Effect of natural radionuclide's in the environment along the Jwalamukhi thrust of Himachal Pradesh, North West Himalayas, India.

This research paper is devoted to measure the activity contents of natural radionuclide, like, radium (226Ra), thorium (232Th) and potassium (40K) in the soil gathered along the Jwalamukhi thrust of Himachal Pradesh, North Western Himalayas, India. NaI(Tl) Scintillator detector was utilized for the estimation of activity content. The activity concentration of 226Ra, 232Th and 40K for some of the soil samples have been observed to be above the global normal mean values. The outcomes acquired for indoor and outdoor effective dosage are well below the normal international and national proposed results. The determined values of external hazard (Hex) for studied locations are less than unity, therefore; samples assembled from these regions are safe from a health hazard point of view and can be utilized as a construction purposes without producing any radio-logical hazard to human beings. The average estimations of radium equivalent activity were found to be within the limits suggested by Organization for Economic Cooperation and Development (OECD). Radon (222Rn) and thoron (220Rn) exhalation rates have also been calculated and discussed.

Uroflow nomogram for healthy, 15-40 year old Indian men.

INTRODUCTION: Uroflowmetry is the objective method of measuring rate of urine flow. Nomograms are required to observe the change in flow rates at different voided volumes (VVs) and the use of which overcomes the limitation of referencing flow rates to any single VV. The purpose of the present study was to construct the Indian uroflow nomogram for adult healthy males between 15-40 years of age. METHODS: A total of 1000 healthy males between 15 and 40 years of age were included in the study. Exclusion criteria were any urinary symptoms or urological intervention. Parameters analyzed statistically were age, peak flow rate (Qmax), average flow rate (Qavg), and VV. A nomogram was drawn for the fitted regression model. RESULTS: The mean age was 27.26 ± 6.71 years. The mean Qmax, Qavg, and VV were 24.32 ± 3.50 ml/s, 9.45 ± 2.55 ml/s, and 420.93 ± 97.89 ml, respectively. The correlation between flow rates and VV was statistically significant, indicating that the higher the VV, the higher the flow rates. A negative significant correlation of Qmax with age was seen in our study. We observed a decline of Qmax by 1 ml/s/decade. The relationship of Qmax with VV is in linear progression up to 600 ml, and then it becomes a plateau and with higher VV it declined. CONCLUSION: Qmax exhibits significant correlation with VV and age. A nomogram was constructed to attain normal reference values of flow rate over different VVs.

Mechanistic insight into the enzymatic reduction of truncated hemoglobin N of Mycobacterium tuberculosis: role of the CD loop and pre-A motif in electron cycling.

Many pathogenic microorganisms have evolved hemoglobin-mediated nitric oxide (NO) detoxification mechanisms, where a globin domain in conjunction with a partner reductase catalyzes the conversion of toxic NO to innocuous nitrate. The truncated hemoglobin HbN of Mycobacterium tuberculosis displays a potent NO dioxygenase activity despite lacking a reductase domain. The mechanism by which HbN recycles itself during NO dioxygenation and the reductase that participates in this process are currently unknown. This study demonstrates that the NADH-ferredoxin/flavodoxin system is a fairly efficient partner for electron transfer to HbN with an observed reduction rate of 6.2 µM/min(-1), which is nearly 3- and 5-fold faster than reported for Vitreoscilla hemoglobin and myoglobin, respectively. Structural docking of the HbN with Escherichia coli NADH-flavodoxin reductase (FdR) together with site-directed mutagenesis revealed that the CD loop of the HbN forms contacts with the reductase, and that Gly(48) may have a vital role. The donor to acceptor electron coupling parameters calculated using the semiempirical pathway method amounts to an average of about 6.4 10(-5) eV, which is lower than the value obtained for E. coli flavoHb (8.0 10(-4) eV), but still supports the feasibility of an efficient electron transfer. The deletion of Pre-A abrogated the heme iron reduction by FdR in the HbN, thus signifying its involvement during intermolecular interactions of the HbN and FdR. The present study, thus, unravels a novel role of the CD loop and Pre-A motif in assisting the interactions of the HbN with the reductase and the electron cycling, which may be vital for its NO-scavenging function.

Type I flavohemoglobin of mycobacterium smegmatis is a functional nitric oxide dioxygenase.

Two flavohemoglobins, type I and type II, displaying distinct structural features and cofactor binding sites coexist in Mycobacterium smegmatis; however, none of these flavohemeproteins are characterized so far. We have cloned and expressed type I flavohemoglobin (FHb1) of Mycobacterium smegmatis, encoded by MSMEG_1336, and characterized its spectral and functional properties. FHb1 exists as a monomer and displays spectral and functional characteristics similar to HMP of E. coli. Specific NO dioxygenase (NOD) activity of FHb1 was estimated to be 63.5 nmol heme(-1) sec(-1) , which was nearly eightfold higher than the HbN of M. tuberculosis and matched closely to the HMP of E. coli on the basis of cellular heme content. FHb1 preferred NADH for the NO dioxygenation and exhibited rapid reduction of flavin adenine dinucleotide and heme iron using NADH as electron donor. Level of FHb1 transcript increased significantly in M. smegmatis in the presence of acidified nitrite, and a nitric oxide-responsive transcriptional regulator of Rrf2 family exists together with the FHb1 under the same operon. These results suggested that FHb1 of M. smegmatis is a functional NOD and may be involved in the stress management of its host toward nitric oxide and nitrosative stress.

Investigation of the efficacy of Zn/Ce-CuO nanoparticles for enhanced photocatalytic, antibacterial, and antioxidant activities.

The world is dealing with unprecedented environmental challenges, leading to a growing urgency to limit environmental damage. So, this study focuses on the synthesis of pure CuO, Zn, Ce, and Zn/Ce dual-doped CuO nanoparticles (NPs) using extract of Citrus limon leaves as reductant via simple co-precipitation method. The X-ray diffraction (XRD) characterization was employed to analyze structural characteristics of synthesized samples which confirm influence of Zn or Ce doping on crystallite size, dislocation density, and strain. The role of functional groups, changes in force constant, and bond length on addition of dopants was indicated by FTIR results. The SEM and TEM results showed variation in morphology from irregular to spherical. The zeta-potential and BET analysis confirmed surface potential as well as surface area characteristics. The change in energy gap values from 1.81 to 1.45 eV of Zn/Ce-doped CuO NPs computed from UV-vis analysis elevated its photocatalytic performance and reduced the chances of recombination of electron-hole pair due to presence of trapping levels between valence and conduction bands. The enhanced photo-degradation of Congo red (CR) and rhodamine B (RhB) with 91 and 94%, respectively, for Zn/Ce-doped CuO NPs was observed. The so-obtained samples have also exhibited good antibacterial and antioxidant activities.

Green synthesis and multifunctional properties of Cu/NiO nanocomposites using Commelina benghalensis leaf extract.

This study presents the green synthesis and multifunctional properties of Cu/NiO nanocomposites (NCs) fabricated with varying ratios (90:10, 80:20, and 70:30) using Commelina benghalensis leaf extract. X-ray diffraction (XRD) analysis confirmed the polycrystalline nature of the NCs, revealing crystallite sizes of 13.62, 13.22, and 7.14 nm. Scanning electron microscopy (SEM) showed rod-shaped and agglomerated particles with sizes ranging from 17.64 to 22.97 nm. Energy-dispersive X-ray spectroscopy (EDX) verified the elemental composition of copper, nickel, oxygen, and carbon. UV-visible spectroscopy determined the energy band gaps to be in the range of 1.24-1.56 eV. Fourier-transform infrared spectroscopy (FT-IR) indicated the presence of bioactive compounds responsible for the reduction of precursor metal salts. The Cu/NiO NCs exhibited remarkable antimicrobial activity, with the 90:10 ratio showing the highest zones of inhibition at 32.76 ± 0.23 mm, 18.66 ± 0.33 mm, and 14.36 ± 0.32 mm against Bacillus subtilis, Staphylococcus aureus, and Escherichia coli, respectively. Additionally, the 70:30 Cu/NiO NCs demonstrated superior antioxidant activity, with a radical scavenging efficiency of 83.22%, closely approaching that of ascorbic acid (96.98%). Photocatalytic evaluations revealed that the NCs were highly effective in degrading environmental pollutants, achieving 97.69% degradation of malachite green and 96.52% of congo red under UV light irradiation. The novelty of this work lies in the use of Commelina benghalensis leaf extract as a sustainable and eco-friendly reducing and stabilizing agent for synthesizing Cu/NiO NCs, offering a green alternative to conventional methods. The synergistic effects between Cu and NiO in the different compositions (90:10, 80:20, and 70:30) enhanced the overall antimicrobial and photocatalytic activities, highlighting their potential for environmental remediation applications.

A critical review on the recent trends of photocatalytic, antibacterial, antioxidant and nanohybrid applications of anatase and rutile TiO2 nanoparticles.

Titanium dioxide nanoparticles (TiO2 NPs) have become a focal point of research due to their widespread daily use and diverse synthesis methods, including physical, chemical, and environmentally sustainable approaches. These nanoparticles possess unique attributes such as size, shape, and surface functionality, making them particularly intriguing for applications in the biomedical field. The continuous exploration of TiO2 NPs is driven by the quest to enhance their multifunctionality, aiming to create next-generation products with superior performance. Recent research efforts have specifically focused on understanding the anatase and rutile phases of TiO2 NPs and evaluating their potential in various domains, including photocatalytic processes, antibacterial properties, antioxidant effects, and nanohybrid applications. The hypothesis guiding this research is that by exploring different synthesis methods, particularly chemical and environmentally friendly approaches, and incorporating doping and co-doping techniques, the properties of TiO2 NPs can be significantly improved for diverse applications. The study employs a comprehensive approach, investigating the effects of nanoparticle size, shape, dose, and exposure time on performance. The synthesis methods considered encompass both conventional chemical processes and environmentally friendly alternatives, with a focus on how doping and co-doping can enhance the properties of TiO2 NPs. The research unveils valuable insights into the distinct phases of TiO2 NPs and their potential across various applications. It sheds light on the improved properties achieved through doping and co-doping, showcasing advancements in photocatalytic processes, antibacterial efficacy, antioxidant capabilities, and nanohybrid applications. The study concludes by emphasizing regulatory aspects and offering suggestions for product enhancement. It provides recommendations for the reliable application of TiO2 NPs, addressing a comprehensive spectrum of critical aspects in TiO2 NP research and application. Overall, this research contributes to the evolving landscape of TiO2 NP utilization, offering valuable insights for the development of innovative and high-performance products.

A protein-proximity screen reveals Ebola virus co-opts the mRNA decapping complex through the scaffold protein EDC4.

The interaction of host and Ebola virus (EBOV) proteins is required for establishing infection of the cell. To identify protein binding partners, a proximity-dependent protein interaction screen was performed for six EBOV proteins. Hits were computationally mapped onto a human protein-protein interactome and then annotated with viral proteins to reveal known and previously undescribed EBOV-host protein interactions and processes. Importantly, this approach efficiently arranged proteins into functional complexes associated with single viral proteins. Focused characterization of interactions between EBOV VP35 and the mRNA decapping complex demonstrated that VP35 binds the scaffold protein EDC4 through the C-terminal subdomain, with each protein found associated in EBOV-infected cells. Mechanistically, depletion of three components of the complex each similarly inhibited viral replication by reducing early viral RNA synthesis. Overall, we demonstrate successful identification of EBOV protein interaction with entire cellular machines, providing a deeper understanding of replication mechanism for therapeutic intervention.

Membrane mimetic-dependence of GPCR energy landscapes.

We leveraged variable-temperature 19F-NMR spectroscopy to compare the conformational equilibria of the human A2A adenosine receptor (A2AAR), a class A G protein-coupled receptor (GPCR), across a range of temperatures ranging from lower temperatures typically employed in 19F-NMR experiments to physiological temperature. A2AAR complexes with partial agonists and full agonists showed large increases in the population of a fully active conformation with increasing temperature. NMR data measured at physiological temperature were more in line with functional data. This was pronounced for complexes with partial agonists, where the population of active A2AAR was nearly undetectable at lower temperature but became evident at physiological temperature. Temperature-dependent behavior of complexes with either full or partial agonists exhibited a pronounced sensitivity to the specific membrane mimetic employed. Cellular signaling experiments correlated with the temperature-dependent conformational equilibria of A2AAR in lipid nanodiscs but not in some detergents, underscoring the importance of the membrane environment in studies of GPCR function.

Single-cell image-based genetic screens systematically identify regulators of Ebola virus subcellular infection dynamics.

Ebola virus (EBOV) is a high-consequence filovirus that gives rise to frequent epidemics with high case fatality rates and few therapeutic options. Here, we applied image-based screening of a genome-wide CRISPR library to systematically identify host cell regulators of Ebola virus infection in 39,085,093 million single cells. Measuring viral RNA and protein levels together with their localization in cells identified over 998 related host factors and provided detailed information about the role of each gene across the virus replication cycle. We trained a deep learning model on single-cell images to associate each host factor with predicted replication steps, and confirmed the predicted relationship for select host factors. Among the findings, we showed that the mitochondrial complex III subunit UQCRB is a post-entry regulator of Ebola virus RNA replication, and demonstrated that UQCRB inhibition with a small molecule reduced overall Ebola virus infection with an IC50 of 5 µM. Using a random forest model, we also identified perturbations that reduced infection by disrupting the equilibrium between viral RNA and protein. One such protein, STRAP, is a spliceosome-associated factor that was found to be closely associated with VP35, a viral protein required for RNA processing. Loss of STRAP expression resulted in a reduction in full-length viral genome production and subsequent production of non-infectious virus particles. Overall, the data produced in this genome-wide high-content single-cell screen and secondary screens in additional cell lines and related filoviruses (MARV and SUDV) revealed new insights about the role of host factors in virus replication and potential new targets for therapeutic intervention.

Removal of organic dyes and free radical assay by encapsulating polyvinylpyrrolidone and Tinospora Cordifolia in dual (Co-Cu) doped TiO2 nanoparticles.

Aquatic pollution refers to any water that has been used and discarded in different water bodies by industrial and commercial activities which contains a wide range of toxic substances and required treatment so that water can be safely reused for various purposes. In present paper, polymer polyvinylpyrrolidone (PVP) and plant Tinospora Cordifolia (T. Cordifolia) encapsulated dual doped cobalt-copper titanium dioxide nanoparticles (Co-Cu TNPs) has been synthesized via microwave-assisted method for the degradation aquatic pollutant dyes: Methyl Orange (MO) & Methylene Blue (MB). Using the encapsulated dual doped Co-Cu TNPs, free radical assays (2,2-diphenyl-1-picrylhydrazyl: DPPH; Hydrogen peroxide: HP & Nitric oxide: NO) were also performed. Several physicochemical properties of encapsulated TNPs were examined using a variety of characterization techniques that helps in photocatalytic and antioxidant activity. The encapsulated TNPs exhibit tetragonal crystal lattice having average particles size between 25 and 38 nm with spherical shape morphology. The bandgap of encapsulated dual doped Co-Cu TNPs was found in the range of 3.25-3.29 eV. The binding of encapsulated dual doped Co-Cu TNPs were also calculated by using XPS which confirms the presence of dopants. The photocatalytic activity was performed with using control experiment and using encapsulated dual doped Co-Cu TNPs against MO and MB dyes. The results revealed that the degradation was observed up to 100% for the both MO and MB dyes. Also, antioxidant activity of encapsulated dual doped Co-Cu TNPs was observed against the DPPH, HO and NO assays.

Dual mechanisms of cholesterol-GPCR interactions that depend on membrane phospholipid composition.

Cholesterol is a critical component of mammalian cell membranes and an allosteric modulator of G protein-coupled receptors (GPCRs), but divergent views exist on the mechanisms by which cholesterol influences receptor functions. Leveraging the benefits of lipid nanodiscs, i.e., quantitative control of lipid composition, we observe distinct impacts of cholesterol in the presence and absence of anionic phospholipids on the function-related conformational dynamics of the human A2A adenosine receptor (A2AAR). Direct receptor-cholesterol interactions drive activation of agonist-bound A2AAR in membranes containing zwitterionic phospholipids. Intriguingly, the presence of anionic lipids attenuates cholesterol's impact through direct interactions with the receptor, highlighting a more complex role for cholesterol that depends on membrane phospholipid composition. Targeted amino acid replacements at two frequently predicted cholesterol interaction sites showed distinct impacts of cholesterol at different receptor locations, demonstrating the ability to delineate different roles of cholesterol in modulating receptor signaling and maintaining receptor structural integrity.

Illuminating GPCR signaling mechanisms by NMR spectroscopy with stable-isotope labeled receptors.

G protein-coupled receptors (GPCRs) exhibit remarkable structural plasticity, which underlies their capacity to recognize a wide range of extracellular molecules and interact with intracellular partner proteins. Nuclear magnetic resonance (NMR) spectroscopy is uniquely well-suited to investigate GPCR structural plasticity, enabled by stable-isotope "probes" incorporated into receptors that inform on structure and dynamics. Progress with stable-isotope labeling methods in Eukaryotic expression systems has enabled production of native or nearly-native human receptors with varied and complementary distributions of NMR probes. These advances have opened up new avenues for investigating the roles of conformational dynamics in signaling processes, including by mapping allosteric communication networks, understanding the specificity of GPCR interactions with partner proteins and exploring the impact of membrane environments on GPCR function.

Membrane Mimetic-Dependence of GPCR Energy Landscapes.

Protein function strongly depends on temperature, which is related to temperature-dependent changes in the equilibria of protein conformational states. We leveraged variable-temperature 19F-NMR spectroscopy to interrogate the temperature dependence of the conformational landscape of the human A2A adenosine receptor (A2AAR), a class A GPCR. Temperature-induced changes in the conformational equilibria of A2AAR in lipid nanodiscs were markedly dependent on the efficacy of bound drugs. While antagonist complexes displayed only modest changes as the temperature rose, both full and partial agonist complexes exhibited substantial increases in the active state population. Importantly, the temperature-dependent response of complexes with both full and partial agonists exhibited a pronounced sensitivity to the specific membrane mimetic employed. In striking contrast to observations within lipid nanodiscs, in detergent micelles the active state population exhibited different behavior for A2AAR complexes with both full and partial agonists. This underscores the importance of the protein environment in understanding the thermodynamics of GPCR activation.

Biomass waste-derived carbon materials for sustainable remediation of polluted environment: A comprehensive review.

In response to the growing global concern over environmental pollution, the exploration of sustainable and eco-friendly materials derived from biomass waste has gained significant traction. This comprehensive review seeks to provide a holistic perspective on the utilization of biomass waste as a renewable carbon source, offering insights into the production of environmentally benign and cost-effective carbon-based materials. These materials, including biochar, carbon nanotubes, and graphene, have shown immense promise in the remediation of polluted soils, industrial wastewater, and contaminated groundwater. The review commences by elucidating the intricate processes involved in the synthesis and functionalization of biomass-derived carbon materials, emphasizing their scalability and economic viability. With their distinctive structural attributes, such as high surface areas, porous architectures, and tunable surface functionalities, these materials emerge as versatile tools in addressing environmental challenges. One of the central themes explored in this review is the pivotal role that carbon materials play in adsorption processes, which represent a green and sustainable technology for the removal of a diverse array of pollutants. These encompass noxious organic compounds, heavy metals, and organic matter, encompassing pollutants found in soils, groundwater, and industrial wastewater. The discussion extends to the underlying mechanisms governing adsorption, shedding light on the efficacy and selectivity of carbon-based materials in different environmental contexts. Furthermore, this review delves into multifaceted considerations, spanning the spectrum from biomass and biowaste resources to the properties and applications of carbon materials. This holistic approach aims to equip researchers and practitioners with a comprehensive understanding of the synergistic utilization of these materials, ultimately facilitating effective and affordable strategies for combatting industrial wastewater pollution, soil contamination, and groundwater impurities.

Single-molecule visualization of human A2A adenosine receptor activation by a G protein and constitutively activating mutations.

Mutations that constitutively activate G protein-coupled receptors (GPCRs), known as constitutively activating mutations (CAMs), modify cell signaling and interfere with drugs, resulting in diseases with limited treatment options. We utilize fluorescence imaging at the single-molecule level to visualize the dynamic process of CAM-mediated activation of the human A2A adenosine receptor (A2AAR) in real time. We observe an active-state population for all CAMs without agonist stimulation. Importantly, activating mutations significantly increase the population of an intermediate state crucial for receptor activation, notably distinct from the addition of a partner G protein. Activation kinetics show that while CAMs increase the frequency of transitions to the intermediate state, mutations altering sodium sensitivity increase transitions away from it. These findings indicate changes in GPCR function caused by mutations may be predicted based on whether they favor or disfavor formation of an intermediate state, providing a framework for designing receptors with altered functions or therapies that target intermediate states.

Anionic Phospholipids Control Mechanisms of GPCR-G Protein Recognition.

G protein-coupled receptors (GPCRs) are embedded in phospholipids that strongly influence drug-stimulated signaling. Anionic lipids are particularly important for GPCR signaling complex formation, but a mechanism for this role is not understood. Using NMR spectroscopy, we visualized the impact of anionic lipids on the function-related conformational equilibria of the human A 2A adenosine receptor (A 2A AR) in bilayers containing defined mixtures of zwitterionic and anionic phospholipids. Anionic lipids primed the receptor to form complexes with G proteins through a conformational selection process. Without anionic lipids, signaling complex formation proceeded through a less favorable induced fit mechanism. In computational models, anionic lipids mimicked interactions between a G protein and positively charged residues in A 2A AR at the receptor intracellular surface, stabilizing a pre-activated receptor conformation. Replacing these residues strikingly altered the receptor response to anionic lipids in experiments. High sequence conservation of the same residues among all GPCRs supports a general role for lipid-receptor charge complementarity in signaling.

Anionic phospholipids control mechanisms of GPCR-G protein recognition.

G protein-coupled receptors (GPCRs) are embedded in phospholipids that strongly influence drug-stimulated signaling. Anionic lipids are particularly important for GPCR signaling complex formation, but a mechanism for this role is not understood. Using NMR spectroscopy, we explore the impact of anionic lipids on the function-related conformational equilibria of the human A2A adenosine receptor (A2AAR) in bilayers containing defined mixtures of zwitterionic and anionic phospholipids. Anionic lipids prime the receptor to form complexes with G proteins through a conformational selection process. Without anionic lipids, signaling complex formation proceeds through a less favorable induced fit mechanism. In computational models, anionic lipids mimic interactions between a G protein and positively charged residues in A2AAR at the receptor intracellular surface, stabilizing a pre-activated receptor conformation. Replacing these residues strikingly alters the receptor response to anionic lipids in experiments. High sequence conservation of the same residues among all GPCRs supports a general role for lipid-receptor charge complementarity in signaling.

Ebolavirus Species-Specific Interferon Antagonism Mediated by VP24.

Members of the Ebolavirus genus demonstrate a marked differences in pathogenicity in humans with Ebola (EBOV) being the most pathogenic, Bundibugyo (BDBV) less pathogenic, and Reston (RESTV) is not known to cause a disease in humans. The VP24 protein encoded by members of the Ebolavirus genus blocks type I interferon (IFN-I) signaling through interaction with host karyopherin alpha nuclear transporters, potentially contributing to virulence. Previously, we demonstrated that BDBV VP24 (bVP24) binds with lower affinities to karyopherin alpha proteins relative to EBOV VP24 (eVP24), and this correlated with a reduced inhibition in IFN-I signaling. We hypothesized that modification of eVP24-karyopherin alpha interface to make it similar to bVP24 would attenuate the ability to antagonize IFN-I response. We generated a panel of recombinant EBOVs containing single or combinations of point mutations in the eVP24-karyopherin alpha interface. Most of the viruses appeared to be attenuated in both IFN-I-competent 769-P and IFN-I-deficient Vero-E6 cells in the presence of IFNs. However, the R140A mutant grew at reduced levels even in the absence of IFNs in both cell lines, as well as in U3A STAT1 knockout cells. Both the R140A mutation and its combination with the N135A mutation greatly reduced the amounts of viral genomic RNA and mRNA suggesting that these mutations attenuate the virus in an IFN-I-independent attenuation. Additionally, we found that unlike eVP24, bVP24 does not inhibit interferon lambda 1 (IFN-λ1), interferon beta (IFN-ß), and ISG15, which potentially explains the lower pathogenicity of BDBV relative to EBOV. Thus, the VP24 residues binding karyopherin alpha attenuates the virus by IFN-I-dependent and independent mechanisms.

Global insights into the fine tuning of human A2AAR conformational dynamics in a ternary complex with an engineered G protein viewed by NMR.

G protein-coupled receptor (GPCR) conformational plasticity enables formation of ternary signaling complexes with intracellular proteins in response to binding extracellular ligands. We investigate the dynamic process of GPCR complex formation in solution with the human A2A adenosine receptor (A2AAR) and an engineered Gs protein, mini-Gs. 2D nuclear magnetic resonance (NMR) data with uniform stable isotope-labeled A2AAR enabled a global comparison of A2AAR conformations between complexes with an agonist and mini-Gs and with an agonist alone. The two conformations are similar and show subtle differences at the receptor intracellular surface, supporting a model whereby agonist binding alone is sufficient to populate a conformation resembling the active state. However, an A2AAR "hot spot" connecting the extracellular ligand-binding pocket to the intracellular surface is observed to be highly dynamic in the ternary complex, suggesting a mechanism for allosteric connection between the bound G protein and the drug-binding pocket involving structural plasticity of the "toggle switch" tryptophan.