Inhibition Of Enzyme Activity Research Articles

NIR Fluorescence Strategy for the Early Diagnosis of Melanoma Liver Metastasis Based on the Cascade Reaction of Two Specific Bioenzymes.

Melanoma liver metastasis poses a serious risk to patient health, leading to deterioration of liver function accompanied by symptoms such as jaundice, abdominal pain, and weight loss. Early detection is paramount as it allows for timely intervention, potentially improving treatment efficacy and patient outcomes. Herein, a dual-target probe activated by butyrylcholinesterase (BChE) and tyrosinase (TYR) was proposed by initiating an enzyme cascade reaction, revealing NIR-emissive methylene blue (MB) as a responsive product. The cascade reaction mechanism was confirmed by enzyme activity inhibition experiments and high-resolution mass spectrometry. Intercellular imaging was carried out on the coincubation model of Hep G2 and B16 cell lines, which is the first attempt to the best of our knowledge. The results showed that BChE expressed in liver cells and TYR overexpressed in B16 cells jointly activated NIR fluorescence, which provides the possibility for the precise detection of melanoma liver metastasis. In vivo studies further proved that this method holds promise for the early diagnosis and postoperative adjunctive therapy of hepatic melanoma, ultimately enhancing survival rates.

Strong Effects of Increased Hydrostatic Pressure on Polysaccharide‐Hydrolyzing Enzyme Activities in Coastal Seawater and Sediments

AbstractHeterotrophic microorganisms are responsible for transforming and respiring a substantial fraction of the organic matter produced by phytoplankton in the surface ocean. Much of this organic matter is composed of polysaccharides, high‐molecular weight (HMW) sugars. To initiate degradation of polysaccharides, microorganisms must produce extracellular enzymes of the right structural specificity to hydrolyze these complex structures. To date, most measurements of enzyme activities are made at in situ temperatures, but at atmospheric pressure. However, previous studies have shown that hydrostatic pressure can impact the functionality of enzymes. Since deep sea communities may be seeded by microbes from shallow waters, we aimed to determine if pressure affects the performance of enzymes from coastal waters. To determine the extent to which enzymatic activities of coastal microbial communities are affected by pressure, we quantified the degradation of seven polysaccharides under pressures ranging from 0.1 MPa (atmospheric) to 40 MPa (equivalent to 4,000 m). Enzyme activities of pelagic communities were inhibited with increased pressure, while enzyme activities of benthic microbial communities were more resistant to increased pressure. Addition of HMW organic matter resulted in communities with enzyme activities that were more resistant to increased pressure. However, the freely‐dissolved enzymes (<0.2 μm) produced by these communities were strongly inhibited by increased hydrostatic pressure, suggesting that the pressure‐resistant enzymes were cell‐surface attached. Because pressure inhibition of enzyme activities varied strongly by polysaccharide, we surmise that the structural complexity of a polysaccharide—and therefore the number of distinct enzymes required for hydrolysis—is likely closely associated with pressure inhibition.

Preservation Strategies for Interfacial Integrity in Restorative Dentistry: A Non-Comprehensive Literature Review

The preservation of interfacial integrity in esthetic dental restorations remains a critical challenge, with hybrid layer degradation being a primary factor in restoration failure. This degradation is driven by a combination of host-derived enzymatic activity, including matrix metalloproteinases (MMPs), bacterial proteases, and hydrolytic breakdown of the polymerized adhesive due to moisture exposure. This review examines the multifactorial mechanisms underlying hybrid layer degradation and presents current advancements in restorative materials aimed at counteracting these effects. Principal strategies include collagen preservation through the inhibition of enzymatic activity, the integration of antimicrobial agents to limit biofilm formation, and the use of ester-free, hydrolysis-resistant polymeric systems. Recent research highlights acrylamide-based adhesives, which exhibit enhanced resistance to acidic and enzymatic environments, as well as dual functionality in collagen stabilization. Furthermore, innovations in bioactive resins and self-healing materials present promising future directions for developing adhesives that actively contribute to long-term restoration stability. These findings underscore the importance of continuous advancements in adhesive technology to enhance the durability and clinical performance of dental restorations.

Identification of a Monovalent Pseudo-Natural Product Degrader Class Supercharging Degradation of IDO1 by its native E3 KLHDC3.

Targeted protein degradation (TPD) modulates protein function beyond inhibition of enzyme activity or protein-protein interactions. Most degrader drugs function by directly mediating proximity between a neosubstrate and hijacked E3 ligase. Here, we identified pseudo-natural products derived from (-)-myrtanol, termed iDegs that inhibit and induce degradation of the immunomodulatory enzyme indoleamine-2,3-dioxygenase 1 (IDO1) by a distinct mechanism. iDegs boost IDO1 ubiquitination and degradation by the cullin-RING E3 ligase CRL2 KLHDC3 , which we identified to natively mediate ubiquitin-mediated degradation of IDO1. Therefore, iDegs increase IDO1 turnover using the native proteolytic pathway. In contrast to clinically explored IDO1 inhibitors, iDegs reduce formation of kynurenine by both inhibition and induced degradation of the enzyme and, thus, would also modulate non-enzymatic functions of IDO1. This unique mechanism of action may open up new therapeutic opportunities for the treatment of cancer beyond classical inhibition of IDO1.

Integrated Physiological, Transcriptomic and Metabolomic Analyses of the Response of Rice to Aniline Toxicity.

The accumulation of aniline in the natural environment poses a potential threat to crops, and thus, investigating the effects of aniline on plants holds practical implications for agricultural engineering and its affiliated industries. This study combined physiological, transcriptomic, and metabolomic methods to investigate the growth status and molecular-level response mechanisms of rice under stress from varying concentrations of aniline. At a concentration of 1 mg/L, aniline exhibited a slight growth-promoting effect on rice. However, higher concentrations of aniline significantly inhibited rice growth and even caused notable damage to the rice seedlings. Physiological data indicated that under aniline stress, the membrane of rice underwent oxidative damage. Furthermore, when the concentration of aniline was excessively high, the cells suffered severe damage, resulting in the inhibition of antioxidant enzyme synthesis and activity. Transcriptomic and metabolomic analyses indicated that the phenylpropanoid biosynthesis pathway became quite active under aniline stress, with alterations in various enzymes and metabolites related to lignin synthesis. In addition to the phenylpropanoid biosynthesis pathway, amino acid metabolism, lipid metabolism, and purine metabolism were also critical pathways related to rice's response to aniline stress. Significant changes occurred in the expression levels of multiple genes (e.g., PRX, C4H, GST, and ilvH, among others) associated with functions such as antioxidant activity, membrane remodeling, signal transduction, and nitrogen supply. Similarly, notable alterations were observed in the accumulation of various metabolites (for instance, glutamic acid, phosphatidic acid, phosphatidylglycerol, and asparagine, etc.) related to these functions. Our research findings have unveiled the potential of compounds such as phenylpropanoids and amino acids in assisting rice to cope with aniline stress. A more in-depth and detailed exploration of the specific mechanisms by which these substances function in the process of plant resistance to aniline stress (for instance, utilizing carbon-14 isotope tracing to monitor the metabolic pathway of aniline within plants) will facilitate the cultivation of plant varieties that are resistant to aniline. This will undoubtedly benefit activities such as ensuring food production and quality in aniline-contaminated environments, as well as utilizing plants for the remediation of aniline-polluted environments.

Fabrication of tannins and oat protein non-covalent complexes: Effect on the structure and in vitro digestion properties of oat proteins.

This study explored the non-covalent interactions between oat protein isolate (OPI) and two tannic compounds-proanthocyanidins (PA) and tannic acid (TA)-and examined their impact on the structural and digestive properties of oat proteins. The combination of OPI with tannic compounds formed granular complexes with particle sizes ranging from 126 to 240 nm and zeta potentials between -35 and -44 mV. Compared to OPI alone, the α-helix and β-turn contents decreased, while the β-sheet and random coil contents increased in both OPI-tannin complexes. Fluorescence spectra analysis indicated that hydrogen bonding was the main interaction force in OPI-PA complexes, while OPI and TA were primarily bound by hydrophobic interactions. The simulated digestion analysis showed that the protein digestibility was delayed in the OPI-tannin complexes, likely due to the inhibition of digestive enzyme activity by tannic compounds, which slowed OPI digestibility. Additionally, the oxidation resistance of the OPI-tannin complexes significantly improved after in vitro digestion, indicating that the non-covalent complexes provided superior protection for the tannic compounds. These findings offer theoretical support for the design and utilization of oat- and tannin-rich foods.

Critical considerations for co-administering rivaroxaban and vonoprazan: unveiling potential pharmacokinetic interactions

To study the effects of metabolic enzyme activity inhibition and genetic polymorphisms on the pharmacokinetics and pharmacodynamics of rivaroxaban, we established an in vitro enzymatic reaction system to screen for inhibitors, and used the UPLC-MS/MS method to detect the levels of rivaroxaban and its metabolite M2-1. Additionally, in vivo pharmacokinetic-pharmacodynamic studies were conducted using Sprague-Dawley rats. Human recombinant CYP2J2 baculosomes were prepared using a baculovirus-insect expression system to investigate the impact of genetic polymorphisms on rivaroxaban metabolism through enzyme kinetics methods. The results demonstrated that acid-suppressing drugs strongly inhibited the metabolism of rivaroxaban in vitro. Among them, vonoprazan significantly increased the systemic exposure of rivaroxaban in vivo, while also prolonging prothrombin time, likely due to the competitive binding of vonoprazan and rivaroxaban to CYP2J2. Moreover, the genetic polymorphisms of CYP2J2 determined the metabolic characteristics of rivaroxaban and the inhibitory potency of vonoprazan. Overall, our findings suggest that vonoprazan-induced inhibition of CYP2J2 activity can affect the pharmacokinetics and pharmacodynamics of rivaroxaban, with the extent of inhibition determined by the genetic polymorphism of CYP2J2. These insights have important implications for the precise management of rivaroxaban in humans.

Fatty Acid Oxidation-Glycolysis Metabolic Transition Affects ECM Homeostasis in Silica-Induced Pulmonary Fibrosis.

Silicosis is a fatal occupational pulmonary disease that is characterized by irreversible replacement of lung parenchyma by aberrant Exracellular matrix (ECM). Metabolic reprogramming is a crucial mechanism for fibrosis. However, how the metabolic rewiring shifts the ECM homeostasis toward overaccumulation remains unclear. Herein, a phenotype with reduction in fatty acid oxidation(FAO) but enhanced glycolysis in myofibroblasts is shown. Perturbation of the glycolytic and FAO pathways, respectively, reveals distinct roles in the metabolic distribution of ECM deposition and degradation. Suppressed glycolysis leads to a decrease in insoluble ECM, primarily due to the inhibition of ECM-modifying enzyme activity and a decrease in glycine synthesis. Notably, promoted FAO facilitates the intracellular degradation pathway of ECM. In addition, the findings revealed that hypoxia-inducible factor-1 alpha (HIF-1α) serves as a crucial metabolic regulator in the transition from FAO to glycolysis, thereby playing a significant role in ECM deposition in silica-induced pulmonary fibrosis. Further, the promotion of FAO, inhibition of glycolysis and HIF-1α reduce ECM production and promote ECM degradation, ultimately impeding the progression of fibrosis and providing therapeutic relief for established pulmonary fibrosis in vivo. These findings unveil the metabolic rewire underpinning the deposition of ECM in silica-induced lung fibrosis and identify novel targets for promoting regression of pulmonary fibrosis.

The effect of synergists on the inhibition of detoxification enzyme activities and acaricide sensitivity in Rhizoglyphus robini.

The saffron bulb mite, Rhizoglyphus robini Claparede (Acari: Acaridae), is the most important pest of the saffron crop in Iran. This pest attacks and feeds on saffron corms. For this reason, the corms are treated with acaricides before planting. The high activity of detoxification enzymes in arthropods may reduce their pesticide sensitivity. Diethyl maleate (DEM) is an inhibitor of glutathione S-transferases (GSTs), piperonyl butoxide (PBO) is an inhibitor of cytochrome P450 monooxygenases, and triphenyl phosphate (TPP) is an inhibitor of esterase activity. A filter paper method was used to determine the efficiency of these synergists in inhibiting the activity of detoxifying enzymes of R. robini. Adult mites were treated with these three synergists for 6, 12, 24, and 48 h, respectively. The activity of each detoxifying enzyme was measured and compared to the control treatment, and the inhibition percentage was calculated each time. The results showed that DEM reduced GST activity by 59.9% after 48 h, PBO inhibited cytochrome P450 activity by 30%, and TPP suppressed esterase activity by 38.5%. The most statistically significant inhibition occurred 24 h after pretreatment with each synergist. Bioassays with 24 h pretreatment showed that the sensitivity of R. robini to propargite increased by 1.6 times with PBO, 1.7 times with TPP, and 2.5 times with DEM. In conclusion, synergists and efficient inhibition of detoxifying enzymes can play a significant role in increasing the sensitivity of agricultural pests to pesticides and can be considered in managing pesticide resistance.

Effect of oil and diesel fuel pollution on enzymatic activity of meadow chernozem-like soil

In the laboratory experiment, the effect of oil pollution on the short-term dynamics of the activity of urease, phosphatase, catalase, peroxidase and polyphenol oxidase of the chernozem soil of the south of the Far East was studied. It was found that when soil was contaminated with oil and petroleum products, urease activity decreased by 20–44% at the end of incubation, peroxidase activity increased by 39–49% in the middle and end of incubation, polyphenol oxidase activity increased 1.6–2.0 times in the middle of incubation. The activity of phosphatase and catalase was stable at different levels of contamination throughout the experiment. Examining the effect of the incubation period, it was found that the maximum activity of urease was on the 10th day, phosphatase – on the 20th, peroxidase – on the 20th and 30th, polyphenol oxidase – on the 30th day of the experiment. Catalase activity was stable throughout all incubation periods. It was shown that in the case of contamination of chernozem-like soil with oil and diesel fuel in doses up to 5000 mg/kg, inhibition of enzymatic activity did not occur in the early stages.

Abstract PR003: Structure-guided design and optimization of small molecule CD73 inhibitors with excellent drug-like properties: discovery of quemliclustat

Abstract In the tumor microenvironment, high concentrations of extracellular adenosine promote tumor proliferation through various immunosuppressive mechanisms. High expression of CD73—an ecto-nucleotidase that produces adenosine from adenosine monophosphate—has been associated with poorer prognosis in several tumor types. Herein, we describe the drug discovery efforts that resulted in the discovery of quemliclustat, a highly potent and selective inhibitor of CD73. As a small molecule with excellent drug-like properties, quemliclustat offers several advantages over CD73 antibodies in development, such as greater inhibition of CD73 enzymatic activity (both soluble and membrane-bound), deeper tumor penetration, and the potential for both IV and oral formulations. Quemliclustat was the first small molecule CD73 inhibitor to enter clinical development and is currently being evaluated in various Phase 1/2 studies in advanced solid tumors, including lung and pancreatic cancers. Recent data in metastatic pancreatic cancer are supportive of further study in this disease setting. Citation Format: Jenna Jeffrey Structure-guided design and optimization of small molecule CD73 inhibitors with excellent drug-like properties: discovery of quemliclustat. [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Optimizing Therapeutic Efficacy and Tolerability through Cancer Chemistry; 2024 Dec 9-11; Toronto, Ontario, Canada. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(12_Suppl):Abstract nr PR003

Antifungal activity of bamemacrolactine C against Talaromyces marneffei and its possible mechanisms of action.

The present study aims to investigate the in vitro antifungal activity and mechanism of action of bamemacrolactine C (BAC), a new 24-membered macrolide compound, against Talaromyces marneffei. The test drug BAC initially demonstrated antifungal activity through a paper disk diffusion assay, followed by determination of the minimum inhibitory concentration value of 35.29 μg ml-1 using microdilution. The association study revealed that combination therapy exhibited additive effects (0.5 < FICI < 1.0) when combined BAC with either amphotericin B or fluconazole. A time-growth assay confirmed that treatment with 35.29 μg ml-1 of BAC completely inhibited the growth of T. marneffei and exhibited antifungal effects. Micromorphological analysis using scanning electron microscopy and transmission electron microscopy photomicrographs revealed that BAC treatment induced morphological damage in fungal cells compared to the control group. Transmembrane protein assays showed a significant reduction in the levels of Na+/K+-ATPase (P < .05) and Ca2+-ATPase (P < .01) compared to the control group. Intracellular enzyme assays demonstrated that BAC treatment significantly decreased ATP, malate dehydrogenase, and succinate dehydrogenase content (P < .01). The combination of proteomics and parallel reaction monitoring (PRM) verification indicated that BAC exhibits an antifungal mechanism against T. marneffei by downregulating ATP citric acid lyase (ACLY) levels , potentially affecting the tricarboxylic acid (TCA) cycle. Besides, the binding model of BAC and the ACLY also shows a good docking score. The findings suggest that BAC exhibits antifungal activity against T. marneffei, elucidating its multifaceted mechanism of action involving disruption of cell membranes' integrity and inhibition of intracellular enzyme activities, in which the modulation of ACLY in the TCA cycle may play an important role.

A Potent, Selective, Small-Molecule Inhibitor of DHX9 Abrogates Proliferation of Microsatellite Instable Cancers with Deficient Mismatch Repair.

DHX9 is a multifunctional DExH-box RNA helicase with important roles in the regulation of transcription, translation, and maintenance of genome stability. Elevated expression of DHX9 is evident in multiple cancer types, including colorectal cancer (CRC). Microsatellite instable-high (MSI-H) tumors with deficient mismatch repair (dMMR) display a strong dependence on DHX9, making this helicase an attractive target for oncology drug discovery. In this report, we show that DHX9 knockdown increased RNA/DNA secondary structures and replication stress, resulting in cell cycle arrest and the onset of apoptosis in cancer cells with MSI-H/dMMR. ATX968 was identified as a potent and selective inhibitor of DHX9 helicase activity. Chemical inhibition of DHX9 enzymatic activity elicited similar selective effects on cell proliferation as seen with genetic knockdown. In addition, ATX968 induced robust and durable responses in an MSI-H/dMMR xenograft model but not in a microsatellite stable (MSS)/proficient mismatch repair (pMMR) model. These preclinical data validate DHX9 as a target for the treatment of patients with MSI-H/dMMR. Additionally, this potent and selective inhibitor of DHX9 provides a valuable tool with which to further explore the effects of inhibition of DHX9 enzymatic activity on the proliferation of cancer cells in vitro and in vivo.

Recent discoveries of propyl gallate restore the antibacterial effect of tigecycline against tet(X4)-positive Escherichia coli

Propyl gallate (PG), an approved food additive, can be added to different foods and drugs to provide health benefits with minimal danger. However, no clinical application of PG as an antibacterial agent for the treatment of antimicrobial resistance (AMR) has been documented. The aim of this study was to elucidate the effects and mechanisms by which PG inhibits the activity of Tet(X4). Enzyme activity inhibition assay, antimicrobial tests, scanning electron microscopy (SEM) assay, molecular docking and dynamics simulation assays, and animal infection models were used to confirm the synergistic efficacy and mechanism. Here, we found that PG efficiently inhibited Tet(X4) enzyme activity (IC50 = 34.83 μg/mL) while affecting the expression of tet(X4). PG has a synergistic effect with tigecycline (fractional inhibitory concentration index (FICI) < 0.5) against tet(X4)-positive Escherichia coli (E. coli) isolates of animal origin. The survival rates of G. mellonella larvae and the mouse systemic infection model increased by 60 % and 39 %, respectively. The combination of PG and tigecycline showed remarkable treatment benefits in terms of the bacterial load and inflammatory factors in mice. Our results indicate that PG is a valuable adjuvant with tetracyclines and can be considered to address the inevitable infection caused by tet(X4)-positive bacteria, which is a feasible way to extend the lifespan of existing antibiotics.

Discovery of α-amylase and α-glucosidase dual inhibitors from NPASS database for management of Type 2 Diabetes Mellitus: A chemoinformatic approach.

Postprandial hyperglycemia, typical manifestation of Type 2 Diabetes Mellitus (T2DM), is associated with notable global morbidity and mortality. Preventing the advancement of this condition by delaying the rate of glucose absorption through inhibition of α-amylase and α-glucosidase enzymatic activities is of utmost importance. Finding a safe antidiabetic drug is essential since those that are currently on the market have drawbacks like unpleasant side effects. The current study utilized computer-aided drug design (CADD), as a quick and affordable method to find a substitute drug template that can be used to control postprandial hyperglycemia by modulating the activity of α-amylase and α-glucosidase enzymes. The Natural Products Activity and Species database (NPASS) (30,926 compounds) was screened in silico, with a focus on evaluating drug-likeness, toxicity profiles and ability to bind on a target protein. Two molecules NPC204580 (Chrotacumine C) and NPC137813 (1-O-(2-Methoxy-4-Acetylphenyl)-6-O-(E-Cinnamoyl)-Beta-D-Glucopyranoside) were identified as potential dual inhibitors for α-amylase and α-glucosidase with free binding energies of -14.46 kcal/mol and -12.58 kcal/mol for α-amylase, and -8.42 kcal/mol and -8.76 kcal/mol for α-glucosidase, respectively. The molecules showed ionic, H-bonding and hydrophobic interactions with critical amino acid residues of both enzymes. Moreover, 100 ns molecular dynamic simulations showed that both molecules are stable on the receptors' active sites based on root mean square deviation (RMSD), root mean square fluctuation (RMSF), and the Generalized Born surface area (GBSA) energy calculated. The two compounds are thus promising therapeutic agents for T2DM that merit further investigation due to their excellent binding energies, encouraging pharmacokinetics, toxicity profiles, and stability as demonstrated in simulated studies.

The molecular reactive pathway between lipoxygenase and lipase and reactive species generated in dielectric barrier discharge atmospheric cold plasma: An investigation using molecular docking

The molecular docking was explored to study the interactions between reactive species generated by cold plasma and the enzymes lipoxygenase (LOX) and lipase (LPS), with the aim of elucidating the molecular mechanisms governing these interactions. Molecular docking results suggest that both LOX and LPS are primarily involved in hydrogen bonding interactions with the seven reactive species. The key binding sites for LOX and LPS were identified as Ile 663 and Glu 188, respectively. Notably, the lowest docking energy was observed between LOX and NO (−13.75 kcal/mol), whereas for LPS, it is between LPS and NO3 (−12.08 kcal/mol). Increased treatment voltage and time resulted in higher inactivation levels, with LPS exhibiting higher residual activity compared to LOX. When the voltage was 75 kV and the time was 120 s, the residual activities of LOX and LPS were 42.88% and 56.77%, respectively. Consequently, the results enhance our understanding of the mechanisms underlying the inhibition of enzyme activity by reactive species generated by cold plasma. Moreover, cold plasma may serve as a novel preservation technology for inhibiting lipid oxidation of food by controlling enzyme activity.

Exposure to organophosphate insecticides induces behavioral changes and acetylcholinesterase inhibition in Apis mellifera

European honey bee (Apis mellifera L.) is an essential pollinator that contributes significantly to the global ecosystem and agricultural productivity. However, their population has been facing unprecedented threats, primarily due to their exposure to various pesticides, including organophosphates. These pesticides are being widely used in agriculture to control insect pests due to their efficacy, but their non-selective nature raises concerns about their impact on honey bees. Insecticides viz., chlorpyriphos 20 Emulsifiable Concentrate, dimethoate 30 Emulsifiable Concentrate, and profenophos 50 Emulsifiable Concentrate at a range of 0.005–0.09 per cent concentration were evaluated through two modes of application viz., topical and oral. Acetylcholinesterase (AChE) activity was measured at various intervals (1 and 24 hours) to assess enzyme inhibition. Behavioral observations and statistical analyses, including factor analysis with Eigen values, were employed to evaluate the impact of exposure on bee behavior and physiological responses.The results revealed two factors with Eigen value > 0.95 in both topical as well as oral method which accounted for 88.28 and 88.80 per cent of the variation in behaviour, respectively. Insecticides applied to honey bee A. mellifera in both topical as well as oral methods resulted in significant inhibition of the Acetyl choline esterase enzyme (AChE) activity. Studies revealed higher AChE inhibition (%) in oral method as compared to topical method. AChE inhibition percentage increased from 25.15 (1 Hour after treatment) to 58.25 (24 Hours after treatment) with lower concentration (0.005) of chlorpyriphos in topical method while as it reached from 27.66 to 60.94 with same concentration and same time in oral method of application. AChE inhibition percentage increased from 35.81 (1 Hour after treatment) to 78.30 (24 Hours after treatment) with higher concentration (0.06) of chlorpyriphos in topical method while as it reached from 40.35 to 80.18 with same concentration and same time in oral method. Similar trend was observed in dimethoate, and profenophos where AChE inhibition increased from 17.30, 27.15 (1 Hour after treatment) to 57.18, 61.81 (24 Hours after treatment), respectively in topical method and 20.67, 28.80 (1 Hour after treatment) to 59.85 64.04 (24 Hours after treatment), respectively in oral method. Similarly, with higher concentrations of dimethoate (0.07), and profenophos (0.09), per cent inhibition increased from 34.54, 38.60 (1 Hour after treatment) to 75.68, 79.62 (24 Hours after treatment), in topical method and 37.25, 41.23 (1 Hours after treatment) to 77.86, 82.73 (24 Hours after treatment), in oral method, respectively. Thorough risk assessments are vital for evaluating the effects of agrochemicals on Apis mellifera. The findings highlight the necessity for updated pesticide regulations and broadened conservation strategies that take into account the diverse ways pollinators are exposed to agrochemicals in the environment. The study assessed the impact of different insecticides on Apis mellifera by comparing topical and oral exposure methods. The study also aimed to analyze the behavioral effects of insecticide exposure on Apis mellifera, assessing variations in response and enzyme inhibition.The research focused on evaluating Acetylcholinesterase (AChE) inhibition to better understand the risks posed to honeybees in agricultural environments.

Enzyme Activity Inhibition of α-Amylase Using Molecularly Imprinted Polymer (MIP) Hydrogel Microparticles.

Molecularly imprinted polymers (MIPs) are a class of synthetic recognition materials that offer a cost-effective and robust alternative to antibodies. While MIPs have found predominant use in biosensing and diagnostic applications, their potential for alternative uses, such as enzyme inhibition, remains unexplored. In this work, we synthesized a range of acrylamide-based hydrogel MIP microparticles (35 μm) specific for the recognition of α-amylase. These MIPs also showed good selectivity toward the target protein with over 96% binding of the target protein, compared with the control nonimprinted polymer (NIP) counterparts. Specificity of the MIPs was determined with the binding of nontarget proteins, trypsin, human serum albumin (HSA), and bovine serum albumin (BSA). The MIPs were further evaluated for their ability to inhibit α-amylase enzymatic activity, showing a significant decrease in activity. These findings highlight the potential of MIPs as enzyme inhibitors, suggesting an innovative application beyond their conventional use.

Targeting threonine deaminase with chiral Au NPs: A novel strategy for E. coli inhibition

Bacterial infections are becoming a significant threat to global human health due to the growing prevalence of biofilm-related infections and the rise in antibiotic resistance. D/l-cysteine functionalized chiral gold nanoparticles (D/P-Au NPs or L/P-Au NPs) have demonstrated a potent antibacterial effect against E. coli, while the mechanism remains to be elucidated through additional research. Threonine deaminase (TD) is a crucial enzyme involved in branched-chain amino acid (BCAA) biosynthesis in E. coli and is involved in cysteine's antimicrobial effects. This study investigated the interaction between chiral Au NPs (D/P-Au NPs or L/P-Au NPs) and TD as well as its effect on enzyme activity. It demonstrates that chiral Au NPs interact with TD through hydrophobic forces, forming a ground state complex that induces changes in the secondary structure of TD and reduces enzyme activity in a concentration-dependent manner. We found that the exogenous supplementation of isoleucine and valine (2 mg/mL) significantly reduced the antibacterial activity of chiral Au NPs, especially for L/P-Au NPs. The proteomics results indicate that the expression of ilvA and ilvB was down-regulated after L/P-Au NPs treatment, which would interfere with the synthesis of BCAAs. These results demonstrate that chiral Au NPs cause cell death of E. coli partly due to inhibition of TD enzyme activity and the synthesis of branched-chain amino acids.

Investigating The Synergistic and Antimicrobial Effect of Glycolipid Biosurfactants Produced by &lt;i&gt;Shewanella alga&lt;/i&gt; 12B and &lt;i&gt;Bacillus pumilus SG&lt;/i&gt; Bacteria with Thyme Plant Extract on Some Pathogenic Bacteria

Background: Thyme is widely recognized for its antimicrobial properties, attributed to the effective compounds present in its extract that inhibit and destroy pathogenic bacteria. Objectives: This study explores the impact of combining thyme extract with biosurfactants on pathogenic bacteria and biofilm. The biosurfactants 12B and SG have inherent antimicrobial effects, and their combination with thyme extract demonstrated synergistic effects. Methods: The experiments involved preparing methanolic thyme extract in combination with biosurfactants 12B and SG. Disk diffusion and well diffusion tests were conducted to assess the antimicrobial activity of this combination. The inhibition zones for Acinetobacterbaumannii, Bacilluscereus, Escherichiacoli, and methicillin-resistant Staphylococcusaureus (MRSA) were measured. Further tests determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for these bacteria. To evaluate synergistic effects, the fractional inhibitory concentration (FIC) and fractional inhibitory concentration index (FICI) were calculated. Results: The anti-biofilm effects of the biosurfactants combined with thyme extract were analyzed by testing biofilm formation inhibition, biofilm destruction, and inhibition of dehydrogenase enzyme activity within the biofilm. Biofilm assays were conducted using microplates, with readings taken at 490 nm using an ELISA reader. Conclusions: The biofilm tests demonstrated the effectiveness of thyme extract combined with biosurfactants. The results indicated that this combination exhibits antibacterial, anti-biofilm, and synergistic effects, making it effective against both antibiotic-resistant and non-resistant pathogenic bacteria.