ABSTRACT
In the current study, the compound 4,4-dimethoxychalcone (DMC) was structurally studied and analyzed by in silico approach against Mpro to investigate its inhibitory potential. The molecular structure of the compound was confirmed by the single crystal X-ray diffraction studies. The crystal structure packing is characterized by various hydrogen bonds, C-H…π and π…π stacking. Intermolecular interactions are quantified by Hirshfeld surface analysis and the electronic structure was optimized by DFT calculations;results are in agreement with the experimental studies. Further, DMC was virtually screened against SARS-CoV-2 main protease (PDB-ID: 6LU7) using molecular docking, and molecular dynamics (MD) simulations to identify its inhibitory potential. A significant binding affinity exists between DMC and Mpro with a-6.00 kcal/mol binding energy. A MD simulation of 30ns was carried out;the results predict DMC possessing strong binding affinity and hydrogen-bonding interactions within the active site during the simulation period. Therefore, based on the results of the current investigation, it can be inferred that a DMC molecule may be able to inhibit Mpro of COVID-19. © 2023 by the authors;licensee Growing Science, Canada.
ABSTRACT
A novel phenoxy-bridged trinuclear nickel(ii) complex [Ni3(mu-L)2(bipy)3](1) (where H3L= (E)-2-hydroxy-N-(2-hydroxy-3,5-diiodophenyl)-3,5-diiodobenzohydrazonic acid, bipy = 2,2'-bipyridyl) has been designed and synthesized as a potential antivirus drug candidate. The trinuclear Ni(ii) complex [Ni3(mu-L)2(bipy)3](1) was fully characterized via single crystal X-ray crystallography. The unique structure of the trinuclear nickel(ii) complex crystallized in a trigonal crystal system with P3221 space group and revealed distorted octahedral coordination geometry around each Ni(ii) ion. The X-ray diffraction analysis established the existence of a new kind of trinuclear metal system containing nickel(ii)-nickel(ii) interactions with an overall octahedral-like geometry about the nickel(ii) atoms. The non-bonded Ni-Ni distance seems to be 3.067 and 4.455 A from the nearest nickel atoms. The detailed structural analysis and non-covalent supramolecular interactions are also investigated by single crystal structure analysis and computational approaches. Hirshfeld surfaces (HSs) and 2D fingerprint plots (FPs) have been explored in the crystal structure to investigate the intermolecular interactions. The preliminary analysis of redox and magnetic characterization was conducted using cyclic voltammetry measurements and a vibrating sample magnetometer (VSM), respectively. This unique structure shows good inhibition performance for SARS-CoV-2, Omicron and HIV viruses. For insight into the potential application of the Ni(ii) coordination complex as an effective antivirus drug, we have examined the molecular docking of the trinuclear Ni(ii) complex [Ni3(mu-L)2(bipy)3](1) with the receptor binding domain (RBD) from SARS-CoV-2 (PDB ID: 7MZF), Omicron BA.3 variant spike (PDB ID: 7XIZ), and HIV protease (PDB ID: 7WCQ) viruses. This structure shows good inhibition performance for SARS-CoV-2, Omicron S protein and HIV protease viruses;the binding energies (DELTAG) and the respective Ki/Kd (inhibition/dissociation constants) correlation values are -8.9 (2.373 muM or 2373 nM), -8.1 (1.218 muM or 1218 nM) and -7.9 (0.874 muM or 874 nM), respectively. The results could be used for rational drug design against SARS-CoV-2 Omicron variant and HIV protease viruses.Copyright © 2023 The Royal Society of Chemistry.
ABSTRACT
In this investigation a single crystal of (4-oxo-piperidinium ethylene acetal) trioxonitrate (4-OPEAN) was synthesized by modifying the mechanism of gradual evaporation at ambient temperature. The operational groupings are found in the complex material in the elaborate substance, according to the infrared spectrum. Single crystal X-ray diffraction suggests, (4-OPEAN) with the chemical formula (C7H12NO2)NO3 belongs to the orthorhombic space group Pnma and is centrosymmetric in three dimensions with the aforementioned network configurations, a = 11.7185(8) Å, b = 7.2729(6) Å, c = 11.0163(8) Å, Z = 4, V = 938.89(12) Å3, R = 0.0725 and wR = 0.1762. Many N-H O and C-H O hydrogen bridges, both bifurcated and non-bifurcated, link the 4-oxo-piperidinium ethylene acetal cations to the trigonal (NO3-) anions. Molecular geometry and optimal parameters of (4-OPEAN) have been determined via DFT computations at the theory-level B3LYP/6-311 ++ G(d, p), these have been contrasted with the X-ray data already available. Hirshfeld surface analysis has made it possible for the visualization and quantification of relationships between molecules in the crystal composition. Quantum theory atoms in molecules, electron location function, decreased density gradient, and localized orbital locator research have all been used to explore non-covalent interactions in crystal structure. In order to pinpoint both the nucleophilic and electrophilic locations that support hydrogen bond formation, the molecule electrostatic potential was determined. The greatest and lowest energies of occupied and unfilled molecular orbitals, together with additional derived atomic characteristics, show the material to be extremely stable and hard. According to a molecular docking study, 4-OPEAN may exhibit inhibiting effects on the 6Y84 and 7EJY virus proteins from corona (COVID-19).
ABSTRACT
The recent studies have indicated the requisite of computed tomography scan analysis by radiologists extensively to find out the suspected patients of SARS-CoV-2 (COVID-19). The existing deep learning methods distribute one or more of the subsequent bottlenecks. Therefore, a straight forward method for detecting COVID-19 infection using real-world computed tomography scans is presented. The detection process consists of image processing techniques such as segmentation of lung parenchyma and extraction of effective texture features. The kernel-based support vector machine is employed over feature vectors for classification. The performance parameters of the proposed method are calculated and compared with the existing methodology on the same dataset. The classification results are found outperforming and the method is less probabilistic which can be further exploited for developing more realistic detection system.Copyright © 2023 Inderscience Enterprises Ltd.
ABSTRACT
The study of tautomerism in biologically relevant heterocycles is essential, as it directly affects their chemical properties and biological function. Lactam-lactim tautomerization in pyridine/pyrazine derivatives is such a phenomenon. Favipiravir, a pyrazine derivative, is an essential antiviral drug molecule having notable performance against SARS-CoV-2. Along with a better yielding synthetic method for favipiravir, we have also investigated the lactam-lactim tautomerization of favipiravir and its analogous molecules. Most of these molecules were crystalized and studied for various interactions in their lattice. Many interesting supramolecular interactions such as hydrogen bonding, pi-pi stacking and halogen bonding were revealed during the analysis. Some of these structures show interesting F-F halogen bonding and water channels in their solid state.Copyright © 2022 The Royal Society of Chemistry.
ABSTRACT
Two inexpensive and simple methods for synthesis of carbon nanodots were applied and compared to each other, namely a hydrothermal and microwave-assisted method. The synthesized carbon nanodots were characterized using transmission electron microscopy (TEM), ultraviolet-visible (UV-Vis), photoluminescence (PL), Fourier transform-infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The synthesized microwave carbon nanodots had smaller particle size and were thus chosen for better electrochemical performance. Therefore, they were used for our modification process. The proposed electrodes performance characteristics were evaluated according to the IUPAC guidelines, showing linear response in the concentration range 10−6–10−2, 10−7–10−2, and 10−8–10−2 M of tobramycin with a Nernstian slope of 52.60, 58.34, and 57.32 mV/decade for the bare, silver nanoparticle and carbon nanodots modified carbon paste electrodes, respectively. This developed potentiometric method was used for quantification of tobramycin in its co-formulated dosage form and spiked human plasma with good recovery percentages and without interference of the co-formulated drug loteprednol etabonate and excipients.
ABSTRACT
Abstract: PhOMe-salophen (1b) (salophen is N,N-bis(salycilidene)-1,2-phenylenediamine with two tert-butyl on each ring) and Cu(II) complex with PhOMe-salophen (1c) have been synthesized and characterized using various tools, including X-ray diffraction for the Cu(II)-complex (1c, C43H52CuN2O3)). The copper complex has been obtained by Cu2+ templated approach using 1b. PhOMe-salophen (1b) has been obtained in reasonably high yield using a mixture of the Schiff-base, 1a, Pd(OAc)2, PPh3, Na2CO3, 4-methoxyphenylboronic acid in benzene. We focus in this research work on the electronic and structural properties of the Cu–Schiff base complex. The tetra-coordinate τ4 index was calculated, indicating almost a perfect square planner in agreement with X-ray diffraction results. MEP reveals the maximum positive regions in 1/-associated with the azomethine and methoxyphenyl C–H bonds with an average value of 0.03 a.u. Hirshfeld surface analysis (HSA) was also studied to highlight the significant inter-atomic contacts and their percentage contribution through 2D Fingerprint plot. In a fair comparative molecular docking study, 1b and 1c were docked together with N-[{(5-methylisoxazol-3-yl)-carbonyl}alanyl}-l-valyl]-N1-((1R,2Z)-4-(benzyloxy)-4-oxo-1-[{(3R)-2-oxopyrrolidin-3-yl}methyl]but-2-enyl)-l-leucinamide, N3 against main protease Mpro, (PDB code 7BQY) using the same parameters and conditions. Interesting here to use the free energy, in silico, molecular docking approach, which aims to rank our molecules with respect to the well-known inhibitor, N3. The binding scores of 1b, 1c, N3 are –7.8, –9.0, and –8.4 kcal/mol, respectively. These preliminary results propose that ligands deserve additional study in the context of possible remedial agents for COVID-19. © 2022, Pleiades Publishing, Ltd.
ABSTRACT
The mass casualties caused by the delta variant and the wave of the newer "Omicron" variant of SARS-COV-2 in India have brought about great concern among healthcare officials. The government and healthcare agencies are seeking effective strategies to counter the pandemic. The application of nanotechnology and repurposing of drugs are reported as promising approaches in the management of COVID-19 disease. It has also immensely boomed the search for productive, re-liable, cost-effective, and bio-assimilable alternative solutions. Since ancient times, the traditional-ly employed Ayurvedic bhasmas have been used for diverse infectious diseases, which are now employed as nanomedicine that could be applied for managing COVID-19-related health anomalies. Like currently engineered metal nanoparticles (NPs), the bhasma nanoparticles (BNPs) are also packed with unique physicochemical properties, including multi-elemental nanocrystalline compo-sition, size, shape, dissolution, surface charge, hydrophobicity, and multi-pathway regulatory as well as modulatory effects. Because of these conformational and configurational-based physico-chemical advantages, Bhasma NPs may have promising potential to manage the COVID-19 pandemic and reduce the incidence of pneumonia-like common lung infections in children as well as age-related inflammatory diseases via immunomodulatory, anti-inflammatory, antiviral, and adju-vant-related properties.Copyright © 2023 Bentham Science Publishers.
ABSTRACT
Tiny air sacs in one or both lungs become inflamed as a result of the lung infection known as pneumonia. In order to provide the best possible treatment plan, pneumonia must be accurately and quickly diagnosed at initial stages. Nowadays, a chest X-ray is regarded as the most effective imaging technique for detecting pneumonia. However, performing chest X-ray analysis may be quite difficult and laborious. For this purpose, in this study we propose deep convolutional neural network (CNN) with 24 hidden layers to identify pneumonia using chest X-ray images. In order to get high accuracy of the proposed deep CNN we applied an image processing method as well as rescaling and data augmentation methods as shear_range, rotation, zooming, CLAHE, and vertical_flip. The proposed approach has been evaluated using different evaluation criteria and has demonstrat-ed 97.2%, 97.1%, 97.43%, 96%, 98.8% performance in terms of accuracy, precision, recall, F-score, and AUC-ROC curve. Thus, the applied deep CNN obtain a high level of performance in pneumonia detection. In general, the provided approach is intended to aid radiologists in making an accurate pneumonia diagnosis. Additionally, our suggested models could be helpful in the early detection of other chest-related illnesses such as COVID-19 © 2023, International Journal of Advanced Computer Science and Applications.All Rights Reserved.
ABSTRACT
The Covid-19 crisis has led to a massive surge in the use of surgical masks worldwide, causing risks of shortages and high pollution. Various decontamination techniques are currently being studied to reduce these risks by allowing the reuse of masks. In this study, surgical masks were washed up to 10 times, each cycle under the same conditions. The consequences of the washing cycles on the structure, fiber morphology, and surface chemistry have been studied through several characterization techniques: scanning electron microscopy, wetting angle measurements, infrared spectroscopy, X-ray diffraction, and X-ray photoelectrons spectroscopy. The washing process did not induce large changes in the hydrophobicity of the surface, the contact angle remaining constant throughout the cycles. The composition observed in the IR spectrum also remained unchanged for washed masks up to 10 cycles. Some slight variations were observed during X-ray analysis: the crystallinity of the fibers as well as the size of the crystals increases with the number of wash cycles. The XPS analysis shows that after 10 cycles, the surface of the masks underwent a slight oxidation. In the SEM images, changes were observed in the arrangement of the fibers, which are more visible the more times the mask has been washed: they align themselves in bundles, form areas with holes in the mask layer, and are crushed in some areas. © 2023 American Chemical Society
ABSTRACT
Herein, we report two novel multidentate luminogen proligands bis(3,5-diiodosalicylidene) carbohydrazone (H4L1) and bis(3,5-diiodosalicylidene) thiocarbohydrazone (H4L2), which are suitable candidates for biomedical applications. Though the thiocarbohydrazone H4L2 shows aggregation caused quenching (ACQ), the carbohydrazone H4L1 exhibits stronger fluorescence due to aggregation induced emission enhancement (AIEE). Molecular docking studies of H4L1 and H4L2 along with four similar (thio)carbohydrazones with the active sites of SARS-CoV-2 main protease 3CLpro reveals that the thiocarbohydrazones, in general, are showing better propensity compared to their oxygen analogues. Both the thiocarbohydrazones and the carbohydrazones, however, exhibit better binding potential at the active sites than that of some of the repurposed drugs such as chloroquine, hydroxychloroquine, lopinavir, ritonavir, darunavir and remdesivir. Also, the carbohydrazone H4L1 can be a better bioprobe compared to H4L2 as the former is found to have better binding potential with SARS-CoV-2 spike glycoprotein along with AIEE feature.
ABSTRACT
Biomimetic strategies can be adopted to improve biopharmaceutical aspects. Subsequently, Biomimetic reconstitutable pegylated amphiphilic lipid nanocarriers have high translational potential for systemic controlled drug delivery;however, such an improvised system for systemic aspirin delivery exploring nanotechnology is not available. Systemic administration of aspirin and its controlled delivery can significantly control blood clotting events, leading to stroke, which has immediate applications in cardiovascular diseases and Covid-19. In this work, we are developing aspirin sustained release pegylated amphiphilic self-assembling nanoparticles to develop reconstitutable aspirin injections by solvent-based co-precipitation method with phase inversion technique that leads to novel "biomimetic niosomal nanoparticles (BNNs).” DOE led optimization is done to develop Design of space for optimized particles. Upon reconstitution of solid powder, the particle size was 144.8 ± 12.90 nm with a surface charge of -29.2 ± 2.24 mV. The entrapment efficiency was found to be 49 ± 0.15%, wherein 96.99 ± 1.57% of the drug was released in 24hr showing super case II transport-based drug release mechanism. The formulation has the least hemolysis while showing significant suppression of platelet aggregation. MTT assay does not show any significant cytotoxicity. This is a potential nanoparticle that can be explored for developing aspirin injection, which is not available.
ABSTRACT
Partitioning and effect of antiviral GC376, a potential SARS-CoV-2 inhibitor, on model lipid membranes was studied using dynamic light scattering (DLS), UV–VIS spectrometry, Excimer fluorescence, Differential scanning calorimetry (DSC) and Small- and Wide-angle X-ray scattering (SAXS/WAXS). Partition coefficient of GC376 between lipid and water phase was found to be low, reaching KP = 46.8 ± 18.2. Results suggest that GC376 partitions into lipid bilayers at the level of lipid head-groups, close to the polar/hydrophobic interface. Changes in structural and thermodynamic properties strongly depend on the GC376/lipid mole ratio. Already at lowest mole ratios GC376 induces increase of lateral pressures, mainly in the interfacial region of the bilayer. Hereby, the pre- and main-transition temperature of the lipid system increases, what is attributed to tighter packing of acyl chains induced by GC376. At GC376/DPPC ≥ 0.03 mol/mol we detected formation of domains with different GC376 content resulting in the lateral phase separation and changes in both, main transition temperature and enthalpy. The observed changes are attributed to the response of the system on the increased lateral stresses induced by partitioning of GC376. Obtained results are discussed in context of liposome-based drug delivery systems for GC376 and in context of indirect mechanism of virus replication inhibition.
ABSTRACT
Due to the high incidence of kidney disease, there is an urgent need to develop wearable artificial kidneys. This need is further exacerbated by the coronavirus disease 2019 pandemic. However, the dialysate regeneration system of the wearable artificial kidney has a low adsorption capacity for urea, which severely limits its application. Therefore, nanomaterials that can effectively remove uremic toxins, especially urea, to regenerate dialysate are required and should be further investigated and developed. Herein, flower-like molybdenum disulphide (MoS2) nanosheets decorated with highly dispersed cerium oxide (CeO2) were prepared (MoS2/CeO2), and their adsorption performances for urea, creatinine, and uric acid were studied in detail. Due to the open interlayer structures and the combination of MoS2 and CeO2, which can provide abundant adsorption active sites, the MoS2/CeO2 nanomaterials present excellent uremic toxin adsorption activities. Further, uremic toxin adsorption capacities were also assessed using a self-made fixed bed device under dynamic conditions, with the aim of developing MoS2/CeO2 for the practical adsorption of uremic toxins. In addition, the biocompatibility of MoS2/CeO2 was systematically analyzed using hemocompatibility and cytotoxicity assays. Our data suggest that MoS2/CeO2 can be safely used for applications requiring close contact with blood. Our findings confirm that novel 2-dimensional nanomaterial adsorbents have significant potential for dialysis fluid regeneration. © 2022
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Copper (Cu) was one of the first metals to be excavated and used by humans. Copper nanoparticles have a lot of attention due to their high electrical conductivity, high melting point, low electrochemical migration and low cost. It also demonstrated antiviral activity such as a recent study showing that the coronavirus survives for several days on glass, plate, and stain-less steel, but dies within a few hours on Cu. It is observed that controlling particle size expands the range of innumerable applications. Several methods have been employed for the synthesis of Cu nanoparticles such as Physical, Chemical, biological and green synthesis. In the present work, nanoparticles were successfully synthesized by a facile electrochemical deposition method. In which, Copper sulfate pentahydrate (CuSO4.5H2 O), is used as a pre-cursor and Sodium hydroxide (NaOH) used to maintain pH during the deposition in de-ionized water (DI) as a solvent. The structural and optical characterization of nanoparticles were performed by X-ray diffraction (XRD), Field effect Scanning Electron Microscope (FESEM), and UV-Vis Spectroscopy. The FCC structure of Cu nanoparticles has been analyzed by XRD and the size varies from 65 nm-30 nm by controlling pH of electrolyte solution. In the optical studies, it is observed that the bandgap is varying in the range of 2.98 eV to 4.97 eV, calculated by Tauc plot. © 2022. Lokesh et al.
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COVID-19 pandemic encourages the utilization of local food sources to ensure food availability. Busil (Xanthosoma sagittifolium) was readily available and affordable in Banjarnegara Regency in the Province of Central Java in Indonesia. However, the busil starch utilization was still rare due to the low functional properties of the native busil starch. The objective of this study was to explore busil starch physicochemical characterization enhancement after microwave irradiation treatment, especially on the stability of heat processing. This research was conducted in two steps. First, microwave treatment (with a variation of energy and irradiation time) of native busil starch (NBS), and the second was modified busil starch (MBS) physicochemical characterization. A rise in amylose was observed on MBS. SEM analysis was shown MBS granules are breakdown. Through viscosity, final viscosity, setback viscosity, peak time, and the pasting temperature of MBS generally were increased. Meanwhile, peak viscosity and breakdown viscosity of MBS was decreased. Thermal properties of MBS like onset (To), peak (Tp), and conclusion (Tc) temperatures were also increased. The degree of whiteness index (DW) of MBS was decreased. FTIR analysis has shown that microwave treatment did not cause functional group alteration. XRD analysis has also demonstrated no change in the diffraction pattern but a slight change in the crystallinity index. Generally, microwave treatment leads to MBS thermal stability and potentially broaden MBS utilization on food processing product.
ABSTRACT
The main substances of rice are starches, which vary their metabolism during storage. We conducted a series of tests including rice physicochemical properties, edible quality, starch content and chain length distribution along with starch structure variation to disclose the shift of rice quality by observing the changes of rice during storage. The results showed that: (1) the rice deterioration occurred as time passed, and the germination rate decreased from 70.8% to 29.4% during the storage;(2) fatty acid values increased significantly during long-term storage;(3) electrical conductivity increased as time passed;and (4) the two-year-storage rice showed significantly decreased viscosity and edible quality after sensory evaluation, decreased hardness and damaged surface area of starch granules as storage time passed. Additionally, the damaged surface area of starch granules increased with storage time. Fourier transform infrared spectroscopy (FTIR) showed that the short-range order and spiral degree of rice starch first decreased in the first year and then increased over the storage time. Furthermore, X-ray diffraction showed that the main starch of rice was A-type crystalline. Meanwhile, apparent amylose content increased from 31.00% to 33.85%, then decreased to 31.75%. The peak viscosity reduced from 2735.00 mPa·s to 2163.67 mPa·s and the disintegration value was brought down from 1377.67 mPa·s to 850.33 mPa·s. Based on the results, rice should not be stored for more than 2 years under suitable granary conditions to maintain it at a good quality.
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This paper examines the biological approach used to synthesize gold nanoparticles (AuNPs) by using Myrtus communis leaves extract as reducing agent and Chloroauric acid as precursors. Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) used in addition to UV-visible spectroscopy (UV) in order to characterize the AuNPs. The biosynthesized AuNPs exhibited inhibitory effects on ferritin and lactate dehydrogenase activity in sera of covid-19 patients and the sera of healthy control subjects;the inhibition percentage with LDH was 76.86% and 63% for patient and control group, respectively. While for ferritin activity, it was 85.85% for patient group and 75.18% for control group. Kinetic studies of ferritin and lactate dehydrogenase performed. Further studies on other biological activities were required to exploit AuNPs full potential. The goal of this study is to synthesized gold nanoparticles using simple, cheap and environmentally green method. This stage is more suited to large-scale manufacturing since it is speedy and removes the complex steps in other bio based methods (by using fungi and bacteria).
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Covid-19 was mainly treated by a broad-spectrum antiviral called Remdesivir. A truncated cone molecular structure of Hydroxypropyl-ß-cyclodextrin can enhance the solubility and cellular uptake of the poorly soluble drug's through biological membranes. This study aimed to synthesize, characterize, observe cellular uptake and evaluate the cytotoxicity of remdesivirhydroxypropyl-ß-cyclodextrin (RDV-HPßCD) inclusion complex. The RDV-HPßCD inclusion complex was synthesized by the solvent evaporation method. Furthermore, the inclusion complex characteristic was evaluated by ultraviolet-visible (UV-Vis) spectrophotometry;particle size analyzer (PSA);Fourier infrared spectrophotometry (FTIR);X-ray diffraction (XRD);and differential scanning calorimetry (DSC). Further, fluorescence microscopy was used to evaluate the cellular uptake and 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used in the cytotoxicity study. In the UV-Vis spectrum, both the inclusion complex and pure remdesivir showed a maximum peak at 246 nm. The inclusion complex has a particle size of 1697 ± 738.02 nm with -22.4 ± 1.58 mV of zeta potential. Shifted FTIR spectrum, broad XRD peak, and broad DSC thermogram peak at 72.93 °C indicated the successful formation of the RDV-HPßCD inclusion complex. Furthermore, cellular uptake observation of RDV-HPßCD inclusion complex conjugated to FITC showed better intensity inside the Vero cell than pure remdesivir conjugated to FITC. Further, Inclusion complex showed higher cell viability than pure remdesivir at a certain concentration.
ABSTRACT
While the new coronavirus has turned our lives upside down causing millions of deaths, the historically known tuberculosis (TB) disease caused by Mycobacterium tuberculosis (MTB) was responsible for the loss of approximately 1.5 million lives alone in 2021. New anti- TB drugs are in an urgent need. A promising target is dUTPase, an enzyme preventing uracil incorporation into DNA. It is present in all multicellular species and in most microbes. Abolition of its activity potentially leads to DNA double strand breaks and cell death. Therefore, species-specific inhibition of MTB dUTPase may be a successful way of TB disease treatment. Currently no species-specific dUTPase inhibitor exists, but an interaction partner, protein Stl shows significantly different ability to inhibit dUTPase homologues from various species. We use Stl as a model to understand how species- specific differences in dUTPase structure may be harnessed in future inhibitor development. A remarkable species-specific characteristic of MTB dUTPase is a small surface sequence loop playing no direct role in enzyme activity but being essential for mycobacterial survival in a yet unknown way. What is the exact structural background of MTB dUTPase-Stl interaction? For this reason, we have crystallized a complex of MTB dUTPase and a truncated Stl protein mutant. And how the loop sequence may affect the MTB dUTPase protein structure on its own? For this answer, we obtained another X-ray diffraction dataset of a loop-lacking mutant of MTB dUTPase with 1.3 Å resolution. Surprisingly, electron density of the flexible C-terminal “arm” segment of the mutant dUTPase was missing from our dataset, contrary to the already crystallized wildtypeMTB dUTPase structures. We postulate that the loop sequence may restrict conformational flexibility of the dUTPase “arm”, making it more inhibitable by Stl compared to the loop-lacking mutant, as we know from our comparative steady-state enzyme activity inhibition measurements.