RESUMO
Glycation of proteins leading to the formation of advanced glycation end products (AGEs) has been demonstrated to contribute to the pathogenesis of several diseases. Irisin is a clinically significant protein, putatively involved in obesity, diabetes, and neurological disorders. This study aimed to monitor the methyl-glyoxal (MG) induced AGEs and aggregate formation of irisin, as a function of time, employing multispectroscopic and microscopic approaches. ANS fluorescence suggested a molten globule-like state on Day 6, followed by the formation of irisin AGEs adducts, as confirmed by AGE-specific fluorescence. Glycation of irisin led to aggregate formation, which was characterized by Thioflavin T fluorescence, CD spectroscopy, and microscopic studies. These aggregates were confirmed by exploiting fluorescence microscopy, confocal, and transmission electron microscopy. Molecular docking was performed to determine the crucial residues of irisin involved in irisin-MG interaction. Usually, MG is present in trace amounts as a metabolic by-product in the body, which is found to be elevated in diseased conditions viz. diabetes and Alzheimer's disease. This study characterized the AGEs and aggregates of clinically important protein, irisin; and since MG level has been found to be increased in various pathological conditions, this study provides a clinical perspective. There is a possibility that elevated MG concentrations might glycate irisin resulting in reduced irisin levels as reported in pathological conditions. However, further investigations are required to prove it.
Assuntos
Diabetes Mellitus , Produtos Finais de Glicação Avançada , Humanos , Fibronectinas , Produtos Finais de Glicação Avançada/metabolismo , Simulação de Acoplamento Molecular , Aldeído Pirúvico/farmacologiaRESUMO
Microtubule affinity-regulating kinase 4 (MARK4) is a member of the Ser/Thr protein kinase family, phosphorylates the microtubule-connected proteins and plays a vital role in causing cancers and neurodegenerative diseases. This kinase modulates multiple signaling pathways, including mammalian target of rapamycin, nuclear factor-κB, and Hippo-signaling, presumably responsible for cancer and Alzheimer's. MARK4 acts as a negative controller of the Hippo-kinase cassette for promoting YAP/TAZ action, and the loss of MARK4 detains the tumorigenic properties of cancer cells. MARK4 is involved in tau hyperphosphorylation that consequently affects neurodegeneration. MARK4 is a promising drug target for cancer, diabetes, and Alzheimer's. Developing the potent and selective inhibitors of MAKR4 are promising in the therapeutic management of associated diseases. Despite its great significance, a few reviews are available to discuss its structure, function and clinical significance. In the current review, we aimed to provide detailed information on the structural features of MARK4 targeted in drug development and its role in various signaling pathways related to cancer and neurodegenerative diseases. We further described the therapeutic potential of MARK4 inhibitors in preventing numerous diseases. Finally, the updated information on MARK4 will be helpful in the further development of effective therapeutic molecules.
Assuntos
Doença de Alzheimer , Neoplasias , Doenças Neurodegenerativas , Humanos , Doenças Neurodegenerativas/tratamento farmacológico , Doença de Alzheimer/tratamento farmacológico , Neoplasias/tratamento farmacológico , Carcinogênese , Proteínas dos Microtúbulos , MicrotúbulosRESUMO
Huntington's disease (HD) is an autosomal dominant ailment that affects a larger population. Due to its complex pathology operating at DNA, RNA, and protein levels, it is regarded as a protein-misfolding disease and an expansion repeat disorder. Despite the availability of early genetic diagnostics, disease-modifying treatments are still missing. Importantly, potential therapies are starting to make their way through clinical trials. Still, clinical trials are ongoing to discover potential drugs to relieve HD symptoms. However, now being aware of the root cause, the clinical studies are focused on molecular therapies to target it. The road to success has not been without bumps since a big phase III trial of tominersen was unexpectedly discontinued due to exceeding risks than drug's benefit to the patients. Although the trial's conclusion was disappointing, there is still cause to be optimistic about what this technique may achieve. We have reviewed the present disease-modifying therapies in clinical development for HD and examined the current landscape of developing clinical therapies. We further investigated the pharmaceutical development of Huntington's medicine in the pharma industries and addressed the existing challenges in their therapeutic success.
Assuntos
Doença de Huntington , Humanos , Doença de Huntington/tratamento farmacológico , Doença de Huntington/genética , RNA , DNA , Desenvolvimento de Medicamentos , Proteína Huntingtina/genética , Proteína Huntingtina/metabolismoRESUMO
Curcumin is a natural anti-inflammatory and antioxidant substance which plays a major role in reducing the amyloid plaques formation, which is the major cause of Alzheimer's disease (AD). Consequently, a methodical approach was used to select the potential protein targets of curcumin in AD through network pharmacology. In this study, through integrative methods, AD targets of curcumin through SwissTargetPrediction database, STITCH database, BindingDB, PharmMapper, Therapeutic Target Database (TTD), Online Mendelian Inheritance in Man (OMIM) database were predicted followed by gene enrichment analysis, network construction, network topology, and docking studies. Gene ontology analysis facilitated identification of a list of possible AD targets of curcumin (74 targets genes). The correlation of the obtained targets with AD was analysed by using gene ontology (GO) pathway enrichment analyses and Kyoto Encyclopaedia of Genes and Genomes (KEGG). We have incorporated the applied network pharmacological approach to identify key genes. Furthermore, we have performed molecular docking for analysing the mechanism of curcumin. In order to validate the temporospatial expression of key genes in human central nervous system (CNS), we searched the Human Brain Transcriptome (HBT) dataset. We identified top five key genes namely, PPARγ, MAPK1, STAT3, KDR and APP. Further validated the expression profiling of these key genes in publicly available brain data expression profile databases. In context to a valuable addition in the treatment of AD, this study is concluded with novel insights into the therapeutic mechanisms of curcumin, will ease the treatment of AD with the clinical application of curcumin.
Assuntos
Doença de Alzheimer , Curcumina , Humanos , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/genética , Curcumina/farmacologia , Curcumina/uso terapêutico , Simulação de Acoplamento Molecular , Farmacologia em Rede , Biologia Computacional , Bases de Dados GenéticasRESUMO
Laccase, one of the metalloproteins, belongs to the multicopper oxidase family. It oxidizes a wide range of substrates and generates water as a sole by-product. The engineering of laccase is important to broaden their industrial and environmental applications. The general assumption is that the low redox potential of laccases is the principal obstacle, as evidenced by their low activity towards certain substrates. Therefore, the primary goal of engineering laccases is to improve their oxidation capability, thereby increasing their redox potential. Even though some of the determinants of laccase are known, it is still not entirely clear how to enhance its redox potential. However, the laccase active site has additional characteristics that regulate the enzymes' activity and specificity. These include the electrostatic and hydrophobic environment of the substrate binding pocket, the steric effect at the substrate binding site, and the orientation of the binding substrate with respect to the T1 site of the laccase. In this review, these features of the substrate binding site will be discussed to highlight their importance as a target for future laccase engineering.
Assuntos
Lacase , Metaloproteínas , Lacase/genética , Sítios de Ligação , Engenharia , IndústriasRESUMO
Identifying novel molecules as potential kinase inhibitors are gaining significant attention globally. The present study suggests Myricetin as a potential inhibitor of microtubule-affinity regulating kinase (MARK4), adding another molecule to the existing list of anticancer therapeutics. MARK4 regulates initial cell division steps and is a potent druggable target for various cancers. Structure-based docking with 100 ns molecular dynamics simulation depicted activity of Myricetin in the active site pocket of MARK4 and the formation of a stable complex. The fluorescence-based assay showed excellent affinity of Myricetin to MARK4 guided by static and dynamic quenching. Moreover, the assessment of enthalpy change (∆H) and entropy change (∆S) delineated electrostatic interactions as a dominant force in the MARK4-myricetin interaction. Isothermal titration calorimetric measurements revealed spontaneous binding of Myricetin with MARK4. Further, the kinase assay depicted significant inhibition of MARK4 by Myricetin with IC50 = 3.11 µM. Additionally, cell proliferation studies established that Myricetin significantly inhibited the cancer cells (MCF-7 and A549) proliferation, and inducing apoptosis. This study provides a solid rationale for developing Myricetin as a promising anticancer molecule in the MARK4 mediated malignancies.
Assuntos
Neoplasias da Mama , Flavonoides , Neoplasias Pulmonares , Proteínas de Neoplasias , Células A549 , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/enzimologia , Feminino , Flavonoides/química , Flavonoides/farmacologia , Células HEK293 , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/enzimologia , Células MCF-7 , Proteínas de Neoplasias/antagonistas & inibidores , Proteínas de Neoplasias/química , Proteínas de Neoplasias/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/metabolismoRESUMO
Iron deposition in the central nervous system (CNS) is one of the causes of neurodegenerative diseases. Human transferrin (hTf) acts as an iron carrier present in the blood plasma, preventing it from contributing to redox reactions. Plant compounds and their derivatives are frequently being used in preventing or delaying Alzheimer's disease (AD). Thymoquinone (TQ), a natural product has gained popularity because of its broad therapeutic applications. TQ is one of the significant phytoconstituent of Nigella sativa. The binding of TQ to hTf was determined by spectroscopic methods and isothermal titration calorimetry. We have observed that TQ strongly binds to hTf with a binding constant (K) of 0.22 × 106 M-1 and forming a stable complex. In addition, isothermal titration calorimetry revealed the spontaneous binding of TQ with hTf. Molecular docking analysis showed key residues of the hTf that were involved in the binding to TQ. We further performed a 250 ns molecular dynamics simulation which deciphered the dynamics and stability of the hTf-TQ complex. Structure analysis suggested that the binding of TQ doesn't cause any significant alterations in the hTf structure during the course of simulation and a stable complex is formed. Altogether, we have elucidated the mechanism of binding of TQ with hTf, which can be further implicated in the development of a novel strategy for AD therapy.
Assuntos
Doença de Alzheimer , Transferrina , Doença de Alzheimer/tratamento farmacológico , Benzoquinonas , Humanos , Ferro/metabolismo , Simulação de Acoplamento Molecular , Transferrina/química , Transferrina/metabolismoRESUMO
The prevalence of Alzheimer's disease (AD) has been a major health concern for a long time. Despite recent progress, there is still a strong need to develop effective disease-modifying therapies. Several drugs have already been approved to retard the progression of AD-related symptoms; however, there is a need to develop an effective carrier system for the delivery of drugs to combat such diseases. In recent years, various biological macromolecules, including proteins, have been used as carriers for drug delivery. Irisin is a beneficial hormone in such diseases, including AD and related pathologies. Herein, the interaction mechanism of irisin with AD drugs such as memantine, galantamine, and fluoxetine is investigated. Fluorescence studies revealed that the above drugs bind to irisin with significant affinity, with fluoxetine having the highest binding affinity. Isothermal titration calorimetry (ITC) complemented the spontaneous binding of these drugs with irisin, delineating various associated thermodynamic and binding parameters. Molecular docking further validated the fluorescence and ITC results and unfolded the mechanism that hydrogen bonding governs the binding of fluoxetine to irisin with a significant binding score, i.e., -6.3 kcal/mol. We believe that these findings provide a promising solution to fight against AD as well as a platform for further research to utilize irisin in the drug-delivery system for an effective therapeutic strategy.
Assuntos
Doença de Alzheimer , Fibronectinas , Doença de Alzheimer/tratamento farmacológico , Sítios de Ligação , Calorimetria/métodos , Fluoxetina , Humanos , Simulação de Acoplamento Molecular , Preparações Farmacêuticas , Ligação Proteica , Espectrometria de Fluorescência , TermodinâmicaRESUMO
Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infection in children and infants. To date, there is no effective vaccine available against RSV. Heparan sulfate is a type of glycosaminoglycan that aids in the attachment of the RSV to the host cell membrane via the G protein. In the present study, the effect of amino acid substitution on the structure and stability of the ectodomain G protein was studied. Further, it was investigated whether mutation (K117A) in the CX3C motif of G protein alters the binding with heparan sulfate. The point mutation significantly affects the conformational stability of the G protein. The mutant protein showed a low binding affinity with heparan sulfate as compared to the wild-type G protein, as determined by fluorescence quenching, isothermal titration calorimetry (ITC), and molecular docking studies. The low binding affinity and decreased stability suggested that this mutation may play an important role in prevention of attachment of virion to the host cell receptors. Collectively, this investigation suggests that mutation in the CX3C motif of G protein may likely improve the efficacy and safety of the RSV vaccine.
Assuntos
Receptor 1 de Quimiocina CX3C/genética , Receptor 1 de Quimiocina CX3C/metabolismo , Proteínas de Ligação ao GTP/genética , Proteínas de Ligação ao GTP/metabolismo , Heparitina Sulfato/metabolismo , Mutação/genética , Substituição de Aminoácidos/genética , Calorimetria/métodos , Linhagem Celular , Humanos , Simulação de Acoplamento Molecular/métodos , Receptores de Quimiocinas/genética , Receptores de Quimiocinas/metabolismo , Infecções por Vírus Respiratório Sincicial/metabolismo , Vírus Sincicial Respiratório Humano/metabolismo , Análise Espectral/métodos , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo , Vírion/genética , Replicação Viral/genéticaRESUMO
A sedentary lifestyle or lack of physical activity increases the risk of different diseases, including obesity, diabetes, heart diseases, certain types of cancers, and some neurological diseases. Physical exercise helps improve quality of life and reduces the risk of many diseases. Irisin, a hormone induced by exercise, is a fragmented product of FNDC5 (a cell membrane protein) and acts as a linkage between muscles and other tissues. Over the past decade, it has become clear that irisin is a molecular mimic of exercise and shows various beneficial effects, such as browning of adipocytes, modulation of metabolic processes, regulation of bone metabolism, and functioning of the nervous system. Irisin has a role in carcinogenesis; numerous studies have shown its impact on migration, invasion, and proliferation of cancer cells. The receptor of irisin is not completely known; however, in some tissues it probably acts via a specific class of integrin receptors. Here, we review research from the past decade that has identified irisin as a potential therapeutic agent in the prevention or treatment of various metabolic-related and other diseases. This article delineates structural and biochemical aspects of irisin and provides an insight into the role of irisin in different pathological conditions.
Assuntos
Fibronectinas/metabolismo , Doenças Metabólicas/metabolismo , Neoplasias/metabolismo , Animais , Carcinogênese/metabolismo , Exercício Físico , Fibronectinas/análise , Humanos , Doenças Metabólicas/fisiopatologia , Modelos Moleculares , Neoplasias/fisiopatologia , Conformação Proteica , Comportamento Sedentário , Transdução de SinaisRESUMO
This research work focuses on the potential application of an organic compound, santalol, obtained from santalum album, in the inhibition of the enzyme tyrosinase, which is actively involved in the biosynthesis of melanin pigment. Over-production of melanin causes undesirable pigmentation in humans as well as other organisms and significantly downgrades their aesthetic value. The study is designed to explain the purification of tyrosinase from the mushroom Agaricus bisporus, followed by activity assays and enzyme kinetics to give insight into the santalol-modulated tyrosinase inhibition in a dose-dependent manner. The multi-spectroscopic techniques such as UV-vis, fluorescence, and isothermal calorimetry are employed to deduce the efficiency of santalol as a potential candidate against tyrosinase enzyme activity. Experimental results are further verified by molecular docking. Santalol, derived from the essential oils of santalum album, has been widely used as a remedy for skin disorders and a potion for a fair complexion since ancient times. Based on enzyme kinetics and biophysical characterization, this is the first scientific evidence where santalol inhibits tyrosinase, and santalol may be employed in the agriculture, food, and cosmetic industries to prevent excess melanin formation or browning.
Assuntos
Melaninas , Monofenol Mono-Oxigenase , Humanos , Simulação de Acoplamento Molecular , Sesquiterpenos Policíclicos , Inibidores Enzimáticos/químicaRESUMO
Tank-binding kinase 1 (TBK1) is a serine/threonine protein kinase involved in various signaling pathways and subsequently regulates cell proliferation, apoptosis, autophagy, antiviral and antitumor immunity. Dysfunction of TBK1 can cause many complex diseases, including autoimmunity, neurodegeneration, and cancer. This dysfunction of TBK1 may result from single amino acid substitutions and subsequent structural alterations. This study analyzed the effect of substituting amino acids on TBK1 structure, function, and subsequent disease using advanced computational methods and various tools. In the initial assessment, a total of 467 mutations were found to be deleterious. After that, in detailed structural and sequential analyses, 13 mutations were found to be pathogenic. Finally, based on the functional importance, two variants (K38D and S172A) of the TBK1 kinase domain were selected and studied in detail by utilizing all-atom molecular dynamics (MD) simulation for 200 ns. MD simulation, including correlation matrix and principal component analysis, helps to get deeper insights into the TBK1 structure at the atomic level. We observed a substantial change in variants' conformation, which may be possible for structural alteration and subsequent TBK1 dysfunction. However, substitution S172A shows a significant conformational change in TBK1 structure as compared to K38D. Thus, this study provides a structural basis to understand the effect of mutations on the kinase domain of TBK1 and its function associated with disease progression.
Assuntos
Mutação , Proteínas Serina-Treonina Quinases/química , Sequência de Aminoácidos , Substituição de Aminoácidos , Humanos , Simulação de Dinâmica Molecular , Mutagênese Sítio-Dirigida , Conformação Proteica , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Homologia de SequênciaRESUMO
MAP/microtubule affinity-regulating kinase 4 (MARK4) is a member of serine/threonine kinase family and considered an attractive drug target for many diseases. Screening of Indian Medicinal Plants, Phytochemistry, and Therapeutics (IMPPAT) using virtual high-throughput screening coupled with enzyme assay suggested that Naringenin (NAG) could be a potent inhibitor of MARK4. Structure-based molecular docking analysis showed that NAG binds to the critical residues found in the active site pocket of MARK4. Furthermore, molecular dynamics (MD) simulation studies for 100 ns have delineated the binding mechanism of NAG to MARK4. Results of MD simulation suggested that binding of NAG further stabilizes the structure of MARK4 by forming a stable complex. In addition, no significant conformational change in the MARK4 structure was observed. Fluorescence binding and isothermal titration calorimetric measurements revealed an excellent binding affinity of NAG to MARK4 with a binding constant (K) = 0.13 × 106 M-1 obtained from fluorescence binding studies. Further, enzyme inhibition studies showed that NAG has an admirable IC50 value of 4.11 µM for MARK4. Together, these findings suggest that NAG could be an effective MARK4 inhibitor that can potentially be used to treat cancer and neurodegenerative diseases.
Assuntos
Flavanonas/química , Flavanonas/farmacologia , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/química , Sítios de Ligação , Antagonistas de Estrogênios/química , Antagonistas de Estrogênios/farmacologia , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Neoplasias/tratamento farmacológico , Doenças Neurodegenerativas/tratamento farmacológico , Ligação Proteica , Conformação ProteicaRESUMO
Hepatitis E virus (HEV) is a major causative agent of hepatitis E infections across the globe. Although the essentiality of HEV nonstructural polyprotein (pORF1) putative Y-domain (Yd) has been established in viral pathogenesis, its structural-functional role remains elusive. The current research discusses the novel exploration on Yd protein expression, purification, biophysical characterization and structure-based docking analysis. The codon optimized synthetic gene and optimized expression parameters i.e., 5 h induction with 0.25 mM IPTG at 37 °C, resulted in efficient production of Yd protein (~40 kDa) in E. coli BL21(DE3) cells. Majority of the recombinant Yd (rYd) protein expressed as inclusion bodies was solubilized in 0.5% N-lauroylsarcosine and purified using Ni-NTA chromatography. Circular dichroism (CD) and UV visible absorption spectroscopic studies on Yd revealed both secondary and tertiary structure stability in alkaline range (pH 8.0-10.0), suggesting correlation with its physiological activity. Thus, loss in structure at low pH perhaps play crucial role in cytoplasmic-membrane interaction. The biophysical data were in good agreement with insilico structural analyses, which suggested mixed α/ß fold, non-random and basic nature of Yd protein. Furthermore, due to Yd protein essentiality in HEV replication and pathogenesis, it was considered as a template for docking and drug-likeness analyses. The 3D modeling of Yd protein and structure-based screening and drug-likeness of inhibitory compounds, including established antiviral drugs led to the identification of top nine promising candidates. Nonetheless, in vitro studies on the predicted interaction of Yd with intracellular-membrane towards establishing replication-complexes as well as validations of the proposed therapeutic agents are warranted.
Assuntos
Vírus da Hepatite E/química , Proteínas Recombinantes/química , Proteínas Virais/química , Sequência de Aminoácidos , Domínio Catalítico , Escherichia coli/genética , Vírus da Hepatite E/genética , Humanos , Corpos de Inclusão/química , Simulação de Acoplamento Molecular , Conformação Proteica , Proteínas Recombinantes/genética , Solubilidade , Proteínas Virais/genéticaRESUMO
Ursolic acid (UA) is a pentacyclic triterpenoid frequently found in medicinal herbs and plants, having numerous pharmacological effects. UA and its analogs treat multiple diseases, including cancer, diabetic neuropathy, and inflammatory diseases. UA inhibits cancer proliferation, metastasis, angiogenesis, and induced cell death, scavenging free radicals and triggering numerous anti- and pro-apoptotic proteins. The biochemistry of UA has been examined broadly based on the literature, with alterations frequently having been prepared on positions C-3 (hydroxyl), C12-C13 (double bonds), and C-28 (carboxylic acid), leading to several UA derivatives with increased potency, bioavailability and water solubility. UA could be used as a protective agent to counter neural dysfunction via anti-oxidant and anti-inflammatory effects. It is a potential therapeutic drug implicated in the treatment of cancer and diabetic complications diseases provide novel machinery to the anti-inflammatory properties of UA. The pharmacological efficiency of UA is exhibited by the therapeutic theory of one-drug â several targets â one/multiple diseases. Hence, UA shows promising therapeutic potential for cancer and diabetic neuropathy diseases. This review aims to discuss mechanistic insights into promising beneficial effects of UA. We further explained the pharmacological aspects, clinical trials, and potential limitations of UA for the management of cancer and diabetic neuropathy diseases.
Assuntos
Anti-Inflamatórios/uso terapêutico , Antineoplásicos Fitogênicos/uso terapêutico , Neuropatias Diabéticas/tratamento farmacológico , Neoplasias/tratamento farmacológico , Plantas Medicinais/química , Triterpenos/uso terapêutico , Anti-Inflamatórios/química , Antineoplásicos Fitogênicos/química , Humanos , Triterpenos/química , Ácido UrsólicoRESUMO
Irisin is a clinically significant protein playing a valuable role in regulating various diseases. Irisin attenuates synaptic and memory dysfunction, highlighting its importance in Alzheimer's disease. On the other hand, Microtubule Affinity Regulating Kinase 4 (MARK4) is associated with various cancer types, uncontrolled neuronal migrations, and disrupted microtubule dynamics. In addition, MARK4 has been explored as a potential drug target for cancer and Alzheimer's disease therapy. Here, we studied the binding and subsequent inhibition of MARK4 by irisin. Irisin binds to MARK4 with an admirable affinity (K = 0.8 × 107 M-1), subsequently inhibiting its activity (IC50 = 2.71 µm). In vitro studies were further validated by docking and simulations. Molecular docking revealed several hydrogen bonds between irisin and MARK4, including critical residues, Lys38, Val40, and Ser134. Furthermore, the molecular dynamic simulation showed that the binding of irisin resulted in enhanced stability of MARK4. This study provides a rationale to use irisin as a therapeutic agent to treat MARK4-associated diseases.
Assuntos
Fibronectinas/metabolismo , Inibidores de Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Sítios de Ligação , Fibronectinas/química , Fibronectinas/uso terapêutico , Humanos , Ligação de Hidrogênio , Cinética , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Ligação Proteica , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Estabilidade ProteicaRESUMO
The global burden of disease caused by a respiratory syncytial virus (RSV) is becoming more widely recognized in young children and adults. Heparan sulfate helps in attaching the virion through G protein with the host cell membrane. In this study, we examined the structural changes of ectodomain G protein (edG) in a wide pH range. The absorbance results revealed that protein maintains its tertiary structure at physiological and highly acidic and alkaline pH. However, visible aggregation of protein was observed in mild acidic pH. The intrinsic fluorescence study shows no significant change in the λmax except at pH 12.0. The ANS fluorescence of edG at pH 2.0 and 3.0 forms an acid-induced molten globule-like state. The denaturation transition curve monitored by fluorescence spectroscopy revealed that urea and GdmCl induced denaturation native (N) â denatured (D) state follows a two-state process. The fluorescence quenching, molecular docking, and 50 ns simulation measurements suggested that heparan sulfate showed excellent binding affinity to edG. Our binding study provides a preliminary insight into the interaction of edG to the host cell membrane via heparan sulfate. This binding can be inhibited using experimental approaches at the molecular level leading to the prevention of effective host-pathogen interaction.
Assuntos
Domínio Catalítico , Heparitina Sulfato/metabolismo , Interações Hospedeiro-Patógeno , Simulação de Acoplamento Molecular/métodos , Vírus Sincicial Respiratório Humano/metabolismo , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/metabolismo , Membrana Celular/metabolismo , Humanos , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Agregados Proteicos , Agregação Patológica de Proteínas/metabolismo , Desnaturação Proteica/efeitos dos fármacos , Estrutura Terciária de Proteína , Espectrometria de Fluorescência/métodos , Ureia/farmacologiaRESUMO
The intracellular environment is overcrowded with a range of molecules (small and large), all of which influence protein conformation. As a result, understanding how proteins fold and stay functional in such crowded conditions is essential. Several in vitro experiments have looked into the effects of macromolecular crowding on different proteins. However, there are hardly any reports regarding small molecular crowders used alone and in mixtures to observe their effects on the structure and stability of the proteins, which mimics of the cellular conditions. Here we investigate the effect of different mixtures of crowders, ethylene glycol (EG) and its polymer polyethylene glycol (PEG 400 Da) on the structural and thermal stability of myoglobin (Mb). Our results show that monomer (EG) has no significant effect on the structure of Mb, while the polymer disrupts its structure and decreases its stability. Conversely, the additive effect of crowders showed structural refolding of the protein to some extent. Moreover, the calorimetric binding studies of the protein showed very weak interactions with the mixture of crowders. Usually, we can assume that soft interactions induce structural perturbations while exclusion volume effects stabilize the protein structure; therefore, we hypothesize that under in vivo crowded conditions, both phenomena occur and maintain the stability and function of proteins.
Assuntos
Substâncias Macromoleculares/química , Mioglobina/química , Redobramento de Proteína , Temperatura , Animais , Difusão Dinâmica da Luz , Etilenoglicol/química , Fluorescência , Guanidina/farmacologia , Cavalos , Hidrodinâmica , Simulação de Acoplamento Molecular , Polietilenoglicóis/química , Conformação Proteica , Desnaturação Proteica/efeitos dos fármacos , Redobramento de Proteína/efeitos dos fármacos , Estabilidade Proteica/efeitos dos fármacosRESUMO
Cyclin-Dependent Kinase 6 (CDK6) plays an important role in cancer progression, and thus, it is considered as an attractive drug target in anticancer therapeutics. This study presents an evaluation of dietary phytochemicals, capsaicin, tocopherol, rosmarinic acid, ursolic acid, ellagic acid (EA), limonene, caffeic acid, and ferulic acid for their potential to inhibit the activity of CDK6. Molecular docking and fluorescence binding studies revealed appreciable binding affinities of these compounds to the CDK6. Among them, EA shows the highest binding affinity for CDK6, and thus a molecular dynamics simulation study of 200 ns was performed to get deeper insights into the binding mechanism and stability of the CDK6-EA complex. Fluorescence binding studies revealed that EA binds to the CDK6 with a binding constant of K = 107 M-1 and subsequently inhibits its enzyme activity with an IC50 value of 3.053 µM. Analysis of thermodynamic parameters of CDK6-EA complex formation suggested a hydrophobic interaction driven process. The treatment of EA decreases the colonization of cancer cells and induces apoptosis. Moreover, the expression of CDK6 has been downregulated in EA-treated human breast cancer cell lines. In conclusion, this study establishes EA as a potent CDK6 inhibitor that can be further evaluated in CDK6 directed anticancer therapies.
Assuntos
Apoptose/efeitos dos fármacos , Neoplasias da Mama/enzimologia , Neoplasias da Mama/patologia , Quinase 6 Dependente de Ciclina/antagonistas & inibidores , Ácido Elágico/farmacologia , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Calorimetria , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Quinase 6 Dependente de Ciclina/química , Quinase 6 Dependente de Ciclina/metabolismo , Ácido Elágico/química , Feminino , Fluorescência , Humanos , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , TermodinâmicaRESUMO
Serum and glucocorticoid-regulated kinase 1 (SGK1) is a serine/threonine kinase that works under acute transcriptional control by several stimuli, including serum and glucocorticoids. It plays a significant role in the cancer progression and metastasis, as it regulates inflammation, apoptosis, hormone release, neuro-excitability, and cell proliferation. SGK1 has recently been considered as a potential drug target for cancer, diabetes, and neurodegenerative diseases. In the present study, we have performed structure-based virtual high-throughput screening of natural compounds from the ZINC database to find potential inhibitors of SGK1. Initially, hits were selected based on their physicochemical, absorption, distribution, metabolism, excretion, and toxicity (ADMET), and other drug-like properties. Afterwards, PAINS filter, binding affinities estimation, and interaction analysis were performed to find safe and effective hits. We found four compounds bearing appreciable binding affinity and specificity towards the binding pocket of SGK1. The docking results were complemented by all-atom molecular dynamics simulation for 100 ns, followed by MM/PBSA, and principal component analysis to investigate the conformational changes, stability, and interaction mechanism of SGK1 in-complex with the selected compound ZINC00319000. Molecular dynamics simulation results suggested that the binding of ZINC00319000 stabilizes the SGK1 structure, and it leads to fewer conformational changes. In conclusion, the identified compound ZINC00319000 might be further exploited as a scaffold to develop promising inhibitors of SGK1 for the therapeutic management of associated diseases, including cancer.