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The study proposes an experimental approach to determining the rates of individual stages of a reaction catalyzed by bacterial luciferase, based on the tryptophan fluorescence of the protein and the stopped-flow technique. The relationship between the fluorescence intensity of tryptophan residues in luciferase and the presence of substrates and reaction products in the active site of the enzyme is substantiated. The non-steady-state kinetics of bioluminescence in the reaction of two bacterial luciferases with aliphatic aldehydes of different chain lengths, as well as the kinetics of enzyme fluorescence intensity during the reaction, were analyzed. The obtained results confirmed the relationship between the rate of the two kinetic stages of enzyme luminescence and the processes of flavin substrate binding and enzyme activity recovery after the catalytic act.
Insulin resistance and hepatic dysfunction are strongly associated with metabolic dysfunction-associated steatotic liver disease (MASLD). Non-pharmacological approaches, particularly dietary interventions, have demonstrated considerable potential for mitigating these conditions. In this network meta-analysis (NMA), we compared the relative efficacy of different dietary patterns on glycemic regulation and hepatic enzyme profiles. A comprehensive systematic search of PubMed, Scopus, Web of Science, Cochrane, and Google Scholar was conducted from inception to March 2025. The NMA was carried out based on both direct and indirect comparisons using random-effects models. Pooled analysis on 25 RCTs showed that DASH diet was more effective in reducing HOMA-IR (MD = -0.60; 95% CI: -1.14, -0.05; P-scores = 0.76; p = 0.03), AST (MD = -4.99; 95% CI: -8.76, -1.21; P-scores = 0.23; p = 0.009), compared to placebo. Low-Glycemic-Index Mediterranean Diet (LGIMD) approach led to a statistically significant but not clinically meaningful decrease in A1C levels compared to the placebo (MD = -0.01%; 95% CI: -0.01, -0.005; P-scores = 0.42; p < 0.001). The Mediterranean diet (MD) significantly reduced ALT levels compared with placebo (MD = -10.21; 95% CI: -20.22 to -0.20; p = 0.04; P-score = 0.70). The present NMA indicates that dietary interventions, including the Mediterranean diet, DASH, and certain low-glycemic approaches, are effective strategies for the management of MASLD. However, a LGIMD has shown mixed glycemic effects (reduction in A1c but increase in HOMA-IR), which warrant careful interpretation and further investigation.
Aromatic amino acids are essential precursors for numerous plant metabolites, with phenylalanine (Phe) forming the basis of the phenylpropanoid pathway. Here, we reveal a critical mechanism for Phe biosynthesis in maize, demonstrating that all seven arogenate dehydratases (ADTs) are specifically localized to plastoglobuli (PGs) in chloroplasts, and ADT2.2 shows high catalytic activity towards arogenate and prephenate. This discovery establishes PGs as a site for Phe synthesis. Genetic analysis confirms that only ADT2.2 is indispensable for plant and seed development, with its loss causing a severe Phe deficiency in seeds. This metabolic blockage directly reduced the tRNAPhe-GAA charging, thereby repressing protein translation. Crucially, we uncover that Phe starvation disproportionately affects the decoding efficiency of wobble-paired codons, increasing ribosome pausing. Our work provides biochemical and genetic evidence that PGs-localized ADT2.2 catalyzes Phe synthesis and reveals a link between amino acid availability and codon-specific translation dynamics.
Redox-controlled rotaxane formation can be employed as a novel strategy for cyclodextrin interconversion via a process of template-directed enzymatic synthesis, mechanical capture and release. Mechanical bonds are shown to protect cyclodextrins from hydolysis by α-amylase and cyclodextrin glucanotransferase, facilitating rotaxane isolation and enabling size-selective separation of cyclodextrins via reversible rotaxane formation.
To find for lead compounds, efficiently defeating diabetes mellitus, prompted us to the synthesis of a new library of adamantane‑appended 1,2,3-triazole hybrid conjugates (AT1-AT18). The current synthesis of adamantane-appended 1,2,3-triazoles was performed by using Cu(I)-catalyzed azide-alkyne cycloaddition reaction. The hybrids were structurally characterized via 1H, 13C NMR, FTIR, and mass spectrometry. The hybrids were evaluated for their inhibitory potential for α-glucosidase enzyme, along with in silico activity, i.e., molecular docking, molecular dynamics simulations, and ADME (absorption, distribution, metabolism, and excretion). Hybrid AT5 (IC50 5.5 ± 0.87 µM) showed maximum inhibition potential against α-glucosidase enzyme, which may be risen from the methyl substitution on phenyl ring. The results were compared with the reference, acarbose (IC50 13.5 ± 0.32 µM). The docking studies using PDB:3L4U revealed that the hybrid AT5 demonstrated a docking score -7.656, which was better than alkyne, i.e., -3.894. Ligand stability analysis explored by using molecular dynamics demonstrated the useful findings such as RMSD <2 Å, 0-2 H-bonds, for hybrid AT5, highlighting the stabilization contribution of triazole unit. The hybrid AT5 may be used as potential lead compound after necessary structural modifications. Two significant pharmacological units, i.e. adamantane and 1,2,3-triazole, were clubbed together to get a new series of alpha glucosidase inhibitors. Hybrid named AT5 showed highest potential against the enzyme. In silico studies carried out, using a computer software showed that the most potent hybrid AT5 binds to the active sites of enzyme. Drug-likeness (tendency of a drug to become orally active) properties of all the hybrids AT1-AT18 were checked.
Diseases such as Alzheimer's, Parkinson's, and depression result from neurotransmitter imbalances. In particular, for AD, it is critical to inhibit AChE to preserve the decline in acetylcholine levels and to block excessive MAO-B activity, which leads to nerve damage and cognitive impairment. As current scientific research has moved away from the "one drug for one target" approach toward a "multi-target" strategy, dual-acting inhibitors that simultaneously inhibit both AChE and MAO-B enzymes are considered the most promising new drug candidates for the treatment of Alzheimer's disease. In this study, we investigated the inhibition of AChE, BChE, MAO-A, and MAO-B in the pathophysiology of AD as a working group. Within the scope, 10 new compounds (5a-j) were synthesized, consisting of a phenolic ring, a secondary or tertiary amine tail, and a 1,2,4-triazole core. The cholinesterase and MAO inhibitory profiles of the compounds were investigated using both in vitro and in silico methods. Compound 5b exhibited dual inhibitory activity against AChE and MAO-B enzymes, with IC50 values of 0.136 ± 0.006 μM and 0.108 ± 0.005 μM, respectively. In accordance with 5b, it interacted with crucial amino acids of the hAChE and hMAO-B enzymes in the docking studies. These results suggest that 5b is a dual-target inhibitor of AChE and MAO-B and represents a promising therapeutic option for the treatment of Alzheimer's disease.
Following the down-selection of 14 Arabidopsis thaliana arogenate dehydratase (ADT) knockout and over-expression (OE) genotypes, the most highly contrasting quadruple knockout adt3/4/5/6 and ADT OE genotypes were subjected to proteomics, metabolomics, and scanning electron microscopy (SEM) analyses as needed, with results compared to Columbia wild-type (WT). The basal adt3/4/5/6 stem cross-sections, ∼70% lignin content reduced, exhibited buckled vessel cell walls and partially detached xylary fibers, in contrast to WT and ADT4m/5m OE genotypes that did not. Anatomical defects primarily resulted from guaiacyl lignin level reductions in vessels with concomitant increased stem syringyl:guaiacyl (S/G) ratios. Phenylpropanoid and various upstream shikimate-chorismate pathway enzyme abundances, as well as specific monolignol oxidases (laccases/peroxidases), generally increased in adt3/4/5/6 at different stem and rosette leaf growth/development stages, relative to WT. Opposite effects were largely observed with the ADT5m OE genotype. By contrast, flavonoid and glucosinolate pathway enzyme amounts varied. Such enzyme abundance increases were overall unproductive as adt3/4/5/6 was unable to restore WT, ADT4 OE, ADT5 OE, ADT5m OE, and ADT4m/5m OE secondary metabolite (lignin, phenylpropanoid, lignan, flavonoid, phenolic acid, and glucosinolate) levels. Conversely, ADT OE genotypes did not significantly increase programmed lignin levels or alter G/S compositions. In sum, proteomics analyses of adt3/4/5/6 and adt5 'perceived' that lignin and low molecular weight secondary metabolite amounts were not at 'programmed' levels as for WT and ADT OE genotypes but observed increases in relevant pathway protein abundances were futile. Notably though, proteomics analyses did not lead to predicting that lignin and associated biochemical pathways would have reduced metabolite levels, relative to WT and ADT OE genotypes. Genotype adt3/4/5/6, possibly the highest lignin level reduced genotype, did not utilize other phenolics to compensate. By contrast, the differential temporal and spatial deposition of cell wall oxidases again indicate the exquisite control over lignin deposition, and our lack of knowledge of precise lignin structure and assembly in subcellular regions of the lignified cell walls.
Characterization of previously reported Arabidopsis mutants with increased aluminum (Al) resistance (alr) resulting from greater release of Al-chelating malate identified three unique amino acid substitutions that each impacts PHOSPHOENOLPYRUVATE CARBOXYLASE 1, a key anaplerotic carbon fixation enzyme. Expression of mutant versions of AtPPC1 in an Arabidopsis ppc1 loss-of-function mutant increased Al resistance in association with upwards of threefold higher release of Al-chelating malate from roots. Analyses of enzyme kinetics and protein structure of the variants revealed that each amino acid position is critical to proper interplay between the allosteric regulator malate and the active site. Since these affect amino acid positions generally conserved amongst plant PPCs, they were individually introduced into maize PPCs including ZmPPC1, the isozyme responsible for the first step of C4 photosynthesis, and ZmPEP7, a key PPC in resupply of the TCA cycle via anaplerosis. This resulted in similar or greater improvements in enzyme activity and reduced regulation in vitro for both ZmPPC1 and ZmPEP7 along with increased PPC-dependent output in planta for a ZmPEP7 transgenic. Therefore, engineering these amino acid changes into plants in general could be useful for increasing carbon fixation by PPCs to turn excess CO2 into a resource for our growing population.
Alzheimer's disease (AD) is increasingly recognized as a metabolic disorder in which disruptions in cellular energy metabolism play a central role in its progression. The dysregulated metabolism of carbohydrates, proteins, fatty acids, and nucleic acids collectively impairs neuronal bioenergetics, leading to mitochondrial dysfunction and reduced ATP production. This impaired energy metabolism trigger a cascade of cellular stress responses, including endoplasmic reticulum (ER) stress, oxidative and inflammatory responses, and increased generation of amyloid-β (Aβ), thereby exacerbating neuronal vulnerability. A critical downstream consequence of bioenergetic failure is the altered epigenetic and post-translational regulatory enzymes, particularly the acetyltransferase EP300 and the NAD+-dependent deacetylases known as sirtuins. An imbalance in the activity of these enzymes promotes the abnormal tau acetylation, which disrupts tau-microtubule interactions and promotes tau aggregation, ultimately accelerating neurodegeneration. Emerging evidence suggests tau acetylation as a mechanistic link between metabolic dysfunction and hallmark pathological characteristics of AD, suggesting bioenergetic impairment directly regulate tau pathology. Thus, understanding the metabolic pathways that drive tau acetylation may offer new therapeutic targets aimed at restoring neuronal energy balance, re-establishing acetylation homeostasis, and potentially slowing the progression of AD.
RNA polymerase II (Pol II) must be assembled in the cytoplasm before it enters the nucleus, where it transcribes protein-coding genes. Although transcription by Pol II is intensively studied, how this central multi-subunit enzyme is made and the role of dedicated assembly factors remains unclear. Here, we report the integrative structural analysis of a native human Pol II from the cytoplasm captured near the end of biogenesis. The complex contains Gdown1 and three biogenesis factors - RPAP2 and the critical small GTPases GPN1 and GPN3. Cryo-EM analysis of the complex reveals how Gdown1 and RPAP2 associate with Pol II and prevent the premature association of transcription factors. Further biochemical and cryo-EM analysis reveals how RPAP2 tethers GPN1-GPN3 to the complex and how the assembly of the RPAP2-GPN1-GPN3 complex is controlled by GTP hydrolysis. The combined results uncover a network of interactions that chaperone cytoplasmic Pol II to prevent aberrant interactions, reveal a molecular switch regulating biogenesis factor association, and suggest a general mechanism for the action of GPN-loop GTPase family of enzymes.
Type 1 diabetes mellitus is characterized by insulin deficiency, hyperglycemia, and systemic metabolic and inflammatory disturbances that lead to multi-organ injury. Building on prior evidence that 6'-sialyllactose (SL), a sialylated human milk oligosaccharide, exerts anti-inflammatory and metabolic benefits, we investigated whether SL mitigates streptozotocin (STZ)-induced metabolic dysfunction and tissue injury in vivo. Male ICR mice were pretreated with SL (25 or 75 mg/kg) prior to STZ administration. STZ challenge markedly increased serum glucose levels, disrupted hepatic enzyme profiles, impaired protein metabolism, and induced liver apoptosis and inflammation. SL pretreatment significantly improved glucose homeostasis, normalized liver enzyme activities and serum protein indices, reduced hepatic caspase-3 activation, and suppressed pro-inflammatory cytokine expression in the liver and skeletal muscle. Mechanistically, SL restored AMPK-Akt-mTOR signaling in metabolic tissues. Collectively, these data demonstrate that SL confers systemic metabolic protection against STZ-induced diabetes, highlighting its potential as a therapeutic or preventive agent targeting inflammatory and metabolic pathways.
Duchenne muscular dystrophy (DMD) is a rare X-linked neuromuscular disorder characterised by heterogeneous early manifestations. This study summarised the clinical, pathological, and genetic characteristics of patients with DMD in northern China and identified useful indicators for diagnosis and disease assessment. Twenty-three DMD patients at the Second Hospital of Hebei Medical University between 2014 and 2022 were retrospectively reviewed. Clinical data, laboratory findings, electrocardiography, electromyography, muscle pathology, dystrophin immunohistochemistry, and DMD gene variants were analysed. Age at onset ranged from 0.5 to 7.5 years, mainly between 3.5 and 6.0 years. Bilateral lower-limb weakness and exercise intolerance were observed in 21 patients. All patients had elevated myocardial enzymes, decreased serum creatinine, elevated inorganic phosphate, and myogenic changes on electromyography; 22 had elevated transaminases and 17 had abnormal electrocardiograms. Muscle pathology showed connective tissue and fatty infiltration in all cases, with fibre atrophy. Dystrophin immunohistochemistry revealed complete loss of dystrophin-N/C/R in 21 patients and partial loss in two patients. Muscle strength was positively correlated with CK, CKMB, ALT, AST, LDH, and creatinine. Genetic testing identified 15 deletions, five duplications, and three small mutations, including a novel frameshift variant. Among 21 patients with parental testing, 10 mothers were carriers and 11 cases were considered de novo. DMD exhibited distinct clinicopathological and genetic patterns. Unexplained transaminase or myocardial enzyme elevation, decreased serum creatinine, and early motor abnormalities should prompt DMD genetic testing.
Benzyl alcohol, a simple aromatic alcohol found in more than half of seed plant families, plays important roles in plant-environmental interactions and serves as a precursor of benzyl benzoate, an intermediate in the phenylalanine-dependent biosynthesis of the phytohormone salicylic acid. Despite its importance, the enzyme responsible for benzyl alcohol formation in plants has remained unknown. Using a combination of classical biochemical, proteomic and genetic approaches, we demonstrated that two NADPH-dependent benzaldehyde reductases, differing by only three amino acids, are responsible for the formation of benzyl alcohol and its downstream derivatives, benzyl benzoate and methyl salicylate, in petunia flowers. Moreover, downregulation of benzaldehyde reductase expression substantially reduces salicylic acid levels in petunia stems upon pathogen infection. These findings provide direct evidence that benzaldehyde reductase is the last unidentified enzyme in salicylic acid biosynthesis via the benzyl benzoate intermediate. Moreover, the subcellular localization of benzaldehyde reductase homologs across flowering plants is species-specific, occurring either in peroxisomes or cytosol, suggesting that different species employ distinct compartmental organization for phenylalanine-dependent salicylic acid biosynthesis.
The anaerobic degradation pathway of phenanthrene starts with activation through carboxylation to 2-phenanthroic acid, followed by thioesterification to produce 2-phenanthroyl-CoA, which is then reduced to hexahydro-2-phenanthroyl-CoA by two ATP-independent type III aryl-CoA reductases (AprB and AprC) to overcome the resonance energy of the aromatic rings. In this study, we elucidated the reduction of hexahydro-2-phenanthroyl-CoA to octahydro-2-phenanthroyl-CoA and its subsequent reduction to the fully dearomatized diene decahydro-2-phenanthroyl-CoA. The two-electron reduction steps were catalyzed by the heterologously produced and purified hexahydro-2-phenanthroyl-CoA reductase (AprD) and octahydro-2-phenanthroyl-CoA reductase (AprE). AprD and AprE have specific activities of 12.7 and 6.3 nmol min-1 mg-1 and KM values of 15.1 and 63.9 nM, respectively. The ATP-independent and oxygen-sensitive reduction of hexahydro-2-phenanthroyl-CoA and octahydro-2-phenanthroyl-CoA catalyzed by AprD and AprE preferred dithionite-reduced methyl viologen as in vitro electron donor. AprD and AprE are monomeric enzymes with a molecular mass of ≈ 73 kDa and contain one FMN, one FAD, and one 4Fe-4S cluster, indicating that both reductases belong to the new type III aryl-CoA reductases of the old-yellow enzyme (OYE) family. The de-aromatization of 2-phenanthroyl-CoA aromatic rings through reduction was followed by water addition at the β-position of the cyclic diene, decahydro-2-phenanthroyl-CoA, producing β-hydroxydodecahydro-2-phenanthroyl-CoA. The hydration reaction was catalyzed by a homo-dimeric enoyl-CoA hydratase (ApcA) with a native molecular mass of ≈ 60 kDa and subunit molecular mass of ≈ 29 kDa. ApcA has a specific activity of 3.2 nmol min-1 mg-1 and a KM value of 31.5 nM at pH value of 7.5. The catalytic activity of ApcA was oxygen-insensitive and the reaction did not need any cofactor or metal ion. These findings reveal a novel strategy in the anaerobic degradation of aromatic hydrocarbons where only ATP-independent type III aryl-CoA reductases are involved in breaking the aromaticity of the ring system before the metabolites enter subsequent beta-oxidation reactions.
The widespread use of agricultural films has resulted in the pervasive accumulation of microplastics (MPs) and phthalates (PAEs) in soil, posing significant ecological toxicity risks to soil organisms. In this study, we investigated the toxic responses of Eisenia fetida following single and combined exposure to polyethylene microplastics (PE-MPs) and dibutyl phthalate (DiBP), covering survival, growth inhibition, oxidative stress, stress-related gene transcription, and histopathology. At the early exposure phase, co-stimulation by PE-MPs and DiBP markedly inhibited core antioxidant enzymes including superoxide dismutase (SOD) and catalase (CAT), while triggering sharp compensatory elevation of glutathione S-transferase (GST) activity. Such antioxidant imbalance triggered early lipid peroxidation and cell membrane injury, evidenced by elevated malondialdehyde (MDA) concentrations. Although partial recovery of antioxidant enzyme activity was observed at day 28, obvious oxidative DNA damage was detected. This DNA injury disturbed genomic homeostasis, as reflected by significantly upregulated transcription of calreticulin (CRT) and heat shock protein 70 (Hsp70), alongside suppressed expression of translationally controlled tumor protein (TCTP). Two-way ANOVA verified prominent interactive effects between PE-MPs and DiBP at the gene transcription level, with synergistic and antagonistic effects alternating under different concentration combinations. At the tissue level, the combined exposure eventually induced severe pathological lesions in the epidermis, muscle layers and intestinal wall, accompanied by obvious body weight loss in earthworms. Collectively, these results provide mechanistic insights into the interactive toxic effects of coexisting PE-MPs and DiBP, and offer fundamental data to support ecological risk evaluation of mixed microplastic-plasticizer pollution in farmland soils.
This study examined the role of brassinosteroid (BR) application in mitigating chilling injury (CI) in 'Donghong' kiwifruit during cold storage. BR markedly alleviated CI symptoms, reduced lignification, electrolyte leakage, and malondialdehyde accumulation. It suppressed ROS buildup (O₂·- and H₂O₂) and enhanced antioxidant capacity through elevated activities and gene expression of SOD, CAT, and enzymes in the AsA-GSH cycle. BR also increased unsaturated fatty acid content, inhibited phospholipid degradation, and improved membrane integrity by modulating related enzyme activities and gene expression. Furthermore, BR maintained higher energy status, as indicated by increased ATP and ADP levels, energy charge, and enhanced activities of H+-ATPase, Ca2+-ATPase, CCO, and SDH, along with their up-regulated gene expression. These results demonstrate that BR enhances chilling tolerance by regulating ROS metabolism, membrane lipid stability, and energy metabolism.
Pyrethroid-piperonyl butoxide (PBO) nets enhance malaria vector control by counteracting metabolic resistance mechanisms in malaria vectors through the synergistic action of PBO. DuraNet® Plus is an alpha-cypermethrin and PBO incorporated net developed Shobikaa Impex Private Limited. This study assessed its entomological efficacy relative to a standard pyrethroid-only net (DuraNet®) and an established pyrethroid-PBO net (Olyset® Plus), in support of WHO prequalification. Experimental hut trials were conducted at three ecologically and entomologically distinct sites with pyrethroid-resistant vector populations: Covè, Benin (Anopheles gambiae s.l.), Mibellon, Cameroon (An. funestus), and M'bé, Côte d'Ivoire (An. gambiae s.l.). Each net type was tested unwashed and after 20 standardized washes. Primary outcomes included 24-h mosquito mortality and blood-feeding inhibition. DuraNet® Plus was evaluated for non-inferiority to Olyset® Plus and superiority over DuraNet® using combined washed and unwashed data, in line with WHO guidelines. WHO bioassays confirmed pyrethroid resistance and assessed the role of cytochrome P450 enzymes. Chemical analyses measured pyrethroid and PBO retention after washing. DuraNet® Plus induced higher mosquito mortality than Olyset® Plus across all sites (Benin: 29.5% vs. 14.9%, OR = 2.81, 95% CI 2.34-3.38, NIM = 0.468; Cameroon: 27.8% vs. 22.2%, OR = 1.81, 95% CI 1.32-2.49, NIM = 0.62; Côte d'Ivoire: 19.5 vs. 12.0%, OR = 2.28, 95% CI 1.85-2.80, NIM = 0.37), with all odds ratios exceeding the WHO-defined non-inferiority margins. DuraNet® Plus also met non-inferiority criteria for blood-feeding inhibition compared to Olyset® Plus (Benin: OR = 0.23, 95% CI 0.18-0.28, NIM = 1.345; Cameroon: OR = 0.66, 95% CI 0.50-0.87, NIM = 1.32; Côte d'Ivoire: OR = 0.58, 95% CI 0.48-0.69, NIM = 1.40). In addition, DuraNet® Plus was superior to DuraNet® in both mosquito mortality and blood-feeding inhibition across all study sites (p < 0.05). Susceptibility bioassays confirmed high frequencies of pyrethroid resistance across all three sites, with varying levels of P450 enzyme involvement. Chemical analysis showed higher retention of alpha-cypermethrin and PBO in DuraNet® Plus after 20 washes compared with the permethrin and PBO content in Olyset® Plus. DuraNet® Plus showed strong entomological efficacy and wash durability against pyrethroid-resistant malaria vectors across varied settings in West and Central Africa. It met WHO non-inferiority criteria compared to Olyset® Plus and was superior to a pyrethroid-only ITN, supporting its inclusion among WHO-prequalified products. These findings underscore its potential role in vector control strategies in areas affected by metabolic pyrethroid resistance.
24S-hydroxycholesterol (24SOH-Chol) is a bioactive cholesterol metabolite formed in the brain. This endogenous activator of the cholesterol sensor, liver X receptor (LXR) is abundantly found as a sulfate-glucuronide diconjugate in the human plasma. The present study characterizes the human sulfonating (SULT) and glucuronidating (UGT) enzymes; and evaluates how these enzymes impact its ability to bind to and activate LXR. In vitro enzymatic assays identified the human SULT2A1 and UGT1A4 as the major isoforms for hepatic 24SOH-Chol sulfonation and glucuronidation, respectively. Additional assays demonstrated that 24SOH-Chol-3Sulfate,24Glucuronide formation requires the successive involvement of UGT1A4 and SULT2A1. TR-FRET and transient transfection experiments revealed that glucuronidation, but not sulfonation, inactivates 24SOH-Chol. Exposure of human liver cells and humanized UGT1 mice to LXR ligands identified UGT1A4, but not SULT2A1, as a positively regulated LXR target gene, while chromatin immunoprecipitation assays, luciferase reporter and siRNA knock down assays demonstrated the ability of LXR to bind to and activate the human UGT1A4 gene promoter. The present study establishes the complementary roles played by SULT2A1 and UGT1A4 in 24SOH-Chol conjugation. We also identify glucuronidation as a mechanism allowing this cholesterol derivative to self-stimulate its own inactivation.
Atherosclerosis is a chronic vascular disease driven in part by vascular smooth muscle cell (VSMC) phenotypic switching, migration, and excessive proliferation. In our previous work, Apelin-13 was shown to promote aerobic glycolysis and thereby stimulate VSMC proliferation. Here, we developed a novel 1,12-cyclic Apelin-12 peptide (c-Apelin-12) by cyclizing the N- and C-termini of Apelin-12 through an amide bond. We found that c-Apelin-12 effectively attenuated Apelin-13-induced VSMC proliferation, reduced mitochondrial injury, and suppressed aerobic glycolysis. In vivo, c-Apelin-12 treatment significantly decreased atherosclerotic plaque formation and reduced the expression of proliferation-associated markers and key glycolytic enzymes. These findings indicated that c-Apelin-12 mitigated Apelin-13-induced VSMC proliferation and atherosclerotic progression by alleviating aerobic glycolysis. c-Apelin-12 may therefore represent a promising therapeutic candidate for atherosclerosis.
Human herpesvirus (HHV) replication depends on the HHV protease (HHV Pr), an enzyme essential for capsid maturation. Because HHV Pr must transition from an inactive monomer to an active dimer, disrupting dimerization is a promising antiviral strategy. We isolate Fab5, a conformationally selective antibody from a naïve Fab-phage library that recognizes monomeric human cytomegalovirus protease (HCMV) Pr. A 2.6 Å cryo-EM structure reveals Fab5 binds a "latch loop" distal to the active site and dimer interface that secures the C-terminal tail in dimers. Structure-guided mutagenesis in both HCMV Pr and Kaposi's Sarcoma-associated herpesvirus (KSHV) Pr confirms the functional importance of a 3-residue motif present in β- and γ-HHV Pr latch loops, validating the mechanistic role of the latch loop in dimerization and activity. Because the latch loop is structurally conserved in all HHV Prs, the cryptic sites they form present an avenue for allosteric inhibitor development.