Esterase Enzyme Research Articles

The effect of sublethal doses of flupyradifurone on the life table and esterase enzyme of Myzus persicae (Sulzer, 1776) (Hemiptera: Aphididae)

The aim of this study was to determine the effect of two different sublethal doses (LC10 and LC30) of flupyradifurone on the life table and esterase enzyme of Myzus persicae (Sulzer, 1776) (Hemiptera: Aphididae). The experiments were conducted in 2022 in Isparta University of Applied Sciences laboratory and climate rooms in 2022 as 1 control + 2 sublethal doses. For the life table, control, LC10 and LC30 doses were established as 30, 25 and 30 replications, respectively. Female and total lifespan of M. persicae adults exposed to LC10 concentrations of flupyradifurone were significantly shortened. Daily and total numbers of the offsprings decreased at both LC10 and LC30 concentrations. Furthermore, these negative effects on the aphid were revealed as a lower intrinsic rate of increase (r), net reproductive rate (R0), finite rate of increase (λ) and fecundity (F). Based on the obtained data, flupyradifurone seems to suppress the population growth of M. persicae. It was determined that esterase enzyme activity involved in pesticide detoxification did not change in populations exposed to two different sublethal doses of flupyradifurone and unexposed (control). It is thought that this study facilitates the understanding of the lethal and sublethal effects of flupyradifurone on aphid performance.

Searching for new plastic-degrading enzymes from the plastisphere of alpine soils using a metagenomic mining approach.

Plastic materials, including microplastics, accumulate in all types of ecosystems, even in remote and cold environments such as the European Alps. This pollution poses a risk for the environment and humans and needs to be addressed. Using shotgun DNA metagenomics of soils collected in the eastern Swiss Alps at about 3,000 m a.s.l., we identified genes and their proteins that potentially can degrade plastics. We screened the metagenomes of the plastisphere and the bulk soil with a differential abundance analysis, conducted similarity-based screening with specific databases dedicated to putative plastic-degrading genes, and selected those genes with a high probability of signal peptides for extracellular export and a high confidence for functional domains. This procedure resulted in a final list of nine candidate genes. The lengths of the predicted proteins were between 425 and 845 amino acids, and the predicted genera producing these proteins belonged mainly to Caballeronia and Bradyrhizobium. We applied functional validation, using heterologous expression followed by enzymatic assays of the supernatant. Five of the nine proteins tested showed significantly increased activities when we used an esterase assay, and one of these five proteins from candidate genes, a hydrolase-type esterase, clearly had the highest activity, by more than double. We performed the fluorescence assays for plastic degradation of the plastic types BI-OPL and ecovio® only with proteins from the five candidate genes that were positively active in the esterase assay, but like the negative controls, these did not show any significantly increased activity. In contrast, the activity of the positive control, which contained a PLA-degrading gene insert known from the literature, was more than 20 times higher than that of the negative controls. These findings suggest that in silico screening followed by functional validation is suitable for finding new plastic-degrading enzymes. Although we only found one new esterase enzyme, our approach has the potential to be applied to any type of soil and to plastics in various ecosystems to search rapidly and efficiently for new plastic-degrading enzymes.

Cognition enhancing activity of essential oil of Hedychium coronarium j. Koenig in memory-impaired animal models

Alzheimer's disease (AD) is a degenerative neurological condition that causes loss of memory and cognition. Numerous variables, such as age, environment, lifestyle, and genetics, influence the occurrence of such neurodegenerative diseases. Hedychium coronarium j. Koenig is being used traditionally for various skin problems. In, this study, we evaluated the effect of the anticholinesterase and antioxidant activity of the essential oil of Hedychium coronarium j. Koenig by in vitro as well as in vivo tests in Aluminum chloride (AlCl3) induced zebrafish and mouse models of memory impairment. Hedychium coronarium j. Koenig significantly retained the spatial and fear memory in zebrafish and mice. Oral administration of the essential oil of Hedychium coronarium j. Koenig has neuroprotective effects in the pathogenesis of Alzheimer's disease by regulating lipid peroxidation and reducing oxidative stress in the brains of Aluminum chloride-treated mice and zebrafish, according to biochemical and histopathological studies. These findings suggest that Hedychium coronarium j. Koenig essential oil has anti-amnesic effects via acetylcholine esterase enzyme inhibition and modulation of oxidative stress indicators in neuronal cells. As a result, the current research also suggests that Hedychium coronarium j. Koenig may be used as a natural, complementary therapy for cognitive problems linked to Alzheimer's disease (AD).

The Rise of Remimazolam: A Review of Pharmacology, Clinical Efficacy, and Safety Profiles.

Anesthesiologists often use benzodiazepines (BZDs) due to their remarkable amnestic and anxiolytic capabilities. Because of this, they are perfect for use during the perioperative phase, when patients' anxiety levels are already high. Remimazolam has replaced certain commonly used intravenous (IV) anesthetics due to its excellent safety profile, rapid onset of action, and short half-life. The four classes of BZDs, 2-keto-benzodiazepines, 3-hydroxy-benzodiazepines, triazolobenzodiazepines, and 7-nitro-benzodiazepines based on chemical structure, provide various levels of drowsiness, forgetfulness, and anxiolysis. Based on their elimination half-life, short-acting BZDs typically have a half-life ranging from one to 12 hours, e.g., oxazepam; intermediate-acting BZDs have an average elimination half-life of 12 to 40 hours, e.g., alprazolam; and long-acting BZDs have an average elimination half-life of more than 40 hours, e.g., diazepam. The chloride ion channel is conformationally shifted by the benzodiazepine molecule resulting in central nervous system (CNS) inhibition and hyperpolarization. Each type of benzodiazepine has a favored use. For example, diazepam is used to treat anxiety. Midazolam is used for its anxiolytic and anterograde amnestic effects during the perioperative phase. Anxiety and epilepsy are two conditions that lorazepam effectively treats. There are now phase II and III clinical studies investigating remimazolam. It is not sensitive to alterations in its surroundings and has a brief half-life so that it may be removed rapidly, even after extensive infusion. Being a soft drug means the body easily breaks it down via metabolism, which explains many features. Remimazolam is hydrolyzed into methanol and its carboxylic acid metabolite CNS 7054 by esterase metabolism. Therefore, remimazolam has a shorter onset time and faster recovery than other BZDs. Remimazolam is metabolized independently of any particular organ. Patients with hepatic and renal problems will not see any changes in metabolism or excretion since the drug's ester moiety makes it a substrate for general tissue esterase enzymes. Like its predecessor, midazolam, it has a high potential for addiction. Some side effects that could occur during infusion include headaches and drowsiness. In clinical trials, hypotension, respiratory depression, and bradycardia were noted in participants. BZDs are helpful when used in conjunction with anesthesia. Remimazolam stands out, thanks to its unique pharmacokinetics, pharmacodynamics, safety profile, and potential medical applications. Its desirable properties make it a potential surgical premedication and sedative in the critical care unit. Anesthesiologists and other doctors could have access to more consistent and safer medication. However, additionalcomprehensive clinical trials are necessary to understand remimazolam's advantages and disadvantages.

Enhancing postharvest quality and extending storage life of Booth 7 avocado (Persea americana Mill.) fruit through sodium nitroprusside (SNP) application during low-temperature storage

Postharvest quality plays a crucial role in marketability, consumer acceptability, and shelf life of avocados. This study investigates the efficacy of nitric oxide (NO) on postharvest physiology and quality of Booth 7 avocados treated with different concentrations of sodium nitroprusside (SNP) - a nitric oxide-releasing compound. Booth 7 avocados were immersed in SNP solutions (0.5 mM, 1.0 mM, and 1.5 mM), while the control fruit was immersed in distilled water for 15 min. After treatment, the fruit was stored at a temperature (T) of 8 ± 1 °C and relative humidity (RH) of 90 ± 5% for 35 days, during which the control fruit exhibited complete deterioration. The results revealed that Booth 7 avocados treated with 1.5 mM SNP concentration exhibited delayed quality changes during storage, reduced ethylene production and respiration rate, reduced alterations in soluble solids and acid content of the fruit flesh, as well as delayed changes in flesh and peel color. Additionally, the activity of total phenolic compounds (TPC), polygalacturonase (PG), and polyphenol oxidase (PPO) enzymes increased significantly, while the activity of the pectin methyl esterase (PME) enzyme was reduced. In conclusion, SNP treatment improved the quality and can be utilized as a potential postharvest preservative for Booth 7 avocados. For producers and distributors, the use of SNP in avocado postharvest management offers the potential to extend shelf life without compromising fruit quality.

Link of Serum Esterase Enzymes with Cognitive Impairment in Diabetic Patients

Cognitive impairment is one of the main complications of diabetes and patients with cognitive impairment are considered to be in an intermediate stage of decreased cognition with higher risk of developing dementia and Alzheimer's disease. This study aimed at evaluating serum activity of two esterase enzymes including cholinesterase and paraoxonase 1 (PON 1) in diabetic patients and association with cognitive performance and metabolic parameters. In this crosssectional study, 128 diabetic patients were enrolled. Cognitive performance was evaluated using the Wechsler Adult Intelligence Scale-Revised (WAIS-R). Body mass index, fasting blood glucose, fasting blood insulin, insulin resistance, serum cholinesterase and paraoxonase 1 activity were measured. Prevalence of cognitive impairment was found to be 77% in the study population. Serum cholinesterase activity was found to be higher in diabetic patients with cognitive impairment than the patients with normal cognitive performance (p < 0.04). Further, a negative correlation was found between cognitive performance and cholinesterase activity, albeit statistically non-significant. Alteration in the activity of cholinesterase enzyme was shown to be associated with cognitive impairment in diabetic patients and future studies are required to find the pathophysiological mechanisms of diabetic cognitive dysfunction.

Microbial degradation of low-density polyethylene, polyethylene terephthalate, and polystyrene by novel isolates from plastic-polluted environment.

Biodegradation is an eco-friendly measure to address plastic pollution. This study screened four bacterial isolates that were capable of degrading recalcitrant polymers, i.e., low-density polyethylene, polyethylene terephthalate, and polystyrene. The unique bacterial isolates were obtained from plastic polluted environment. Dermacoccus sp. MR5 (accession no. OP592184) and Corynebacterium sp. MR10 (accession no. OP536169) from Malaysian mangroves and Bacillus sp. BS5 (accession no. OP536168) and Priestia sp. TL1 (accession no. OP536170) from a sanitary landfill. The four isolates showed a gradual increase in the microbial count and the production of laccase and esterase enzymes after 4weeks of incubation with the polymers (independent experiment set). Bacillus sp. BS5 produced the highest laccase 15.35 ± 0.19 U/mL and showed the highest weight loss i.e., 4.84 ± 0.6% for PS. Fourier transform infrared spectroscopy analysis confirmed the formation of carbonyl and hydroxyl groups as a result of oxidation reactions by enzymes. Liquid chromatography-mass spectrometry analysis showed the oxidation of the polymers to small molecules (alcohol, ethers, and acids) assimilated by the microbes during the degradation. Field emission scanning electron microscopy showed bacterial colonization, biofilm formation, and surface erosion on the polymer surface. The result provided significant insight into enzyme activities and the potential of isolates to target more than one type of polymer for degradation.

Unravel the Supremacy of Klebsiella variicola over Native Microbial Strains for Aroma-Enhancing Compound Production in Reconstituted Tobacco Concentrate through Metagenomic Analysis.

Sensory attributes strongly influence consumers' preferences for products. The inoculation of the Klebsiella variicola H8 strain in a reconstituted tobacco leaf concentrate (RTLC) solution increased neutral aroma-enhancing compound (NAEC) production by 45%, decreased the nicotine level by 25%, decreased the water-soluble total sugar content by ~36%, and improved the sensory quality by 5.71%. The production of NAECs such as dihydrokiwi lactone (DHKL: 192.86%), 1,2,3,4-tetrahydro-1,1,6-trimethylnaphthalene (THTMN: 177.77%), 2,4-di-tert-butylphenol (DTBP: 25%), 4-oxoisofolkone (OIFK: 116.66%,) 1,9-heptadecadiene-4,6-diyn-3-ol (HDD: 116.67%), β-damastrone (BDS: 116.67), and megastigmatrienone A (MSTA: 116.67%) was increased. A metagenomics analysis of the microbial community in the fermented RTLC (FRTLC) was performed to elucidate the mechanism by which NAECs were produced. As a result, 24 groups of functional genes were identified, and among them, five families of carbohydrate-active enzymes, (i) glycoside hydrolase (GH), (ii) glycosyltransferase (GT), (iii) polysaccharide lyase (PL), (iv) carbohydrate esterase (CE), and (v) auxiliary active enzyme (AA), were found to be positively correlated with the production of NAECs. However, among the GHs, the GHs annotated from the H8 strain chromosome displayed the highest relative abundance and a positive correlation with the production of NAECs. Specifically, the GH13-14, GH13-20, GH13-38, GH13-25, GH13-10, GH42, and GH28 genes of the H8 strain were relatively more abundant and were key contributors to the production of NAECs. The correlation analyses revealed that the H8 strain plays a leading role among all the microorganisms in FRTLC in the production of NAECs. Our findings support the application of Klebsiella variicola in NAEC production and a reduction in nicotine content in tobacco products.

Ondansetron attenuates cisplatin-induced behavioral and cognitive impairment through downregulation of NOD-like receptor inflammasome pathway

Cisplatin is an effective and commonly used chemotherapeutic drug; however, its use is accompanied by several adverse effects, including chemobrain. Ondansetron is a 5-HT3 antagonist, commonly used in prophylactic against chemotherapy-induced nausea and vomiting. Moreover, it has been identified as a novel neuroprotective agent in different animal models. However, its protective role against chemotherapy-induced chemobrain has not been investigated. The current study was the first study that explored the potential neuroprotective effect of ondansetron against cisplatin-induced chemobrain in rats. Cisplatin (5 mg/Kg) was injected intraperitoneally, once weekly, for 4 weeks with the daily administration of ondansetron (0.5 and 1 mg/Kg). Compared to the cisplatin-treated group, ondansetron administration showed a significant decrease in the latency time and a significant increase in ambulation, rearing, and grooming frequency in the open field test (OFT). Moreover, a significant improvement in the latency time in the rotarod and passive avoidance tests, following ondansetron administration. In addition, ondansetron treatment increased the percentage of alternation in the Y-maze test. Also, ondansetron showed a remarkable enhancement in the biochemical parameters in the hippocampus. It increased the acetylcholine (Ach) level and decreased the level of the acetylcholine esterase enzyme (AchE). Ondansetron significantly decreased interleukin-1β (Il-1β), tumor necrosis factor-alpha (TNF-α), toll-like receptor-4 (TLR-4), NOD-like receptor-3 (NLRP3) inflammasome as well as caspase-1 and caspase-3 levels. Furthermore, ondansetron significantly decreased the levels of copper transporter-1(CTR1) expression in the hippocampus. Collectively, these findings suggest that ondansetron may exhibit a neuroprotective and therapeutic activity against cisplatin-induced chemobrain.

Organik Tarım Yöntemleri ile Yetiştirilmiş Lycium barbarum İnfüzyonunun Standardizasyonu ve Antioksidan ve Enzim İnhibitör Etkileri

The cultivation of medicinal and aromatic plants with conventional and organic farming techniques in order to protect biodiversity due to depleted natural resources is becoming increasingly common. The expense of organic farming techniques necessitates more careful selection of the plants to be grown. Evaluation of the bioactivity and phytochemical contents of these plants is important for the pharmaceutical and food industry. In this study, the antioxidant, antidiabetic, anticholesterolemic and antiobesity activities of the extracts obtained from the fruit, root and leaves of Lycium barbarum grown with organic farming techniques using infusion and decoction techniques were evaluated in vitro. The phytochemical contents of the extracts were investigated by spectroscopic and chromatographic techniques. In the study in which five different antioxidant activity methods were used, L. barbarum root decoction showed a strong antioxidant effect in almost all methods. While none of the extracts exerted an inhibitory effect on the α-glucosidase enzyme, the leaf infusion of the plant at 2 mg mL-1 concentration caused strong inhibitions especially on pancreatic lipase (62.16±3.33%) and pancreatic cholesterol esterase (93.98±0.54%) enzymes compared to the reference compounds. L. barbarum leaf infusion was standardized by RP-HPLC technique on the basis of chlorogenic acid (1.339±0.056 g 100g-1 dry extract) and quercetin-3-O-glucoside (1.801±0.042 g 100g-1 dry extract) as markers. The findings displayed that leaf infusions of L. barbarum grown with organic farming techniques could be the source of natural product development studies for hypercholesterolemia and obesity control, and the extract could be standardized using chlorogenic acid and quercetin-3-O-glucoside as markers.

The Potential of Bacillus altitudinis B538 and Alcaligenes faecalis B947 in PET and PCL Plastic Degradation

Polyethylene terephthalate (PET) plastic is the most widely used type of plastic that produces waste and causes various environmental and health problems. The treatment of PET plastic waste with chemically and mechanically recycling approaches still has shortcomings, so biological processing using microorganisms or enzymes has new potential. Two bacterial isolates from the Indonesian Culture Collection of National Research and Innovation Agency (InaCC, BRIN), namely isolate InaCC B538 and InaCC B947, were further observed for their potential in PET plastic degradation. Firstly, both isolates were determined by the molecular marker 16S rDNA. The potential of both isolates was measured with following method: 10 days of degradation using PET and PCL substrates, esterase enzyme activity assay, and observation of the PET plastic surface using Scanning Electron Microscope (SEM). Species identification was performed using DNA sequencing of 16S rDNA. InaCC B538 and InaCC B947 were closely related to Bacillus altitudinis TBMAX41 and Alcaligenes faecalis AN-13, respectively. InaCC B947 isolate has a better potential in degrading PET plastic and PCL with a degradation percentage of 0.32% for PET plastic and 3.22% for PCL film for 10 days, respectively, and esterase activity of 0.06 U/ml; while InaCC B538 did not cause weight loss of PET and 2.49% for PCL, respectively, with esterase activity of 0.04 U/ml. The degradation of PET plastic by the isolates InaCC B947 was able to cause damage to the plastic surface leading to the degradation of PET plastic.

Inhibition of carbonic anhydrase and cholinesterase enzymes by acetone extract of Bryoria capillaris (Ach.) Brodo & D.Hawksw.

In traditional medicine, people commonly consume Bryoria capillaris (BC) as flour and tea, particularly in Northeast Anatolia, where it is one of the most prevalent lichen species. This study aimed to obtain an acetone extract of BC and investigate its inhibitory effects on carbonic anhydrase (CA) I, CA II, acetylcholine esterase (AChE), and butyrylcholine esterase (BChE) enzymes. We determined IC50 values of BC for each enzyme to measure the level of inhibition. The IC50 values for CA I and CA II were 8.77 μg/mL and 7.56 μg/mL, respectively. Acetazolamide, a specific CA I and II inhibitor, had IC50 values of 1.65 and 0.016 μg/mL, respectively. The IC50 values of BC for AChE and BChE were 7.96 and 8.58 μg/mL, respectively. Galantamine had IC50 values of 4.68 and 16.07 μg/mL for AChE and BChE, respectively. These results indicate that BC extract has a high potential to provide new drug candidates for all the tested enzymes, particularly for BChE.

How does warmer sea water change the sensitivity of a Mediterranean thermophilic coral after immune-stimulation?

Anthropogenic climate change is warming sea water worldwide, pushing the limits of tolerance for marine organisms and driving a decline in biodiversity. The risk of thermal anomalies has increased particularly in the Mediterranean region over the last 30 yrs, where intense warming has been identified as one of the main stressors in coastal regions. To determine the influence of warmer conditions on the immunity of an endemic Mediterranean coral species, different immune activity parameters were compared in response to elevated temperature (~ 28 °C) and the presence of a pathogen-associated molecular pattern—Escherichia coli lipopolysaccharide (LPS)—as an elicitor of the innate immune response of Astroides calycularis. Immune parameters, which included phenoloxidase-like, glutathione peroxidase, lysozyme-like, alkaline phosphatase, and esterase enzyme activity, were measured over time after LPS balneation (0-, 12-, 48-, and 120 h time point). All five enzymes demonstrated constant values under environmental conditions (~ 23 °C), indicating a constituent activity. LPS at environmental temperature induced significant upregulation immediately after exposure (0 h-time point), demonstrating an immune response to the pathogen elicitor. Under warmer conditions (~ 28 °C), constituent values increased over time, indicating a shift in the immune strategy to maintain homeostasis. However, warmer sea water, within the summer range experienced by this coral species, impaired the immune response to LPS, delaying it over time. These changes in immune strategy indicate that temperature affects coral immunity and, in thermophilic A. calycularis, results in an energy trade-off that could maintain its health-state through suboptimal conditions during multiple perturbations, such as summertime diseases.

The roles of the biochemical and molecular changes in resistance of Tetranychus urticae populations selected with spiromesifen+abamectin mixture </p >

The physiological changes in Tetranychus urticae selected with spiromesifen+abamectin (S+A) mixture formulation were demonstrated by biochemical and molecular methods. The susceptible (GSS) population of T. urticae, was selected with S+A and made resistant with increasing doses of the mixture formulation. The resistant population was divided into two, and selection pressure was terminated in one population which is named IR (Interrupt resistant). In the other population, the selection with S+A was continued and the population named IR2. Activities of some detoxification enzymes (esterase, glutathione-S-transferase (GST) and cytochrome P450) were investigated in the GSS and IR populations. The activity of esterase, GST and P450 enzymes were increased by 1.77, 2.57 and 2.58-fold, respectively, in the IR population compared to the GSS population. Also, investigation of synergistic effects with esterase inhibitor (TTP), GST inhibitor (DEM) and P450 inhibitor (PBO) in this population revealed that all three synergists showed significant synergistic effects in IR population. In molecular studies, when the population was screened for the presence of two previously identified glutamate channel mutations (G314D and G326E) by qPCR with TaqMan probes no mutations could be detected in glutamate channels. and the CTD domain of acetyl coenzyme-A carboxylase (ACCase). Furthermore, possible genetic mutations in the biotin carboxylase domain (BCD) and carboxyl transferase domain (CTD) of the ACCase target sites were determined by sequencing. Although a single amino acid mutation G37D in the BCD of the ACCase gene of the IR and IR2 populations was detected, its association with spiromesifen resistance was not confirmed. The results indicated that increased detoxification and possible target site mutation may be responsible for the S+A resistance in the IR and IR2 populations.

In-Vitro Acetylcholine Esterase Enzyme Inhibition Potential of Siddha Formulation Vilvaver Chooranam: A Neuroprotective Assay

Background and Aim: Alzheimer's disease (AD) is a progressive neurodegenerative condition evidenced by significant cognitive dysfunction. The state of cognitive impairment is made worse by increased levels of the enzyme acetylcholinesterase (AChE), which is crucial in the hydrolysis of the neurotransmitter acetylcholine (ACh). Siddha therapy gaining higher momentum in recent days due to its global acceptance considering its broad spectral safety and therapeutic window. Siddha originated from the southern geographic landscape of Asia now spreading its wings across the bounders in managing dreadful diseases like AD. The main objective of the present study is to evaluate AChE inhibition of the Siddha formulation Vilvaver Chooranam (VVC). Materials & Methods: In-Vitro Acetylcholine esterase enzyme inhibition Potential of Siddha formulation Vilvaver Chooranam by Ellman’s method. Results:Results obtained from the study clearly demonstrate that the formulation VVC has shown promising acetylcholinesterase at stipulated concentration dose-dependently. Maximum percentage inhibition of about 54.53 ± 3.475 % was observed at 500μg/ml with the IC50 value of 411.9 ± 30.6 µg/ml when compared to that of the Physostigmine, a known AChE Inhibitor with a maximum inhibition 93.44 ± 4.434 % at the concentration of 40μg/ml with the IC50 value of 10.38± 5.29 µg/ml. Conclusion: These findings demonstrate the remarkable potential of these extracts as valuable sources of antioxidants with interesting acetylcholinesterase inhibitory activity.

Ceria nanoparticles immobilized with self-assembling peptide for biocatalytic applications.

Peptide-based artificial enzymes exhibit structure and catalytic mechanisms comparable to natural enzymes but they suffer from limited reusability due to their existence in homogenous solutions. Immobilization of self-assembling peptides on the surface of nanoparticles can be used to overcome limitations associated with artificial enzymes. A high, local density of peptides can be obtained on nanoparticles to exert cooperative or synergistic effects, resulting in an accelerated rate of reaction, distinct catalytic properties, and excellent biocompatibility. In this work, we have immobilized a branched, self-assembled, and nanofibrous catalytic peptide, (C12-SHD)2KK(Alloc)-NH2, onto thiolated ceria nanoparticles to generate a heterogeneous catalyst with an enhanced number of catalytic sites. This artificial enzyme mimics the activities of esterase, phosphatase, and haloperoxidase enzymes and the catalytic efficiency remains nearly unaltered when reused. The enzyme-mimicking property is investigated for pesticide detection, bone regeneration, and antibiofouling applications. Overall, this work presents a facile approach to develop a multifunctional heterogeneous biocatalyst that addresses the challenges associated with unstable peptide-based homogeneous catalysts and, thus, shows a strong potential for industrial applications.

Assessment of Kaistella jeonii esterase conformational dynamics in response to poly(ethylene terephthalate) binding

The pervasive presence of plastic in the environment has reached a concerning scale, being identified in many ecosystems. Bioremediation is the cheapest and most eco-friendly alternative to remove this polymer from affected areas. Recent work described that a novel cold-active esterase enzyme extracted from the bacteria Kaistella jeonii could promiscuously degrade PET. Compared to the well-known PETase from Ideonella sakaiensis, this novel esterase presents a low sequence identity yet has a remarkably similar folding. However, enzymatic assays demonstrated a lower catalytic efficiency. In this work, we employed a strict computational approach to investigate the binding mechanism between the esterase and PET. Understanding the underlying mechanism of binding can shed light on the evolutive mechanism of how enzymes have been evolving to degrade these artificial molecules and help develop rational engineering approaches to improve PETase-like enzymes. Our results indicate that this esterase misses a disulfide bridge, keeping the catalytic residues closer and possibly influencing its catalytic efficiency. Moreover, we describe the structural response to the interaction between enzyme and PET, indicating local and global effects. Our results aid in deepening the knowledge behind the mechanism of biological catalysis of PET degradation and as a base for the engineering of novel PETases.

Combination effect of azadirachtin and chlorantraniliprole with three synergists against a serious invasive agricultural pest Spodoptera frugiperda (Lepidoptera: Noctuidae)

The fall armyworm, Spodoptera frugiperda, is a newly invading polyphagous pest that affects crops such as maize, sorghum, and corn in India. The pest has developed resistance to various chemical insecticides, including Bt toxins and insect growth regulators. Therefore, there is an urgent need for alternative methods to manage this pest. The present study aimed to investigate the effect of three synergists in combination with pesticides. The results showed a high resistance ratio to chlorantraniliprole (RR-52.7) and low resistance to azadirachtin (RR-3.8) in the HSR field population compared to the susceptible population (Sus). In vitro enzyme inhibition experiments with PBO and TPP synergists revealed that resistance to chlorantraniliprole was mediated by esterase, GST and MFO. However less resistance to azadirachtin was mediated by esterase enzyme. The field population exhibited a 2.0-fold higher esterase activity (20 μmol/min/mg protein) in response to chlorantraniliprole, followed by MFO activity (30–32 μmol/min/mg protein). Gene expression analysis revealed four genes (CYP321A7, CYP321B1, CYP4C71, and CYP4G74) were differentially expressed in the HSR population (4.0–6.0-fold) in chlorantraniliprole treatment and no expressions were seen in azadirachtin treatment. Overall the study concludes that, possible mechanism of chlorantraniliprole resistance in S. frugiperda mediated by P450s, esterases and GST and less resistance to azadirachtin by esterase suggesting that combination of synergists with azadirachtin could be useful for management of Spodoptera frugiperda.

Trachyspermum ammi Bioactives Promote Neuroprotection by Inhibiting Acetylcholinesterase, Aβ-Oligomerization/Fibrilization, and Mitigating Oxidative Stress In Vitro.

Neurodegenerative diseases (NDs) are a large category of progressive neurological disorders with diverse clinical and pathological characteristics. Among the NDs, Alzheimer's disease (AD) is the most widespread disease, which affects more than 400 million people globally. Oxidative stress is evident in the pathophysiology of nearly all NDs by affecting several pathways in neurodegeneration. No single drug can manage multi-faceted diseases like NDs. Therefore, an alternative therapeutic strategy is required, which can affect several pathophysiological pathways at a time. To achieve this aim, hexane and ethyl acetate extract from Trachyspermum ammi (Carom) were prepared, and GC/MS identified the bioactive compounds. For the cell-based assays, oxidative stress was induced in SH-SY5Y neuroblastoma cells using hydrogen peroxide to evaluate the neuroprotective potential of the Carom extracts/bioactives. The extracts/bioactives provided neuroprotection in the cells by modulating multiple pathways involved in neurodegeneration, such as alleviating oxidative stress and mitochondrial membrane potential. They were potent inhibitors of acetylcholine esterase enzymes and displayed competitive/mixed-type inhibition. Additionally, anti-Aβ1-42 fibrilization/oligomerization and anti-glycation activities were also analyzed. The multi-faceted neuroprotection shown via Carom/Carvacrol makes it a prospective contender in drug development for NDs.

Determining enantiomeric excess utilizing ratiometric measurements of a deuterium labeled malonate by 1H NMR spectroscopy

Enantiomeric excess quantification is important in the synthesis of many small molecules. Esterase enzymes such as porcine liver esterase are known for their ability to generate high enantioselectivity. Many methods have been developed in order to measure the enantiomeric excess of a chiral mixture. Herein we report a new method of direct quantification by 1H NMR spectroscopy of an enantiomeric mixture using ratiometric measurements of an isotope labelled probe. Our method has been demonstrated to be comparable to that of HPLC and yield quantitative results with ease.