Phenotypes, Genetics, and Estimated Prevalence of Focal Dermal Hypoplasia (Goltz Syndrome): A Single-Center Report.

BACKGROUND: Focal dermal hypoplasia (FDH), also known as Goltz syndrome, is a rare ectodermal dysplasia that primarily affects the skin, skeleton, and eyes. It is an X-linked dominant disorder, predominantly seen in females, caused by pathogenic variants in PORCN. METHODS: We characterized a case series of four genetically confirmed FDH patients (three females, one male) at Aarhus University Hospital, Denmark. We estimated the FDH prevalence from our local cohort and nationwide registry data. RESULTS: Three patients had characteristic dermatological findings suspicious for FDH and confirmed by targeted PORCN analysis. One patient had an atypical presentation with several malformations but only subtle skin changes and was diagnosed following trio exome-sequencing analysis. Skin atrophy with fat herniations and telangiectasias were typical cutaneous findings. Limb malformations included oligodactyly (cleft foot), syndactyly, and polydactyly. Eye abnormalities included coloboma and microphthalmos. Facial dysmorphology was defined by asymmetry, thin upper lip, and malformed ears. One patient developed a giant cell bone tumor, which is a rare feature of FDH. Dental findings included enamel hypoplasia with vertical grooving and irregular crowns. Four PORCN variants were identified, including three not previously reported in the literature.We estimated a regional point prevalence in Western Denmark of 1.6 cases per million population (95% confidence intervals (CI): 0.7-3.7 per million) and a nationwide registry-based point prevalence of 1.2 cases per million population (95% CI: 0.6-2.4 per million). CONCLUSIONS: FDH is an extremely rare and complex multisystem disorder of variable presentation, which requires close multidisciplinary collaboration for diagnosis and patient care.

Accumulation of Cerebrospinal Fluid, Ventricular Enlargement, and Cerebral Folate Metabolic Errors Unify a Diverse Group of Neuropsychiatric Conditions Affecting Adult Neocortical Functions.

Cerebrospinal fluid (CSF) is a fluid critical to brain development, function, and health. It is actively secreted by the choroid plexus, and it emanates from brain tissue due to osmolar exchange and the constant contribution of brain metabolism and astroglial fluid output to interstitial fluid into the ventricles of the brain. CSF acts as a growth medium for the developing cerebral cortex and a source of nutrients and signalling throughout life. Together with perivascular glymphatic and interstitial fluid movement through the brain and into CSF, it also acts to remove toxins and maintain metabolic balance. In this study, we focused on cerebral folate status, measuring CSF concentrations of folate receptor alpha (FOLR1); aldehyde dehydrogenase 1L1, also known as 10-formyl tetrahydrofolate dehydrogenase (ALDH1L1 and FDH); and total folate. These demonstrate the transport of folate from blood across the blood-CSF barrier and into CSF (FOLR1 + folate), and the transport of folate through the primary FDH pathway from CSF into brain FDH + ve astrocytes. Based on our hypothesis that CSF flow, drainage issues, or osmotic forces, resulting in fluid accumulation, would have an associated cerebral folate imbalance, we investigated folate status in CSF from neurological conditions that have a severity association with enlarged ventricles. We found that all the conditions we examined had a folate imbalance, but these folate imbalances were not all the same. Given that folate is essential for key cellular processes, including DNA/RNA synthesis, methylation, nitric oxide, and neurotransmitter synthesis, we conclude that ageing or some form of trauma in life can lead to CSF accumulation and ventricular enlargement and result in a specific folate imbalance/deficiency associated with the specific neurological condition. We believe that addressing cerebral folate imbalance may therefore alleviate many of the underlying deficits and symptoms in these conditions.

Impact of a regulatory target and external factors on the waste efficiency of Italian municipalities.

Due to increasing consumption and urbanisation, urban waste management and recycling are a primary concern in Italy. Italian waste collection underwent significant reform with the introduction of a sorted collection target of 65% of total collected waste in Legislative Decree No. 152/2006. In this article, we analyse the effect of this regulatory target on the efficiency of waste collection in 275 Italian municipalities in the years 2016-2019. We estimate the coefficients of the cost efficiencies of the sorted and unsorted waste without assuming functional forms for the efficient frontier or the distribution of efficiency. Our findings suggest that municipalities that met the 65% sorted waste target demonstrated higher efficiency as costs increased, whereas those that failed to meet the target demonstrated higher inefficiency as costs increased. Strong effects emerged for population and urban economic development on the success of waste collection, whereas only marginal effects were observed for population density and city size. To improve the situation of municipalities that are not meeting the 65% target, we propose several policy measures, including 'neighbourhood solidarity'.

Arabidopsis thaliana Early Foliar Proteome Response to Root Exposure to the Rhizobacterium Pseudomonas simiae WCS417.

Pseudomonas simiae WCS417 is a plant growth-promoting rhizobacterium that improves plant health and development. In this study, we investigate the early leaf responses of Arabidopsis thaliana to WCS417 exposure and the possible involvement of formate dehydrogenase (FDH) in such responses. In vitro-grown A. thaliana seedlings expressing an FDH::GUS reporter show a significant increase in FDH promoter activity in their roots and shoots after 7 days of indirect exposure (without contact) to WCS417. After root exposure to WCS417, the leaves of FDH::GUS plants grown in the soil also show an increased FDH promoter activity in hydathodes. To elucidate early foliar responses to WCS417 as well as FDH involvement, the roots of A. thaliana wild-type Col and atfdh1-5 knock-out mutant plants grown in soil were exposed to WCS417, and proteins from rosette leaves were subjected to proteomic analysis. The results reveal that chloroplasts, in particular several components of the photosystems PSI and PSII, as well as members of the glutathione S-transferase family, are among the early targets of the metabolic changes induced by WCS417. Taken together, the alterations in the foliar proteome, as observed in the atfdh1-5 mutant, especially after exposure to WCS417 and involving stress-responsive genes, suggest that FDH is a node in the early events triggered by the interactions between A. thaliana and the rhizobacterium WCS417. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

The role of Tyr102 residue in the functioning of bacterial NAD+-dependent formate dehydrogenase of Pseudomonas sp. 101.

Once you have missed the first button …, you'll never manage to button up Johann Wolfgang von Goethe Formate oxidation is a final step of methanol oxidation in methylotrophic prokaryotes and is important for detoxification of formate in other organisms. The structural mechanism of the formate dehydrogenase (FDH) of Pseudomonas sp. 101 has been studied for about 30 years. In the active center of FDH, the oxidation of formic acid into carbon dioxide in a NAD+-dependent way takes place. Residues that form the active center of that enzyme, as well as those that form the so-called substrate channel, are engaged in the catalytic cycle. Our study allowed to characterize a new residue, Tyr102, involved in the work of the enzyme. This residue is located in the outer neck of the substrate channel (at the beginning of the path of the substrate to the active center) and acts as a "button" which connects two enzyme domains into an active, "buttoned up" conformation. Our study of the kinetic parameters of mutant enzymes has shown that Tyr102Phe substitution leads to an approximately 80-fold increase of the Michaelis constant relative to the native enzyme, unlike Phe311Trp and Phe311Tyr substitution of neighboring residue Phe311. Our analysis of the Tyr102Phe mutant in the open conformation by X-ray crystallography has shown that its overall fold remains almost the same as that of the native enzyme. Molecular dynamics simulations of the ternary complexes of the native FDH enzyme and its Tyr102Phe mutant showed that Tyr102Phe substitution results in the loss of an interdomain hydrogen bond between the Tyr102 and Gln313 residues, which, in turn, destabilizes the closed conformation and affects the isolation of the FDH active site from water molecules. Our structural investigations have shown that Tyr102Phe replacement also leads to the destruction of interdomain contacts of Phe102 with Phe311, Pro312 residues, and decreases the stability of the Leu103-Val127 beta bridge. Phylogenetic analysis also confirmed the importance of the Tyr102 residue for enzymes from the FDH family, in which it is absolutely conserved.

The challenges of using NAD+-dependent formate dehydrogenases for CO2 conversion.

In recent years, CO2 reduction and utilization have been proposed as an innovative solution for global warming and the ever-growing energy and raw material demands. In contrast to various classical methods, including chemical, electrochemical, and photochemical methods, enzymatic methods offer a green and sustainable option for CO2 conversion. In addition, enzymatic hydrogenation of CO2 into platform chemicals could be used to produce economically useful hydrogen storage materials, making it a win-win strategy. The thermodynamic and kinetic stability of the CO2 molecule makes its utilization a challenging task. However, Nicotine adenine dinucleotide (NAD+)-dependent formate dehydrogenases (FDHs), which have high selectivity and specificity, are attractive catalysts to overcome this issue and convert CO2 into fuels and renewable chemicals. It is necessary to improve the stability, cofactor necessity, and CO2 conversion efficiency of these enzymes, such as by combining them with appropriate hybrid systems. However, metal-independent, NAD+-dependent FDHs, and their CO2 reduction activity have received limited attention to date. This review outlines the CO2 reduction ability of these enzymes as well as their properties, reaction mechanisms, immobilization strategies, and integration with electrochemical and photochemical systems for the production of formic acid or formate. The biotechnological applications of FDH, future perspectives, barriers to CO2 reduction with FDH, and aspects that must be further developed are briefly summarized. We propose that constructing hybrid systems that include NAD+-dependent FDHs is a promising approach to convert CO2 and strengthen the sustainable carbon bio-economy.

Engineered formate dehydrogenase from Chaetomium thermophilum, a promising enzymatic solution for biotechnical CO2 fixation.

OBJECTIVES: Formate dehydrogenases (FDHs) are NAD(P)H-dependent enzymes that catalyse the reversible oxidation of formate to CO2. The main goal was to use directed evolution to obtain variants of the FDH from Chaetomium thermophilum (CtFDH) with enhanced reduction activity in the conversion of CO2 into formic acid. RESULTS: Four libraries were constructed targeting five residues in the active site. We identified two variants (G93H/I94Y and R259C) with enhanced reduction activity which were characterised in the presence of both aqueous CO2(g) and HCO3-. The A1 variant (G93H/I94Y) showed a 5.4-fold increase in catalytic efficiency (kcat/KM) compared to that of the wild-type for HCO3- reduction. The improved biocatalysts were also applied as a coupled cofactor recycling system in the enantioselective oxidation of 4-phenyl-2-propanol catalysed by the alcohol dehydrogenase from Streptomyces coelicolor A3 (ScADH). Conversions in these reactions increased from 56 to 91% when the A1 variant was used instead of wild-type CtFDH. CONCLUSIONS: Two variants presenting up to five-fold increase in catalytic efficiency and kcat were obtained and characterised. They constitute a promising enzymatic alternative for CO2 utilization and will serve as scaffolds to be further developed in order to meet industrial requirements.

The influence of the shape of Au nanoparticles on the catalytic current of fructose dehydrogenase.

Graphite electrodes were modified with triangular (AuNTrs) or spherical (AuNPs) nanoparticles and further modified with fructose dehydrogenase (FDH). The present study reports the effect of the shape of these nanoparticles (NPs) on the catalytic current of immobilized FDH pointing out the different contributions on the mass transfer-limited and kinetically limited currents. The influence of the shape of the NPs on the mass transfer-limited and the kinetically limited current has been proved by using two different methods: a rotating disk electrode (RDE) and an electrode mounted in a wall jet flow-through electrochemical cell attached to a flow system. The advantages of using the wall jet flow system compared with the RDE system for kinetic investigations are as follows: no need to account for substrate consumption, especially in the case of desorption of enzyme, and studies of product-inhibited enzymes. The comparison reveals that virtually identical results can be obtained using either of the two techniques. The heterogeneous electron transfer (ET) rate constants (kS) were found to be 3.8 ± 0.3 s-1 and 0.9 ± 0.1 s-1, for triangular and spherical NPs, respectively. The improvement observed for the electrode modified with AuNTrs suggests a more effective enzyme-NP interaction, which can allocate a higher number of enzyme molecules on the electrode surface. Graphical abstract The shape of gold nanoparticles has a crucial effect on the catalytic current related to the oxidation of D-(-)-fructose to 5-keto-D-(-)-fructose occurring at the FDH-modified electrode surface. In particular, AuNTrs have a higher effect compared with the spherical one.

Over-expression of the Arabidopsis formate dehydrogenase in chloroplasts enhances formaldehyde uptake and metabolism in transgenic tobacco leaves.

MAIN CONCLUSION: Over-expression of AtFDH controlled by the promoter of Rubisco small subunit in chloroplasts increases formaldehyde uptake and metabolism in tobacco leaves. Our previous study showed that formaldehyde (HCHO) uptake and resistance in tobacco are weaker than in Arabidopsis. Formate dehydrogenase in Arabidopsis (AtFDH) is a key enzyme in HCHO metabolism by oxidation of HCOOH to CO2, which enters the Calvin cycle to be assimilated into glucose. HCHO metabolic mechanism in tobacco differs from that in Arabidopsis. In this study, AtFDH was over-expressed in the chloroplasts of transgenic tobacco using a light inducible promoter. 13C-NMR analysis showed that the carbon flux from H13CHO metabolism was not introduced into the Calvin cycle to produce glucose in transgenic tobacco leaves. However, the over-expression of AtFDH significantly enhanced the HCHO metabolism in transgenic leaves. Consequently, the productions of [4-13C]Asn, [3-13C]Gln, [U-13C]oxalate, and H13COOH were notably greater in transgenic leaves than in non-transformed leaves after treatment with H13CHO. The increased stomatal conductance and aperture in transgenic leaves might be ascribed to the increased yield of oxalate in the guard cells with over-expressed AtFDH in chloroplasts. Accordingly, the transgenic plants exhibited a stronger capacity to absorb gaseous HCHO. Furthermore, the higher proline content in transgenic leaves compared with non-transformed leaves under HCHO stress might be attributable to the excess formate accumulation and Gln production. Consequently, the HCHO-induced oxidative stress was reduced in transgenic leaves.

The influence of pH and divalent/monovalent cations on the internal electron transfer (IET), enzymatic activity, and structure of fructose dehydrogenase.

We report on the influence of pH and monovalent/divalent cations on the catalytic current response, internal electron transfer (IET), and structure of fructose dehydrogenase (FDH) by using amperometry, spectrophotometry, and circular dichroism (CD). Amperometric measurements were performed on graphite electrodes, onto which FDH was adsorbed and the effect on the response current to fructose was investigated when varying the pH and the concentrations of divalent/monovalent cations in the contacting buffer. In the presence of 10 mM CaCl2, a current increase of up to ≈ 240% was observed, probably due to an intra-complexation reaction between Ca2+ and the aspartate/glutamate residues found at the interface between the dehydrogenase domain and the cytochrome domain of FDH. Contrary to CaCl2, addition of MgCl2 did not show any particular influence, whereas addition of monovalent cations (Na+ or K+) led to a slight linear increase in the maximum response current. To complement the amperometric investigations, spectrophotometric assays were carried out under homogeneous conditions in the presence of a 1-electron non-proton-acceptor, cytochrome c, or a 2-electron-proton acceptor, 2,6-dichloroindophenol (DCIP), respectively. In the case of cytochrome c, it was possible to observe a remarkable increase in the absorbance up to 200% when 10 mM CaCl2 was added. However, by further increasing the concentration of CaCl2 up to 50 mM and 100 mM, a decrease in the absorbance with a slight inhibition effect was observed for the highest CaCl2 concentration. Addition of MgCl2 or of the monovalent cations shows, surprisingly, no effect on the electron transfer to the electron acceptor. Contrary to the case of cytochrome c, with DCIP none of the cations tested seem to affect the rate of catalysis. In order to correlate the results obtained by amperometric and spectrophotometric measurements, CD experiments have been performed showing a great structural change of FDH when increasing the concentration CaCl2 up to 50 mM, at which the enzyme molecules start to agglomerate, hindering the substrate access to the active site probably due to a chelation reaction occurring at the enzyme surface with the glutamate/aspartate residues. Graphical Abstract Fructose dehydrogenase (FDH) consists of three subunits, but only two are involved in the electron transfer process: (I) 2e-/2H+ fructose oxidation, (II) internal electron transfer (IET), (III) direct electron transfer (DET) through 2 heme c; FDH activity either in solution or when immobilized onto an electrode surface is enhanced about 2.5-fold by adding 10 mM CaCl2 to the buffer solution, whereas MgCl2 had an "inhibition" effect. Moreover, the additions of KCl or NaCl led to a slight current increase.

Neonatal hydrocephalus is a result of a block in folate handling and metabolism involving 10-formyltetrahydrofolate dehydrogenase.

Folate is vital in a range of biological processes and folate deficiency is associated with neurodevelopmental disorders such as neural tube defects and hydrocephalus (HC). 10-formyl-tetrahydrofolate-dehydrogenase (FDH) is a key regulator for folate availability and metabolic interconversion for the supply of 1-carbon groups. In previous studies, we found a deficiency of FDH in CSF associated with the developmental deficit in congenital and neonatal HC. In this study, we therefore aimed to investigate the role of FDH in folate transport and metabolism during the brain development of the congenital hydrocephalic Texas (H-Tx) rat and normal (Sprague-Dawley) rats. We show that at embryonic (E) stage E18 and E20, FDH-positive cells and/or vesicles derived from the cortex can bind methyl-folate similarly to folate receptor alpha, the main folate transporter. Hydrocephalic rats expressed diminished nuclear FDH in both liver and brain at all postnatal (P) ages tested (P5, P15, and P20) together with a parallel increase in hepatic nuclear methyl-folate at P5 and cerebral methylfolate at P15 and P20. A similar relationship was found between FDH and 5-methyl cytosine, the main marker for DNA methylation. The data indicated that FDH binds and transports methylfolate in the brain and that decreased liver and brain nuclear expression of FDH is linked with decreased DNA methylation which could be a key factor in the developmental deficits associated with congenital and neonatal HC. Folate deficiency is associated with neurodevelopmental disorders such as neural tube defects and hydrocephalus. 10-formyl-tetrahydrofolate-dehydrogenase (FDH) is a key regulator for folate availability and metabolic interconversion. We show that FDH binds and transports methylfolate in the brain. Moreover, we found that a deficiency of FDH in the nucleus of brain and liver is linked with decreased DNA methylation which could be a key factor in the developmental deficits associated with congenital and neonatal hydrocephalus cells.

Knocking down 10-Formyltetrahydrofolate dehydrogenase increased oxidative stress and impeded zebrafish embryogenesis by obstructing morphogenetic movement.

BACKGROUND: Folate is an essential nutrient for cell survival and embryogenesis. 10-Formyltetrahydrofolate dehydrogenase (FDH) is the most abundant folate enzyme in folate-mediated one-carbon metabolism. 10-Formyltetrahydrofolate dehydrogenase converts 10-formyltetrahydrofolate to tetrahydrofolate and CO2, the only pathway responsible for formate oxidation in methanol intoxication. 10-Formyltetrahydrofolate dehydrogenase has been considered a potential chemotherapeutic target because it was down-regulated in cancer cells. However, the normal physiological significance of 10-Formyltetrahydrofolate dehydrogenase is not completely understood, hampering the development of therapeutic drug/regimen targeting 10-Formyltetrahydrofolate dehydrogenase. METHODS: 10-Formyltetrahydrofolate dehydrogenase expression in zebrafish embryos was knocked-down using morpholino oligonucleotides. The morphological and biochemical characteristics of fdh morphants were examined using specific dye staining and whole-mount in-situ hybridization. Embryonic folate contents were determined by HPLC. RESULTS: The expression of 10-formyltetrahydrofolate dehydrogenase was consistent in whole embryos during early embryogenesis and became tissue-specific in later stages. Knocking-down fdh impeded morphogenetic movement and caused incorrect cardiac positioning, defective hematopoiesis, notochordmalformation and ultimate death of morphants. Obstructed F-actin polymerization and delayed epiboly were observed in fdh morphants. These abnormalities were reversed either by adding tetrahydrofolate or antioxidant or by co-injecting the mRNA encoding 10-formyltetrahydrofolate dehydrogenase N-terminal domain, supporting the anti-oxidative activity of 10-formyltetrahydrofolate dehydrogenase and the in vivo function of tetrahydrofolate conservation for 10-formyltetrahydrofolate dehydrogenase N-terminal domain. CONCLUSIONS: 10-Formyltetrahydrofolate dehydrogenase functioned in conserving the unstable tetrahydrofolate and contributing to the intracellular anti-oxidative capacity of embryos, which was crucial in promoting proper cell migration during embryogenesis. GENERAL SIGNIFICANCE: These newly reported tetrahydrofolate conserving and anti-oxidative activities of 10-formyltetrahydrofolate dehydrogenase shall be important for unraveling 10-formyltetrahydrofolate dehydrogenase biological significance and the drug development targeting 10-formyltetrahydrofolate dehydrogenase.

Ubiquitin-like protein MNSFß covalently binds to cytosolic 10-formyltetrahydrofolate dehydrogenase and regulates thymocyte function.

MNSFß is a ubiquitously expressed member of the ubiquitin-like family that has been involved in various biological functions. Previous studies have demonstrated that MNSFß covalently binds to various target proteins including Bcl-G, a proapoptotic protein. In this study, we purified a 115 kDa MNSFß adduct from murine liver lysates by sequential chromatography on DEAE and anti-MNSFß IgG-conjugated Sepharose in the presence of ATP. MALDI-TOF MS fingerprinting revealed that this MNSFß adduct consists of an 8.5 kDa MNSFß and 10-formyltetrahydrofolate dehydrogenase (FDH), an abundant enzyme of folate metabolism. Interestingly, MNSFß preferably binds to cytosolic but not mitochondrial FDH. Fingerprinting analysis of the MNSFß adduct demonstrate that MNSFß conjugates to cytosolic FDH with a linkage between the C-terminal Gly74 and Lys72. The 115 kDa MNSFß/FDH complex was not expressed in any of the tissues examined, indicating that this adduct formation is not ubiquitous. We found that MNSFß/FDH complex formation was induced by dexamethasone in thymocytes. Double knockdown of MNSFß and FDH strongly reduced dexamethasone-induced apoptosis. Collectively, MNSFß/FDH complex formation may positively regulate apoptosis in thymocytes.

mecA and fdh: markers of pathogenicity and commensalism in Staphylococcus epidermidis of pediatric origin from Pakistan.

Staphylococcus epidermidis is an opportunistic bacterial pathogen. The study screened isolates of S. epidermidis of pediatric origin for genetic markers of discriminatory potential. 103 isolates (n = 75 clinical; n = 28 community) were screened for methicillin resistance (mecA), formate dehydrogenase (fdh) and an array of virulence factors through multiplex PCR and Congo red assay. The isolates were typed in four distinct categories, based on the presence of selected virulent factors. The type A clinical isolates carrying icaADBC operon (n = 22; 29.3%, P = 0.117) were not significantly differentiating the origin of isolates. The type B clinical isolates representing methicillin resistant S. epidermidis (MRSE) (n = 73; 97.3%, P < 0.00001) and the type C clinical isolates lacking formate dehydrogenase fdh (n = 62; 82.6%, P < 0.00001) were having significant discriminatory potential of clinical isolates, respectively. All type D community isolates were carrying fdh (n = 28; 100%, P < 0.00001). MecA and fdh are significant differential markers of pathogenicity and commensalism in S. epidermidis of pediatric origin.

Tri-enzyme fusion of tryptophan halogenase achieves a concise strategy for coenzyme self-sufficiency and the continuous halogenation of L-tryptophan.

The halogenase-based catalysis is one of the most environmentally friendly methods for the synthesis of halogenated products, among which flavin-dependent halogenases (FDHs) have attracted great interest as one of the most promising biocatalysts due to the remarkable site-selectivity and wide substrate range. However, the complexity of constructing the NAD+-NADH-FAD-FADH2 bicoenzyme cycle system has affected the engineering applications of FDHs. In this work, a coenzyme self-sufficient tri-enzyme fusion was constructed and successfully applied to the continuous halogenation of L-tryptophan. SpFDH was firstly identified derived from Streptomyces pratensis, a highly selective halogenase capable of generating 6-chloro-tryptophan from tryptophan. Then, using gene fusion technology, SpFDH was fused with glucose dehydrogenase (GDH) and flavin reductase (FR) to form a tri-enzyme fusion, which increased the yield by 1.46-fold and making the coenzymes self-sufficient. For more efficient halogenation of L-tryptophan, a continuous halogenation bioprocess of L-tryptophan was developed by immobilizing the tri-enzyme fusion and attaching it to a continuous catalytic device, which resulted in a reaction yield of 97.6% after 12 h reaction. An FDH from S. pratensis was successfully applied in the halogenation and our study provides a concise strategy for the preparation of halogenated tryptophan mediated by multienzyme cascade catalysis.

Development of Cupriavidus necator H16 as a host for heterologous production of formate dehydrogenase I of Methylorubrum extorquens: Possibilities and limitations.

The discovery of formate dehydrogenase (Me-FDH1) from Methylorubrum extorquens has provided an avenue for sustainable CO2 fixation and utilization. However, the mass production of Me-FDH1 is challenging due to the presence of its unique tungsto-bis-metalopterin guanine dinucleotide (W-bis-MGD) cofactor, limiting its practical applications. In this study, C. necator H16 is proposed as a host for the large-scale production of Me-FDH1, utilizing fructose as a carbon source and its inherent machinery for cofactor synthesis. In a minimal salt medium, C. necator H16 could produce active Me-FDH1, which exhibited a specific activity of 80 to 100 U/mg for CO2 conversion to formate. In fed batch bioreactor experiments, approximately 50 g CDW/L (cell dry weight/L) and 10,000 U/L Me-FDH1 were achieved within 50 h. This study highlights C. necator H16 as the recombinant host for Me-FDH1, paving the way for the future development of efficient mass-production methods for this crucial enzyme.

Aß-binding with alcohol dehydrogenase drives Alzheimer's disease pathogenesis: A review.

Although Alzheimer's disease (AD) characterized with senile plaques and neurofibrillary tangles has been found for over 100 years, its molecular mechanisms are ambiguous. More worsely, the developed medicines targeting amyloid-beta (Aß) and/or tau hyperphosphorylation did not approach the clinical expectations in patients with moderate or severe AD until now. This review unveils the role of a vicious cycle between Aß-derived formaldehyde (FA) and FA-induced Aß aggregation in the onset course of AD. Document evidence has shown that Aß can bind with alcohol dehydrogenase (ADH) to form the complex of Aß/ADH (ABAD) and result in the generation of reactive oxygen species (ROS) and aldehydes including malondialdehyde, hydroxynonenal and FA; in turn, ROS-derived H2O2 and FA promotes Aß self-aggregation; subsequently, this vicious cycle accelerates neuron death and AD occurrence. Especially, FA can directly induce neuron death by stimulating ROS generation and tau hyper hyperphosphorylation, and impair memory by inhibiting NMDA-receptor. Recently, some new therapeutical methods including inhibition of ABAD activity by small molecules/synthetic polypeptides, degradation of FA by phototherapy or FA scavengers, have been developed and achieved positive effects in AD transgenic models. Thus, breaking the vicious loop may be promising interventions for halting AD progression.

Improvement of ethanol productivity and energy efficiency by degradation of inhibitors using recombinant Zymomonas mobilis (pHW20a-fdh).

Toxic compounds, such as formic acid, furfural, and hydroxymethylfurfural (HMF) generated during pretreatment of corn stover (CS) at high temperature and low pH, inhibit growth of Zymomonas mobilis and lower the conversion efficiency of CS to biofuel and other products. The inhibition of toxic compounds is considered as one of the major technical barriers in the lignocellulose bioconversion. In order to detoxify and/or degrade these toxic compounds by the model ethanologenic strain Z. mobilis itself in situ the fermentation medium, we constructed a recombinant Z. mobilis ZM4 (pHW20a-fdh) strain that is capable of degrading toxic inhibitor, formate. This is accomplished by cloning heterologous formate dehydrogenase gene (fdh) from Saccharomyces cerevisiae and by coupling this reaction of NADH regeneration reaction system with furfural and HMF degradation in the recombinant Z. mobilis strain. The NADH regeneration reaction also improved both the energy efficiency and cell physiological activity of the recombinant organism, which were definitely confirmed by the improved cell growth, ethanol yield, and ethanol productivity during fermentation with CS hydrolysate.

Focal Dermal Hypoplasia Associated With Lymphedema: A Case Report From Saudi Arabia.

Focal dermal hypoplasia (FDH), also known as Goltz syndrome, is a rare syndrome described in the literature. Patchy skin hypoplasia is the most evident sign. Hyperpigmentation, hypopigmentation, papillomas, limb defects, and orofacial manifestations have also been reported. A 12-year-old Saudi girl with unremarkable family history presented with FDH. The diagnosis was confirmed using a genetic study. Physical examination revealed asymmetrical streaks of vermiculate dermal atrophy, telangiectasia with hyperpigmentation, and hypopigmentation on the left half of the face, trunk, and bilateral extremities. It appears along Blashko lines. No mental impairment was observed. Intraoral examination generalized plaque-induced gingivitis with erythematous gingival hyperplasia. Examination of the teeth showed generalized enamel hypoplasia with abnormal tooth formations, malalignment, microdontia, spacing and tilting, and minimal caries. As reported cases of FDH are rare worldwide, this syndrome is yet to be fully understood. As the manifestation of the syndrome varies among cases, the management of each case is unique. This emphasizes the importance of reporting cases of FDH.

FDH/Hases-S-chain mediated electron redistributing in Citrobacter freundii JH@FeS during degradation of sulfamethoxazole and nitrate.

Considering the negligent degradation of sulfamethoxazole (SMX) by Citrobacter freundii JH, the incorporation of bio-FeS could initiate the SMX biodegradation to 0.0444 (S-FeS), and further to 0.0564 mg L-1 mg-1 protein d-1 (SN-FeS) when coexisted with nitrate. Electrochemical (LSV, I-t, DPV, EIS and EDC) and respiratory inhibition experiments clarified that the bio-FeS could greatly switch/redistribute electron transmembrane-transfer from intracellular to extracellular mainly via FDH/Hases-S-chain, as revealed by the significant increase of ipa-FDH/Hases/ipa-FC-Cyts and ipc-FDH/Hases/ipc-FC-Cyts (from 1.09 and 1.07 (SN-native) to 1.50 and 3.58 (SN-FeS)), while nitrate (linear fitting with NADH (R2 = 0.9903)) mainly intensified CoQ-L-chain related INET from Complex I to CoQ to compensate for the electronic competition with SMX. SN-FeS system detoxified the SMX on microbial metabolism (such as membrane rupture and oxidative stress induction) with high SOD activity (737.93 U gFW-1). Structural equation modeling indicated that bio-FeS up-regulated PMF-mediated ATP synthesis (PPMF-ATPs from 0.12 (SN-native) to 0.74 (SN-FeS)) and PMF-mediated NADH (PPMF-NADH from -0.72 (SN-native) to 0.63 (SN-FeS)), and the nitrate addition intensified this positive feedback. Overall, this study provides a new perspective for bionanoparticles via electron transfer/redistribution to detoxify and launch the antibiotics biodegradation in ecological environment.