions, the docking score, and the frequency that a compound comes up as a top-ranked among the five binding sites, 24 compounds were selected for in vitro testing. Finally, two compounds emerged with inhibitory activity against ATX in the low micromolar range, while their mode of inhibition and binding pattern were also studied. The two derivatives identified herein can serve as "hits" towards developing novel classes of ATX allosteric inhibitors.


Subject(s)
Lysophospholipids , Neoplasms , Humans , Lysophospholipids/chemistry , Lysophospholipids/metabolism , Phosphoric Diester Hydrolases/metabolism , Neoplasms/metabolism , Binding Sites , Allosteric Site
17.
Comput Biol Med ; 173: 108283, 2024 May.
Article in English | MEDLINE | ID: mdl-38552278

ABSTRACT

Allosteric drugs hold the promise of addressing many challenges in the current drug development of GPCRs. However, the molecular mechanism underlying their allosteric modulations remain largely elusive. The dopamine D1 receptor (DRD1), a member of Class A GPCRs, is critical for treating psychiatric disorders, and LY3154207 serves as its promising positive allosteric modulator (PAM). In the work, we utilized extensive Gaussian-accelerated molecular dynamics simulations (a total of 41µs) for the first time probe the diverse binding modes of the allosteric modulator and their regulation effects, based on the DRD1 and LY3154207 as representative. Our simulations identify four binding modes of LY3154207 (one boat mode, two metastable vertical modes and a novel cleft-anchored mode), in which the boat mode is the most stable while there three modes are similar in the stability. However, it is interesting to observed that the most stable boat mode inversely exhibits the weakest positive allosteric effect on influencing the orthosteric ligand binding and maintaining the activity of the transducer binding site. It should result from its induced weaker correlation between the allosteric site and the orthosteric site, and between the orthosteric site and the transducer binding site than the other three binding modes, as well as its weakened interaction between a crucial activation-related residue (S2025.46) and the orthosteric ligand (dopamine). Overall, the work offers atomic-level information to advance our understanding of the complex allosteric regulation on GPCRs, which is beneficial to the allosteric modulator design and development.


Subject(s)
Receptors, Dopamine D1 , Humans , Allosteric Regulation/physiology , Allosteric Site , Binding Sites , Ligands , Receptors, Dopamine D1/chemistry , Receptors, Dopamine D1/metabolism
18.
Curr Opin Struct Biol ; 86: 102792, 2024 06.
Article in English | MEDLINE | ID: mdl-38428364

ABSTRACT

Allostery is a fundamental mechanism of cellular homeostasis by intra-protein communication between distinct functional sites. It is an internal process of proteins to steer interactions not only with each other but also with other biomolecules such as ligands, lipids, and nucleic acids. In addition, allosteric regulation is particularly important in enzymatic activities. A major challenge in structural and molecular biology today is unraveling allosteric sites in proteins, to elucidate the detailed mechanism of allostery and the development of allosteric drugs. Here we summarize the recently developed tools and approaches which enable the elucidation of regulatory hotspots and correlated motion in biomolecules, focusing primarily on solution-state nuclear magnetic resonance spectroscopy (NMR). These tools open an avenue towards a rational understanding of the mechanism of allostery and provide essential information for the design of allosteric drugs.


Subject(s)
Nuclear Magnetic Resonance, Biomolecular , Proteins , Allosteric Regulation , Proteins/chemistry , Proteins/metabolism , Nuclear Magnetic Resonance, Biomolecular/methods , Allosteric Site , Humans , Magnetic Resonance Spectroscopy/methods , Protein Conformation , Models, Molecular
19.
Curr Opin Struct Biol ; 86: 102793, 2024 06.
Article in English | MEDLINE | ID: mdl-38447285

ABSTRACT

Protein-ligand binding site prediction is critical for protein function annotation and drug discovery. Biological experiments are time-consuming and require significant equipment, materials, and labor resources. Developing accurate and efficient computational methods for protein-ligand interaction prediction is essential. Here, we summarize the key challenges associated with ligand binding site (LBS) prediction and introduce recently published methods from their input features, computational algorithms, and ligand types. Furthermore, we investigate the specificity of allosteric site identification as a particular LBS type. Finally, we discuss the prospective directions for machine learning-based LBS prediction in the near future.


Subject(s)
Protein Binding , Proteins , Ligands , Binding Sites , Proteins/chemistry , Proteins/metabolism , Computational Biology/methods , Machine Learning , Algorithms , Allosteric Site , Humans
20.
Proteins ; 92(7): 865-873, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38459426

ABSTRACT

The receptor binding domain (RBD) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein must undergo a crucial conformational transition to invade human cells. It is intriguing that this transition is accompanied by a synchronized movement of the entire spike protein. Therefore, it is possible to design allosteric regulators targeting non-RBD but hindering the conformational transition of RBD. To understand the allosteric mechanism in detail, we establish a computational framework by integrating coarse-grained molecular dynamic simulations and a state-of-the-art neural network model called neural relational inference. Leveraging this framework, we have elucidated the allosteric pathway of the SARS-CoV-2 spike protein at the residue level and identified the molecular mechanisms involved in the transmission of allosteric signals. The movement of D614 is coupled with that of Q321. This interaction subsequently influences the movement of K528/K529, ultimately coupling with the movement of RBD during conformational changes. Mutations that weaken the interactions within this pathway naturally block the allosteric signal transmission, thereby modulating the conformational transitions. This observation also offers a rationale for the distinct allosteric patterns observed in the SARS-CoV spike protein. Our result provides a useful method for analyzing the dynamics of potential viral variants in the future.


Subject(s)
Molecular Dynamics Simulation , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Humans , SARS-CoV-2/chemistry , SARS-CoV-2/metabolism , Allosteric Regulation , Protein Binding , Neural Networks, Computer , COVID-19/virology , COVID-19/metabolism , Mutation , Protein Conformation , Binding Sites , Allosteric Site
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