Differential expression of neuropeptide F in the digestive organs of female freshwater prawn, Macrobrachium rosenbergii, during the ovarian cycle.

Neuropeptide F is a key hormone that controls feeding in invertebrates, including decapod crustaceans. We investigated the differential expression of Macrobrachium rosenbergii neuropeptide F (MrNPF) in the digestive organs of female prawns, M. rosenbergii, during the ovarian cycle.

A high catalytic efficiency and chemotolerant formate dehydrogenase from Bacillus simplex.

NAD -dependent formate dehydrogenase (FDH) catalyzes the conversion of formate and NAD to produce carbon dioxide and NADH. The reaction is biotechnologically important because FDH is widely used for NADH regeneration in various enzymatic syntheses. However, major drawbacks of this versatile enzyme in industrial applications are its low activity, requiring its utilization in large amounts to achieve optimal process conditions.

Structure and biochemical characterization of an extradiol 3,4-dihydroxyphenylacetate 2,3-dioxygenase from Acinetobacter baumannii.

3,4-Dihydroxyphenylacetate (DHPA) 2,3-dioxygenase (EC 1.13.11.

Bridging the Gap: Can COVID-19 Research Help Combat African Swine Fever?

African swine fever (ASF) is a highly contagious and economically devastating disease affecting domestic pigs and wild boar, caused by African swine fever virus (ASFV). Despite being harmless to humans, ASF poses significant challenges to the swine industry, due to sudden losses and trade restrictions. The ongoing COVID-19 pandemic has spurred an unparalleled global research effort, yielding remarkable advancements across scientific disciplines.

Mangiferin is a new potential antimalarial and anticancer drug for targeting serine hydroxymethyltransferase.

Mangiferin, a polyphenolic xanthone glycoside found in various botanical sources, including mango (Mangifera indica L.) leaves, can exhibit a variety of bioactivities. Although mangiferin has been reported to inhibit many targets, none of the studies have investigated the inhibition of serine hydroxymethyltransferase (SHMT), an attractive target for antimalarial and anticancer drugs.

Reaction mechanism and kinetics of the two-component flavoprotein dimethyl sulfone monooxygenase system: Using hydrogen peroxide for monooxygenation and substrate cleavage.

The dimethyl sulfone monooxygenase system is a two-component flavoprotein, catalyzing the monooxygenation of dimethyl sulfone (DMSO ) by oxidative cleavage producing methanesulfinate and formaldehyde. The reductase component (DMSR) is a flavoprotein with FMN as a cofactor, catalyzing flavin reduction using NADH. The monooxygenase (DMSMO) uses reduced flavin from the reductase and oxygen for substrate monooxygenation.

Biochemical and structural characterization of meningococcal methylenetetrahydrofolate reductase.

Methylenetetrahydrofolate reductase (MTHFR) is a key metabolic enzyme in colonization and virulence of Neisseria meningitidis, a causative agent of meningococcal diseases. Here, the biochemical and structural properties of MTHFR from a virulent strain of N. meningitidis serogroup B (NmMTHFR) were characterized.

High sensitivity and low-cost flavin luciferase (FLUX)-based reporter gene for mammalian cell expression.

Luciferase-based gene reporters generating bioluminescence signals are important tools for biomedical research. Amongst the luciferases, flavin-dependent enzymes use the most economical chemicals. However, their applications in mammalian cells are limited due to their low signals compared to other systems.

Synthetic microbes and biocatalyst designs in Thailand.

Furthering the development of the field of synthetic biology in Thailand is included in the Thai government's Bio-Circular-Green (BCG) economic policy. The BCG model has increased collaborations between government, academia and private sectors with the specific aim of increasing the value of bioindustries sustainable approaches. This article provides a critical review of current academic research related to synthetic biology conducted in Thailand during the last decade including genetic manipulation, metabolic engineering, cofactor enhancement to produce valuable chemicals, and analysis of synthetic cells using systems biology.

The presence and distribution of gamma-aminobutyric acid and dopamine during the developmental stages of the sea cucumber, Holothuria scabra, with emphasis on settlement organs.

In the sea cucumber, Holothuria scabra, the competent larvae require main settlement organs (SOs), including the ciliary bands (CiBs), tentacles (Ts), podia (PDs), and cues from neurotransmitters, including gamma-aminobutyric acid (GABA) and dopamine (DA), for successful settlement. In the present study, we investigated the spatial distribution of GABA and DA in the developmental stages of H. scabra, with special emphasis on SOs by detecting immunoreactivity (-ir) against these two neurotransmitters.

A Multiplexed Cas13-Based Assay with Point-of-Care Attributes for Simultaneous COVID-19 Diagnosis and Variant Surveillance.

Point-of-care (POC) nucleic acid detection technologies are poised to aid gold-standard technologies in controlling the COVID-19 pandemic, yet shortcomings in the capability to perform critically needed complex detection-such as multiplexed detection for viral variant surveillance-may limit their widespread adoption. Herein, we developed a robust multiplexed clustered regularly interspaced short palindromic repeats (CRISPR)-based detection using LwaCas13a and PsmCas13b to simultaneously diagnose severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and pinpoint the causative SARS-CoV-2 variant of concern (VOC)-including globally dominant VOCs Delta (B.1.

Mechanistic roles of the neighbouring cysteine in enhancing nucleophilicity of catalytic residue in a two-cysteine succinic semialdehyde dehydrogenase.

Succinic semialdehyde dehydrogenase (SSADH) catalyses the conversion of succinic semialdehyde into succinic acid and two electrons are transferred to NAD(P) to yield NAD(P)H. Our previous work has already reported the catalytic role of Cys289 of two-cysteine SSADH from Acinetobacter baumannii (AbSSADH). However, the mechanistic role of the neighbouring conserved Cys291 and Glu255 remains unexplored.

Detection of cellular metabolites by redox enzymatic cascades.

Detection of cellular metabolites that are disease biomarkers is important for human healthcare monitoring and assessing prognosis and therapeutic response. Accurate and rapid detection of microbial metabolites and pathway intermediates is also crucial for the process optimization required for development of bioconversion methods using metabolically engineered cells. Various redox enzymes can generate electrons that can be employed in enzyme-based biosensors and in the detection of cellular metabolites.

Luciferin Synthesis and Pesticide Detection by Luminescence Enzymatic Cascades.

D-Luciferin (D-LH ), a substrate of firefly luciferase (Fluc), is important for a wide range of bioluminescence applications. This work reports a new and green method using enzymatic reactions (HELP, HadA Enzyme for Luciferin Preparation) to convert 19 phenolic derivatives to 8 D-LH analogues with ≈51 % yield. The method can synthesize the novel 5'-methyl-D-LH and 4',5'-dimethyl-D-LH , which have never been synthesized or found in nature.

QM/MM Molecular Modeling Reveals Mechanism Insights into Flavin Peroxide Formation in Bacterial Luciferase.

Bacterial luciferase (Lux) catalyzes oxidation of reduced flavin mononucleotide (FMN) and aldehyde to form oxidized FMN and carboxylic acid via molecular oxygen with concomitant light generation. The enzyme is useful for various detection applications in biomedical experiments. Upon reacting with oxygen, the reduced FMN generates C4a-peroxy-FMN (FMNH-C4a-OO) as a reactive intermediate, which is required for light generation.

Catalytic and structural insights into a stereospecific and thermostable Class II aldolase HpaI from Acinetobacter baumannii.

Aldolases catalyze the reversible reactions of aldol condensation and cleavage and have strong potential for the synthesis of chiral compounds, widely used in pharmaceuticals. Here, we investigated a new Class II metal aldolase from the p-hydroxyphenylacetate degradation pathway in Acinetobacter baumannii, 4-hydroxy-2-keto-heptane-1,7-dioate aldolase (AbHpaI), which has various properties suitable for biocatalysis, including stereoselectivity/stereospecificity, broad aldehyde utilization, thermostability, and solvent tolerance. Notably, the use of Zn by AbHpaI as a native cofactor is distinct from other enzymes in this class.

Comparative neuroanatomical distribution and expression levels of neuropeptide F in the central nervous system of the female freshwater prawn, Macrobrachium rosenbergii, during the ovarian cycle.

Neuropeptide F (NPF) plays critical roles in controlling the feeding and reproduction of prawns. In the present study, we investigated changes in the expression levels of Macrobrachium rosenbergii neuropeptide F (MrNPF), and its neuroanatomical distribution in eyestalk (ES), brain (BR), subesophageal ganglion (SEG), thoracic ganglia (TG), and abdominal ganglia (AG), during the ovarian cycle of female prawn. By qRT-PCR, the amount of MrNPF transcripts exhibited a gradual increase in the ES, BR, and combined SEG and TG from stages I and II, to reach a maximum level at stage III, and slightly declined at stage IV, respectively.

Use of Bacterial Luciferase as a Reporter Gene in Eukaryotic Systems.

Reporter gene assays are powerful tools for monitoring dynamic molecular changes and for evaluating the responses that occur at the genetic elements within cells in response to exogenous molecules. In general, various protein systems can be used as reporter genes, including luciferases. Here, the present protocol introduces a unique reporter gene system for monitoring molecular events in cells using bacterial luciferase (lux), which can generate blue-green light suitable for gene reporter applications with the highest cost performance.

Protonation status and control mechanism of flavin-oxygen intermediates in the reaction of bacterial luciferase.

Bacterial luciferase catalyzes a bioluminescent reaction by oxidizing long-chain aldehydes to acids using reduced FMN and oxygen as co-substrates. Although a flavin C4a-peroxide anion is postulated to be the intermediate reacting with aldehyde prior to light liberation, no clear identification of the protonation status of this intermediate has been reported. Here, transient kinetics, pH variation, and site-directed mutagenesis were employed to probe the protonation state of the flavin C4a-hydroperoxide in bacterial luciferase.

Bacterial luciferase: Molecular mechanisms and applications.

Bacterial luciferase is a flavin-dependent monooxygenase which is remarkable for its distinctive feature in transforming chemical energy to photons of visible light. The bacterial luciferase catalyzes bioluminescent reaction using reduced flavin mononucleotide, long-chain aldehyde and oxygen to yield oxidized flavin, corresponding acid, water and light at λ around 490nm. The enzyme comprises of two non-identical α and β subunits, where α subunit is a catalytic center and β subunit is crucially required for maintaining catalytic function of the α subunit.

Clinical validation of a Cas13-based assay for the detection of SARS-CoV-2 RNA.

Nucleic acid detection by isothermal amplification and the collateral cleavage of reporter molecules by CRISPR-associated enzymes is a promising alternative to quantitative PCR. Here, we report the clinical validation of the specific high-sensitivity enzymatic reporter unlocking (SHERLOCK) assay using the enzyme Cas13a from Leptotrichia wadei for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-the virus that causes coronavirus disease 2019 (COVID-19)-in 154 nasopharyngeal and throat swab samples collected at Siriraj Hospital, Thailand. Within a detection limit of 42 RNA copies per reaction, SHERLOCK was 100% specific and 100% sensitive with a fluorescence readout, and 100% specific and 97% sensitive with a lateral-flow readout.

A Minimized Chemoenzymatic Cascade for Bacterial Luciferase in Bioreporter Applications.

Bacterial luciferase (Lux) catalyzes a bioluminescence reaction by using long-chain aldehyde, reduced flavin and molecular oxygen as substrates. The reaction can be applied in reporter gene systems for biomolecular detection in both prokaryotic and eukaryotic organisms. Because reduced flavin is unstable under aerobic conditions, another enzyme, flavin reductase, is needed to supply reduced flavin to the Lux-catalyzed reaction.

Microbial degradation of halogenated aromatics: molecular mechanisms and enzymatic reactions.

Halogenated aromatics are used widely in various industrial, agricultural and household applications. However, due to their stability, most of these compounds persist for a long time, leading to accumulation in the environment. Biological degradation of halogenated aromatics provides sustainable, low-cost and environmentally friendly technologies for removing these toxicants from the environment.

Addition of formate dehydrogenase increases the production of renewable alkane from an engineered metabolic pathway.

An engineered metabolic pathway consisting of reactions that convert fatty acids to aldehydes and eventually alkanes would provide a means to produce biofuels from renewable energy sources. The enzyme aldehyde-deformylating oxygenase (ADO) catalyzes the conversion of aldehydes and oxygen to alkanes and formic acid and uses oxygen and a cellular reductant such as ferredoxin (Fd) as co-substrates. In this report, we aimed to increase ADO-mediated alkane production by converting an unused by-product, formate, to a reductant that can be used by ADO.