P-nitrophenyl Phosphate Research Articles

Ratiometric fluorescence immunoassay of SARS-CoV-2 nucleocapsid protein via Si-FITC nanoprobe-based inner filter effect.

The global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has necessitated rapid, easy-to-use, and accurate diagnostic methods to monitor the virus infection. Herein, a ratiometric fluorescence enzyme-linked immunosorbent assay (ELISA) was developed using Si-fluorescein isothiocyanate nanoparticles (FITC NPs) for detecting SARS-CoV-2 nucleocapsid (N) protein. Si-FITC NPs were prepared by a one-pot hydrothermal method using 3-aminopropyl triethoxysilane (APTES)-FITC as the Si source. This method did not need post-modification and avoided the reduction in quantum yield and stability. The p-nitrophenyl (pNP) produced by the alkaline phosphatase (ALP)-mediated hydrolysis of p-nitrophenyl phosphate (pNPP) could quench Si fluorescence in Si-FITC NPs via the inner filter effect. In ELISA, an immunocomplex was formed by the recognition of capture antibody/N protein/reporter antibody. ALP-linked secondary antibody bound to the reporter antibody and induced pNPP hydrolysis to specifically quench Si fluorescence in Si-FITC NPs. The change in fluorescence intensity ratio could be used for detecting N protein, with a wide linearity range (0.01–10.0 and 50–300 ng/mL) and low detection limit (0.002 ng/mL). The concentration of spiked SARS-CoV-2 N protein could be determined accurately in human serum. Moreover, this proposed method can accurately distinguish coronavirus disease 2019 (COVID-19) and non-COVID-19 patient samples. Therefore, this simple, sensitive, and accurate method can be applied for the early diagnosis of SARS-CoV-2 virus infection.Electronic Supplementary MaterialSupplementary material (characterization of Si-FITC NPs (FTIR spectrum, XRD spectra, and synchronous fluorescence spectra); condition optimization of ALP response (fluorescence intensity ratio change); mechanism investigation of ALP response (fluorescence lifetime decay curves and UV—vis absorption spectra); detection of N protein using commercial ELISA Kit; analytical performance of assays for ALP detection or SARS-CoV-2 N protein detection; and determination results of SARS-CoV-2 N protein in human serum) is available in the online version of this article at 10.1007/s12274-022-4740-5.

Spatiotemporal distributions and relationships of phosphorus content, phosphomonoesterase activity, and bacterial phosphomonoesterase genes in sediments from a eutrophic brackish water lake in Chile

Phosphorus (P) cycling by microbial activity is highly relevant in the eutrophication of lakes. In this context, the contents of organic (Po) and inorganic (Pi) phosphorus, the activity of acid (ACP) and alkaline (ALP) phosphomonoesterase (Pase), and the abundances of bacterial Pase genes (phoD, phoC, and phoX) were studied in sediments from Budi Lake, a eutrophic coastal brackish water lake in Chile. Our results showed spatiotemporal variations in P fractions, Pase activities, and Pase gene abundances. In general, our results showed higher contents of Pi (110–144 mg kg−1), Po (512–576 mg kg−1), and total P (647–721 mg kg−1) in sediments from the more anthropogenized sampling sites in summer compared with those values of Pi (86–127 mg kg−1), Po (363–491 mg kg−1) and total P (449–618 mg kg−1) in less anthropogenized sampling sites in winter. In concordance, sediments showed higher Pase activities (μg nitrophenyl phosphate g−1 h−1) in sediments from the more anthropogenized sampling sites (9.7–22.7 for ACP and 5.9 to 9.6 for ALP) compared with those observed in less anthropogenized sampling sites in winter (4.2–12.9 for ACP and 0.3 to 6.7 for ALP). Higher abundances (gene copy g−1 sediment) of phoC (8.5–19 × 108), phoD (9.2–47 × 106), and phoX (8.5–26 × 106) genes were also found in sediments from the more anthropogenized sampling sites in summer compared with those values of phoC (0.1–1.1 × 108), phoD (1.4–2.4 × 106) and phoX (0.7–1.2 × 106) genes in the less anthropogenized sites in winter. Our results also showed a positive correlation between P contents, Pase activities, and abundances of bacterial Pase genes, independent of seasonality. The present study provided information on the microbial activity involved in P cycling in sediments of Budi Lake, which may be used in further research as indicators for the monitoring of eutrophication of lakes.

Artificial phosphatase upon premicellar nanoarchitectonics of lanthanum complexes with long-chained imidazole derivatives

Four novel long chain-containing tridentate imidazole derivatives (Ln, n = 1, 2, 3, 4) were synthesized for in situ formation of mononuclear lanthanum(III) complexes as artificial phosphodiesterases. These in-situ formed La(III) complexes (named LaLn) were used to catalyze the transesterification of 2-hydroxypropyl p-nitrophenyl phosphate (HPNP), a classic RNA model. Critical aggregation concentrations (CAC) were determined for the as-prepared tridentate imidazole derivatives as ligands and corresponding mixtures of equivalent ligand and La3+ ion with a mole rate of 1:1. It denotes that the introduction of La3+ ion increases the CAC values of imidazole derivatives by about 2 to 3 folds. Foaming test shows that the foam height is positively correlated with the length of hydrophobic chain. Transesterification of HPNP mediated by LaLn nanoarchitectonics indicates that the introducing of hydrophobic chain benefits rate enhancement, showing excess three orders of magnitude acceleration under physiological conditions (pH 7.0, 25 °C). Moreover, catalytic reactivities of these La(III) complexes increased along with the increase in chain length: LaL1 < LaL2 < LaL3 < LaL4, suggesting a positive correlation to hydrophobic chain length.

Antibodies for the Coat Protein of Cotton Leafroll Dwarf Virus Detect Commelina sp. as an Intermediary Host for Cotton Blue Disease.

The cotton blue disease, caused by the cotton leafroll dwarf virus (CLRDV), leads to dwarfism, leaf rolling, and production loss in susceptible cotton varieties. To develop an enzyme-linked immunosorbent assay (ELISA) test to detect the virus in cotton and weeds, peptides based on the coat protein were used to produce polyclonal (α-GQE, α-PRN, and α-INK) and monoclonal (α-GQE, α-PRN, and α-NKF) antibodies. All six were tested as capture antibodies, and polyclonal α-GQE and the monocle onal α-NKF were labeled with the enzyme alkaline phosphatase and used as detection antibodies for a double antibody sandwich (DAS) ELISA method, in which p-nitrophenyl phosphate was added and measured by absorbance at 405 nm. The DAS-ELISA sandwich was efficient in discriminating between healthy and diseased plant extracts. The ELISA methodology detected the virus in the weeds Commelina sp., which was confirmed by RT-PCR. The monoclonal antibodies may be used to develop other diagnostic procedures.

Organophosphate eradication by phytochemical cocktail stabilized biocompatible silver nanoparticles loaded polydopamine via peroxidase mimicking activity

• Phytochemical cocktail stabilized AgNP decorated on biopolymer polydopamine by single pot approach. • AgNP@PDA has shown peroxidase mimicking activity as a synergetic role of AgNP and PDA for TMB oxidation and •OH radical generation. • The enhanced degradation efficiency of AgNP@PDA for p -NPP via peroxidase mimicking activity than AgNP. • PDA enhanced antibacterial activity and economy of AgNP@PDA. • The improved cytocompatibility of AgNP by biocompatible PDA. Organophosphates are the nerve agent simulant structure and are classified as widely used insecticides. Their exposure turns lethal due to instant blockage of neural communication by inhibiting acetylcholinesterase enzyme. In the present study, a single pot technique was employed to produce silver nanoparticles (AgNP) using a phytochemical cocktail of gallic acid and quercetin as reducing and stabilizing agents, decorated on the biopolymer polydopamine (PDA). The AgNP@PDA exhibits peroxidase mimicking activity mediated degradation of p -nitrophenyl phosphate ( p -NPP) an organophosphate representative at pH 7. Peroxidase mimicking activity study revealed oxidation of TMB by reducing Ag + ion generated from AgNP upon H 2 O 2 exposure. However, the H 2 O 2 upon interaction with surface AgNP produces hydroxyl anion and subsequently •OH radicals where PDA serves as an ultimate electron sink. Compared to individual components, AgNP@PDA has shown maximum p -NPP degradation efficiency ( k (AgNP@PDA) = 3.91 × 10 -2 min. −1 , k (AgNP) = 0.24 × 10 -2 min. −1 , k (H 2 O 2 ) = 0.17 × 10 -2 min. −1 ). The kinetics of AgNP@PDA for p -NPP degradation has shown well-fitted Michaelis Menten behavior with K m = 0.016 mM and V max = 2.80 × 10 -5 which is ten-fold higher than AgNP. The degradation mechanism was proposed based on electrospray ionization mass spectroscopy which suggests the breaking of the phospho-ester bond. The extent of mineralization of organic skeleton was assessed by a significant decrease in total organic carbon (TOC). The presence of PDA has improved the antibacterial activity with AgNP and cytocompatibility of AgNP@PDA than AgNP.

USEFULNESS OF THERMO LABILE ALKALINE PHOSPHATASE AS A BIOMARKER IN DIAGNOSIS OF POST-MENOPAUSAL OSTEOPOROSIS

Background: Osteoporosis is characterized by demineralization of bones and it is a complication of women in post-menopausal life. Bone alkaline phosphatase is an isoenzyme of alkaline phosphatase which helps in the mineralization of bones and it is heat labile in nature. Its measurement facilitates the clinical diagnosis of Osteoporosis. Objectives: To assess the status of total alkaline phosphatase and heat-labile isoenzyme fraction (bone fraction) in serum of pre and post-menopausal women and to relate the findings to the clinical condition /final diagnosis to make out the correlation between the pre and postmenopausal women. Methodology:A total of 70 subjects, consisting of 35 pre-menopausal women (38.11 ± 4.3 years of age) and 35 post-menopausal women (54.40 ± 4.6 years) were constituted for the study. Their total alkaline phosphatase was measured directly and the heat stable alkaline phosphatase was measured after heating the serum at 56℃ for 10 minutes. Spectrophotometric P- Nitro-Phenyl Phosphate method was followed for the estimation. Heat labile alkaline phosphatase levels were obtained by subtracting the heat stable fraction from total Alkaline phosphatase. Result: The measured serum total alkaline phosphatase level was slightly increased in post menopause compared to premenopausal women but it was not statistically significant. The levels of heat-labile Alkaline phosphatase showed significant difference between pre and post-menopausal women by ***: p &lt; 0.01: ***: p &lt; 0.001 respectively. Conclusion: Heat labile alkaline phosphatase can be used as a biomarker to diagnose Osteoporosis in post-menopausal women.

Highly Efficient Mesoporous Carbonaceous CeO2 Catalyst for Dephosphorylation.

Phosphorus is fast becoming a critical element, as the global supply and demand are reaching unsustainable levels. Herein, the synthesis, characterization, and applicability of a novel biomass-derived mesoporous carbonaceous material decorated with CeO2 (CeO2-S400) as an efficient catalyst for the dephosphorylation of 4-nitrophenyl phosphate disodium salt hexahydrate are reported. The presence and distribution of CeO2 are evidenced by inductively coupled plasma mass spectrometry (ICP-MS) (118.7 mg/g), high-resolution transmission electron microscopy (HRTEM), and energy dispersive X-ray (EDX) mapping. The apparent rate constant for the efficient catalysis of 4-nitrophenyl phosphate disodium salt hexahydrate was 0.097 ± 0.01 for CeO2-ES and 0.15 ± 0.03 min–1 for CeO2-S400, which followed first-order kinetics. Rate constants normalized by the catalytic loading (km) were 80.84 and 15.00 g–1 min–1 for CeO2-ES and CeO2-S400, respectively, and the normalized rate constants with respect to surface area were 3.38 and 0.04 m–2 min–1 for CeO2-ES and CeO2-S400, respectively. This indicates that the presence of CeO2 nanoparticles has a catalytic effect on the dephosphorylation reaction.

Construction of hierarchically porous metal-organic frameworks via vapor atmosphere etching

Developing a versatile etching strategy for constructing hierarchically porous metal-organic frameworks (HP-MOFs) with anticipated mesopores and micropores remains a crucial scientific challenge in probing the enhanced performance and potential applications of MOF materials. Herein, a universal vapor etching method is implemented to controllably create HP-MOFs. Based on the principle that the concentration of vapor is lower than that of the solution, the etching rate and strength toward MOFs are greatly reduced, enabling us to obtain intermediate products during etching. Using this strategy, a series of desired HP-MOFs with varying metal nodes have been prepared. The resultant HP-MOFs integrate the merits of mesopores (mass transfer facilitation) and micropores (large internal surface area). For the degradation of the nerve agent, dimethyl 4-nitrophenyl phosphate, HP-UiO-66 exhibits better catalytic activity than pristine UiO-66.

Lanthanide ion exchange modulated via crystalline phase transition of a mixed-metal coordination polymer based on bis(4-nitrophenyl) phosphate

We previously reported that the CeL3 [L = bis(4-nitrophenyl) phosphate] coordination polymer (CP) exhibits exceptionally large differences in ion exchange selectivity toward neighboring ions in the lanthanide series (Ln3+). Herein we aimed to elucidate the mechanism of the unique ion-exchange behavior of CeL3 by focusing on the formation reaction of a mixed-metal CP (MM-CP) and the phase transition between two crystalline types, which occurs during the course of the ion-exchange reaction. The results of powder X-ray diffractometry of the de novo-synthesized MM-CPs indicated that the Ln3+-to-Ce3+ mixing limit, xlim, in the crystal is an important factor that determines the feasibility of the structural transition. Smaller Lu3+, Yb3+, and Tm3+ electrostatically interact with ligand molecules very strongly, which causes structural strain in MM-CP. Thus, the crystal-to-crystal structural transition tends to occur when the Ln3+ mixing ratio (x) is above xlim (∼0.2). The exchange of Ce3+ for Ln3+ (=Lu3+, Yb3+, and Tm3+) in the MM-CPs is further facilitated following structural transition because the crystalline structure formed after phase transition is known to prefer the heavy Ln3+ ions to Ce3+. In addition, the crystal lattice contracts during structural transition, and the intact CeL3 inside the particles is exposed to the solution phase, which may result in ion-exchange proceeding as a chain reaction. Hence, Ce3+-for-Ln3+ exchange is accelerated when x > xlim and disfavored when x < xlim. Consequently, large Ln3+-dependent differences in final reactivity are observed.

Enhanced peroxymonosulfate activation by (NH4)2Mo3S13 for organic pollutant removal: Crucial roles of adsorption and singlet oxygen

Though sulfide materials have attracted much attentions in sulfate radicals (SO4•–) based advanced oxidation processes, the catalytic performance and inherent mechanism of ammonium thiomolybdate ((NH4)2Mo3S13) activating peroxymonosulfate (PMS) are less studied. In this work, (NH4)2Mo3S13 materials were prepared by the hydrothermal method and applied as the PMS activator to degrade various organic pollutants. The (NH4)2Mo3S13/PMS system significantly decomposed tetracycline, oxytetracycline, methylene blue, and congo red. However, the degradation of carbamazepine, disodium p-nitrophenyl phosphate, norfloxacin, and sulfamethoxazole was relatively weaker. This selective catalytic performance was attributed to the adsorption affinities of (NH4)2Mo3S13 for organic pollutants. Besides, the exposed Mo(IV) and S on the surface of (NH4)2Mo3S13 were found to be the main active sites for activation of O2 and PMS. Among various active species, singlet oxygen was the crucial active species, while sulfate and hydroxyl radicals played limited roles for the removal of methylene blue in (NH4)2Mo3S13/PMS system. The findings of this work proved (NH4)2Mo3S13 materials are promising catalyst for organic pollutants removal in advanced oxidation processes.

Contributions of Cathepsin A and Carboxylesterase 1 to the hydrolysis of Tenofovir Alafenamide in the Human Liver, and the Effect of CES1 Genetic Variation on Tenofovir Alafenamide Hydrolysis

The prodrug tenofovir alafenamide (TAF) is a first‐line antiviral agent for the treatment of chronic hepatitis B infection. TAF activation involves multiple steps, and the first step is an ester hydrolysis reaction catalyzed by hydrolases. This study was to determine the contributions of carboxylesterase 1 (CES1) and cathepsin A (CatA) to TAF hydrolysis in the human liver. Our in vitroincubation studies showed that both CatA and CES1 catalyzed TAF hydrolysis in a pH‐dependent manner. At their physiological pH environment, the activity of CatA (pH 5.2) was 700‐1000‐fold higher than that of CES1 (pH 7.2). Given that the hepatic protein expression of CatA was approximately 200‐fold lower than that of CES1, the contribution of CatA to TAF hydrolysis in the human liver was estimated to be much greater than that of CES1, which is contrary to the previous perception that CES1 is the primary hepatic enzyme hydrolyzing TAF. The findings were further supported by a TAF incubation study with the CatA inhibitor telaprevir and the CES1 inhibitor bis‐(p‐nitrophenyl) phosphate. Moreover, an in vitrostudy revealed that the CES1 variant G143E (rs71647871) is a loss‐of‐function variant for CES1‐mediated TAF hydrolysis. In summary, our results suggest that CatA may play a more important role in the hepatic activation of TAF than CES1. Additionally, TAF activation in the liver could be affected by CES1 genetic variation, but the magnitude of impact appears to be limited due to the major contribution of CatA to hepatic TAF activation.

Assessing the microcystins concentration through optimized protein phosphatase inhibition assay in environmental samples

Protein phosphatase (PPase) inhibition assay (PPIA) is widely used to analyze the concentration of microcystins (MCs) because it is comparatively less expensive and faster than other assays. This study aimed to optimize the PPIA by determining a suitable reaction terminator and an optimal methanol concentration in the sample. The most suitable reaction time was 90 min, with the corresponding methanol concentration in the sample being 15% or less. When p-nitrophenyl phosphate (pNPP) was used as a substrate, copper chloride solution was suitably used as a reaction terminator, and when 4-methylumbelliferyl phosphate (MUP) was used, a glycine buffer not only increased the measurement sensitivity of the reaction product but also terminated the enzymatic reaction. When PPase 1 and MUP were used as an enzyme and a substrate, respectively, the limit of quantitation for MC-leucine/arginine (LR) was 0.02 µg/L, whereas it was 0.1 µg/L when pNPP was used as a substrate. The proposed method facilitated the measurement of MC-LR concentration without additional pretreatments, such as concentration or purification; therefore, this method was suitable and feasible for the continuous monitoring of MCs in drinking water.

Synthesis of TiO&lt;sub&gt;2&lt;/sub&gt; and ZrO&lt;sub&gt;2&lt;/sub&gt; nanomaterials for the degradation of nerve agent simulants

TiO2 and ZrO2 nanomaterials were successfully synthesized by sol gel method. Samples were characterized by X-ray difraction (XRD), Fourier-transform infrared spectroscopy (FTIR), N2 adsorption–desorption, Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS), SEM images and TEM images of TiO2 and ZrO2 samples showed the particle size of 10–20 nm. The results have revealed highly porous structure of ZrO2 and TiO2 nanomaterials with specific surface area of 116 m2g-1 and 125 m2g-1, respectively. The TiO2 and ZrO2 materials were used as the degradation of dimethyl 4-nitrophenyl phosphate (DMNP) chemical warfare agent emulator. The ZrO2 nanomaterial exhibited highly catalytic performance of DMNP degradation and the conversion reached to the value of 90.64 %, after 120 min of reaction.

Microwave-Assisted Synthesis of Porous Composites MOF-Textile for the Protection against Chemical and Nuclear Hazards.

Since the emergence of chemical, biological, radiological, and nuclear risks, significant efforts have been made to create efficient personal protection equipment. Recently, metal-organic framework (MOF) materials have emerged as new promising candidates for the capture and degradation of various threats, like chemical warfare agents (CWAs) or radioactive species. Herein, we report a new synthesis method of MOF-textile composites by microwave irradiation, with direct anchoring of MOFs on textiles. The resistance of the composite has been tested using normed abrasion measurements, and non-stable samples were optimized. The protection capacity of the MOF-textile composite has been tested against dimethyl 4-nitrophenyl phosphate, a common CWA simulant, showing short degradation half-life (30 min). Radiological/nuclear protection has also been tested through uranium uptake (up to 15 mg g-1 adsorbent) and the capture of Kr or Xe gas at 0.9 and 2.9 cm3/g, respectively.

Degradation of G-Type Nerve Agent Simulant with Phase-Inverted Spherical Polymeric-MOF Catalysts.

For the neutralization of chemical warfare agents (CWAs), the generation of an effective catalyst that can be handled safely and applied in personal protective equipment is required. Recently, zirconium-based metal-organic frameworks (Zr-MOFs: UiO-66 and UiO-67) have shown great promise in the degradation of CWAs, including nerve agents. Their catalytic activity is owed to the interplay of both Zr(IV) Lewis acids and Lewis basic groups in the MOF structure. The latter act as proximal bases that can interact with CWAs and improve the catalytic activity of Zr-MOFs. The powder form of MOFs, though, makes them impractical catalysts, as it is challenging to handle, regenerate, and reuse them. To address this challenge, we have synthesized three Zr-MOFs with Lewis basic amino and pyridine functionalities and shaped them in spherical polymeric beads using the phase inversion method. Using this method, we can generate beads with many polymer and MOF combinations (MOF@polymer). We controlled the MOF loading in these beads, and scanning electron microscopy images revealed that the MOF crystals are evenly distributed in the polymeric matrix, ensuring effective catalytic activity. We used these beads to degrade dimethyl p-nitrophenyl phosphate (DMNP), a simulant for the G-type nerve agent. Using 31P NMR, we showed that UiO-66-NH2@PES and UiO-67-(NH2)2@PES PES: poly(ether sulfone) beads destruct DMNP to dimethyl phosphate (DMP) with a half-life (t1/2) of 5.09 and 4.34 min, respectively. Beads made of hydrophobic polymers such as poly(vinylidene fluoride) (PVDF), polystyrene (PS), and Zr-MOFs with pyridine functionalities show that the quantitative hydrolysis of DMNP requires more time compared to that seen with the UiO-66-NH2@PES beads. Our work highlights the facile shaping of MOF powders into beads that can be easily regenerated with their catalytic activity to be maintained for at least three cycles of use.

Enrichment and analysis of circulating tumor cells by integrating multivalent membrane nano-interface and endogenous enzyme-signal amplification

For circulating tumor cells (CTCs)-based cancer diagnosis and monitoring, effective enrichment and specific analysis of CTCs present significant challenges. The biomembrane interfaces can enhance the high-affinity interactions between various receptors and ligands in life activities by mediating the rearrangement and positioning of membrane-bound components through its fluidity. Inspired by this, we have constructed a multivalent membrane nano-interface using aptamer-linked liposomes for the efficient capture of CTCs. Furthermore, the subsequent introduction of rolling circle amplification (RCA) reaction has increased the number of aptamers and extended them to the surrounding space to improve the affinity of the membrane nano-interface for CTCs. After CTCs are enriched, alkaline phosphatase overexpressed on the surface of tumor cells is used as endogenous enzyme-mediated signal amplification by catalyzing 4-nitrophenyl phosphate (pNPP) with color change, achieving the analysis of CTCs. Finally, the enrichment and visual analysis of human hepatocellular carcinoma (HepG2) with a detection limit of 10 cells/mL can be obtained by integrating the multivalent membrane nano-interface and endogenous enzyme signal amplification. The detection of the target in the serum proved this method has the potential for further clinical application and provides a potential method for studying the correlation between alkaline phosphatase dimer and cancer progression.

Synergistic enhancement of rat intestinal alkaline phosphatase activity by taurine and sodium butyrate protects against endotoxin-induced bowel inflammation.

The effect of sodium butyrate (SB) and taurine on rat intestinal alkaline phosphatase (RIA) and the effect of the interaction of taurine and/or SB with bacterial lipopolysaccharides on ALP activity were investigated. In vitro analysis of the activity of RIA was carried out using various concentrations of SB and/or taurine. Substrate concentration-dependent kinetic study was performed at 1-10mM of taurine and SB at 5.17mM of p-nitrophenyl phosphate (p-NPP). The in vivo effect of lipopolysaccharide (LPS) in the presence and absence of taurine and SB on the activity of RIA was also evaluated. LPS was administered to rats intraperitoneally and 20min after; this was followed by oral administration of SB and/or taurine. The hydrolysis of p-NPP by RIA was enhanced by taurine and SB at different concentrations. The in vivo kinetic study revealed that RIA activity was greater (588.23×10-3 μmol/min/ml) when taurine and SB were co-administered with bacterial LPS, yielding a low Km (0.12mM) value. This suggested an increased affinity for the substrate by the enzyme. The degree of activation was highest when SB and taurine were administered together with LPS. The study concluded that SB and taurine are activators of RIA and their positive synergistic interaction in the presence of bacterial LPS may further emphasize the role of both activators in attenuating bacterial LPS-mediated diseases. PRACTICAL APPLICATIONS: The development and progression of a myriad of diseases such as inflammatory bowel disease, atherosclerosis, sepsis, multiple sclerosis, and rheumatoid arthritis have been linked to bacterial endotoxin. Taurine is an amino acid derived from cysteine, while sodium butyrate is a short-chain fatty acid. Consumption of food and food supplement rich in taurine and sodium butyrate can help protect against endotoxemic injury and aid tissue repair in the small intestine, digestibility, growth, and overall health of animals.

Structural and functional identification of the uncharacterized metallo-β-lactamase superfamily protein TW9814 as a phosphodiesterase with unique metal coordination.

Metallo-β-lactamase (MBL) superfamily proteins have a common αβ/βα sandwich fold and perform a variety of functions through metal-mediated catalysis. However, because of the enormous scale of this superfamily, only a small percentage of the proteins belonging to the superfamily have been annotated structurally or functionally to date. Therefore, much remains unknown about the MBL superfamily proteins. Here, TW9814, a hypothetical MBL superfamily protein, was structurally and functionally investigated. Guided by the crystal structure of dimeric TW9814, it was demonstrated that TW9814 functions as a phosphodiesterase (PDE) in the presence of divalent metal ions such as manganese(II) or nickel(II). A docking model between TW9814 and the substrate bis(p-nitrophenyl)phosphate (bpNPP) showed the importance of the dimerization of TW9814 for its bpNPP-hydrolyzing activity and for the interaction between the enzyme and the substrate. TW9814 showed outstanding catalytic efficiency (kcat/Km) under alkaline conditions compared with other PDEs. The activity of TW9814 appears to be regulated through a disulfide bond, which is a feature that is not present in other MBL superfamily members. This study provides a platform for the functional characterization of other hypothetical proteins of the MBL or other superfamilies.

Attachment and Osteogenic Potential of Dental Pulp Stem Cells on Non-Thermal Plasma and UV Light Treated Titanium, Zirconia and Modified PEEK Surfaces.

Ultraviolet (UV) light and non-thermal plasma (NTP) treatment are chairside methods that can efficiently improve the biological aging of implant material surfaces caused by customary storage. However, the behaviors of stem cells on these treated surfaces of the implant are still unclear. This study aimed to investigate the effects of UV light and NTP treated surfaces of titanium, zirconia and modified polyetheretherketone (PEEK, BioHPP) on the attachment and osteogenic potential of human dental pulp stem cells (DPSCs) in vitro. Machined disks were treated using UV light and argon or oxygen NTP for 12 min each. Untreated disks were set as controls. DPSCs were cultured from the wisdom teeth of adults that gave informed consent. After 24 h of incubation, the attachment and viability of cells on surfaces were assessed. Cells were further osteogenically induced, alkaline phosphatase (ALP) activity was detected via a p-Nitrophenyl phosphate assay (day 14 and 21) and mineralization degree was measured using a Calcium Assay kit (day 21). UV light and NTP treated titanium, zirconia and BioHPP surfaces improved the early attachment and viability of DPSCs. ALP activity and mineralization degree of osteoinductive DPSCs were significantly increased on UV light and NTP treated surfaces of titanium, zirconia and also oxygen plasma treated Bio-HPP (p < 0.05). In conclusion, UV light and NTP treatments may improve the attachment of DPSCs on titanium, zirconia and BioHPP surfaces. Osteogenic differentiation of DPSCs can be enhanced on UV light and NTP treated surfaces of titanium and zirconia, as well as on oxygen plasma treated Bio-HPP.

Response Surface MethodologyBased Optimization, Partial Purification and Characterization of Alkaline Phosphatase Isolated from Pseudomonas asiatica Strain ZKB1 and its Application in Plant Growth Promotion.

The present study was defined to evaluate the effect of a combinational approach of applying phosphate-solubilizing bacteria and alkaline phosphatase for plant growth promotion as a novel strategy. An extracellular phosphatase producing novel Pseudomonas asiatica strain ZKB1 was isolated from ant hill soil. Alkaline phosphatase production was statistically optimized by Plackett-Burman and central composite designs with a yield of 42.45 U/ml and 5.88-fold enhancement. Alkaline phosphatase was purified by column chromatography (DEAE-Cellulose and Sephadex G-100) with 17.55-fold purification and specific activity of 87.77 U/mg. The molecular mass of purified phosphatase was ~ 45kDa. The optimum pH and temperature were 9.0 and 50°C, respectively, revealing alkali-thermostability. Phosphatase exhibited the highest specificity toward p-nitrophenyl phosphate disodium salt. Kinetic analysis revealed Km (0.434mM) and Vmax (264.44 U/mg). Alkaline phosphatase and Pseudomonas asiatica strain ZKB1 as phosphate-solubilizing bacteria were assessed for their ability to induce plant growth in pot experiments with Phaseolus mungo seeds. Seeds soaked in bacterial culture broth and irrigated with increased phosphatase concentration demonstrated better growth with plumule and radical length of 14.8 ± 0.2cm and 3.5 ± 0.4cm, respectively. Results were consistent with the combinational approach in terms of enhanced growth. The study suggests the application of alkaline phosphatases in agricultural management, crop improvements, and soil fertility enhancement.