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1.
Biochimie ; 2024 Jul 20.
Article in English | MEDLINE | ID: mdl-39038731

ABSTRACT

This study examines how FOF1-ATPase, hydrogenases (Hyd-1 and Hyd-2), and potassium transport systems (TrkA) interact to maintain the proton motive force (pmf) in E. coli during fermentation of different glucose concentrations (2 g L-1 and 8 g L-1). Our findings indicate that mutants lacking the hyaA-hyaC genes exhibited a 30 % increase in total proton flux compared to the wild type when grown with 2 g L-1 glucose. This has been observed during assays where similar glucose levels were supplemented. Disruptions in proton pumping, particularly in hyaB and hyaC single mutants, led to increased potassium uptake. The hyaB mutant showed a threefold increase in the contribution of FOF1-ATPase to proton flux, suggesting a significant role for Hyd-1 in proton translocation. In the hybC mutant grown in 2 g L-1 glucose conditions, DCCD-sensitive fluxes decreased by 70 %, indicating critical role of Hyd-2 in proton transport and FOF1 function. When cells were grown with 8 g L-1 glucose, the 2H+/1K+ ratio was significantly disturbed in both wild type and mutants. Despite these perturbances, mutants with disruptions in Hyd-1 and Hyd-2 maintained constant FOF1 function, suggesting that this enzyme remains stable in glucose-rich environments. These results provide valuable insights into how Hyd-1 and Hyd-2 contribute to the regulation of ion transport, particularly proton translocation, in response to glucose concentration. Our study uncovered potential complementary mechanisms between Hyd-1 and Hyd-2 subunits, suggesting a complex interplay between these enzymes via metabolic cross talk with FOF1 in response to glucose concentrations to maintain pmf.

2.
Plant Cell Rep ; 43(5): 119, 2024 Apr 17.
Article in English | MEDLINE | ID: mdl-38632145

ABSTRACT

KEY MESSAGE: Mutants lacking functional HYD2 homoeologs showed improved seedling growth, but comparable or increased susceptibility to salt stress in tillering plants, suggesting a developmentally restricted role of HYD2 in salt response. Salinity stress threatens global food security by reducing the yield of staple crops such as wheat (Triticum ssp.). Understanding how wheat responds to salinity stress is crucial for developing climate resilient varieties. In this study, we examined the interplay between carotenoid metabolism and the response to salt (NaCl) stress, a specific form of salinity stress, in tetraploid wheat plants with mutations in carotenoid ß-hydroxylase 1 (HYD1) and HYD2. Our investigation encompassed both the vulnerable seedling stage and the more developed tillering stage of wheat plant growth. Mutant combinations lacking functional HYD2 homoeologs, including hyd-A2 hyd-B2, hyd-A1 hyd-A2 hyd-B2, hyd-B1 hyd-A2 hyd-B2, and hyd-A1 hyd-B1 hyd-A2 hyd-B2, had longer first true leaves and slightly enhanced root growth during germination under salt stress compared to the segregate wild-type (control) plants. Interestingly, these mutant seedlings also showed decreased levels of neoxanthin and violaxanthin (xanthophylls derived from ß-carotene) and an increase in ß-carotene in roots. However, tillering hyd mutant and segregate wild-type plants generally did not differ in their height, tiller count, and biomass production under acute or prolonged salt stress, except for decreases in these parameters observed in the hyd-A1 hyd-B1 hyd-A2 hyd-B2 mutant that indicate its heightened susceptibility to salt stress. Taken together, these findings suggest a significant, yet developmentally restricted role of HYD2 homoeologs in salt-stress response in tetraploid wheat. They also show that hyd-A2 hyd-B2 mutant plants, previously demonstrated for possessing enriched nutritional (ß-carotene) content, maintain an unimpaired ability to withstand salt stress.


Subject(s)
Salt Stress , Seedlings , Triticum , beta Carotene , beta Carotene/metabolism , Carotenoids/metabolism , Salinity , Salt Stress/genetics , Seedlings/metabolism , Tetraploidy , Triticum/genetics , Plant Proteins/genetics , Plant Proteins/metabolism , Gene Expression Regulation, Plant
3.
ChemistryOpen ; : e202400062, 2024 Apr 12.
Article in English | MEDLINE | ID: mdl-38607955

ABSTRACT

The hydrodesulfurization (HDS) process is widely used in the industry to eliminate sulfur compounds from fuels. However, removing dibenzothiophene (DBT) and its derivatives is a challenge. Here, the key aspects that affect the efficiency of catalysts in the HDS of DBT were investigated using machine learning (ML) algorithms. The conversion of DBT and selectivity was estimated by applying Lasso, Ridge, and Random Forest regression techniques. For the estimation of conversion of DBT, Random Forest and Lasso offer adequate predictions. At the same time, regularized regressions have similar outcomes, which are suitable for selectivity estimations. According to the regression coefficient, the structural parameters are essential predictors for selectivity, highlighting the pore size, and slab length. These properties can connect with aspects like the availability of active sites. The insights gained through ML techniques about the HDS catalysts agree with the interpretations of previous experimental reports.

4.
ACS Appl Mater Interfaces ; 16(17): 22066-22078, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38629710

ABSTRACT

Development of crystalline porous materials for selective CO2 adsorption and storage is in high demand to boost the carbon capture and storage (CCS) technology. In this regard, we have developed a ß-keto enamine-based covalent organic framework (VM-COF) via the Schiff base polycondensation technique. The as-synthesized VM-COF exhibited excellent thermal and chemical stability along with a very high surface area (1258 m2 g-1) and a high CO2 adsorption capacity (3.58 mmol g-1) at room temperature (298 K). The CO2/CH4 and CO2/H2 selectivities by the IAST method were calculated to be 10.9 and 881.7, respectively, which were further experimentally supported by breakthrough analysis. Moreover, theoretical investigations revealed that the carbonyl-rich sites in a polymeric backbone have higher CO2 binding affinity along with very high binding energy (-39.44 KJ mol-1) compared to other aromatic carbon-rich sites. Intrigued by the best CO2 adsorption capacity and high CO2 selectivity, we have utilized the VM-COF for biogas purification produced by the biofermentation of municipal waste. Compared with the commercially available activated carbon, VM-COF exhibited much better purification ability. This opens up a new opportunity for the creation of functionalized nanoporous materials for the large-scale purification of waste-generated biogases to address the challenges associated with energy and the environment.

5.
AIMS Microbiol ; 9(4): 724-737, 2023.
Article in English | MEDLINE | ID: mdl-38173976

ABSTRACT

Escherichia coli performs mixed-acid fermentation and produces molecular hydrogen (H2) via reversible hydrogenases (Hyd). H2 producing activity was investigated during hyper- and hypo-osmotic stress conditions when a mixture of carbon sources (glucose and glycerol) was fermented at different pHs. Hyper-osmotic stress decreased H2 production rate (VH2) ~30 % in wild type at pH 7.5 when glucose was supplemented, while addition of formate stimulated VH2 ~45% compared to hypo-stress conditions. Only in hyfG in formate assays was VH2 inhibited ~25% compared to hypo-stress conditions. In hypo-stress conditions addition of glycerol increased VH2 ~2 and 3 fold in hybC and hyfG mutants, respectively, compared to wild type. At pH 6.5 hyper-osmotic stress stimulated VH2 ~2 fold in all strains except hyaB mutant when glucose was supplemented, while in formate assays significant stimulation (~3 fold) was determined in hybC mutant. At pH 5.5 hyper-osmotic stress inhibited VH2 ~30% in wild type when glucose was supplemented, but in formate assays it was stimulated in all strains except hyfG. Taken together, it can be concluded that, depending on external pH and absence of Hyd enzymes in stationary-phase-grown osmotically stressed E. coli cells, H2 production can be stimulated significantly which can be applied in developing H2 production biotechnology.

6.
Antioxidants (Basel) ; 11(9)2022 Aug 28.
Article in English | MEDLINE | ID: mdl-36139752

ABSTRACT

Liver damage severity depends on both the dose and the exposure duration. Oxidative stress may increase the Ochratoxine-A (OTA) hepatotoxicity and many antioxidants may counteract toxic liver function. The present study aims to investigate the hepatoprotective potential of Azadirachta indicaA (A. indica; neem oil) seed oil to reduce acute oxidative disorders and residual OTA toxicity in a 28-day experimental model. The activity of antioxidant and hepatic enzymes, cytokines and the levels of oxidative stress biomarkers -MDA, GSPx, Hydroxiproline, GST, PCC, AGEs, PGC-1, and STIR-1 were analyzed by ELISA. The free radicals ROS and RNS levels were measured by EPR. The protective effects were studied in BALB/C mice treated with A. indica seed oil (170 mg/kg), alone and in combination with OTA (1.25 mg/kg), by gavage daily for 28 days. At the end of the experiment, mice treated with OTA showed changes in liver and antioxidant enzymes, and oxidative stress parameters in the liver and blood. A. indica oil significantly reduced oxidative stress and lipid peroxidation compared to the OTA group. In addition, the hepatic histological evaluation showed significant adipose tissue accumulation in OTA-treated tissues, while treatment with 170 mg/kg A. indica oil showed moderate adipose tissue accumulation.

7.
Acta Pharm Sin B ; 11(6): 1592-1606, 2021 Jun.
Article in English | MEDLINE | ID: mdl-34221870

ABSTRACT

HYD-PEP06, an endostatin-modified polypeptide, has been shown to produce effective anti-colorectal carcinoma effects through inhibiting epithelial-mesenchymal transition (EMT). However, whether HYD-PEP06 has similar suppressive effect on hepatocellular carcinoma (HCC) remained unknown. In this study, HYD-PEP06 inhibited metastasis and EMT but not proliferation in vitro. Cignal finder pathway reporter array and Western blot analysis revealed that HYD-PEP06 suppressed HCCLM3 cell metastasis and EMT by inhibiting the PI3K/AKT pathway. Moreover, HYD-PEP06 exerted anti-metastasis effects in HepG2 cancer stem-like cells (CSCs) via suppressing the WNT/ß-catenin signaling pathway. Finally, in HCCLM3 tumor-bearing BALB/c nu/nu nude mice, HYD-PEP06 substantially suppressed tumor growth, lung metastasis and HCC progress. Our results suggest that HYD-PEP06 inhibits the metastasis and EMT of HCC and CSCs as well, and thus has the potential as an agent for HCC treatment.

8.
Bioengineered ; 12(1): 1351-1359, 2021 12.
Article in English | MEDLINE | ID: mdl-33904385

ABSTRACT

RNA interference (RNAi) was used to investigate the role of epididymal vascular endothelial growth factor (VEGF) gene expression on sperm hyaluronidase (HYD) in a rat model of arsenic poisoning and to identify a new gene therapy target for male infertility caused by arsenic poisoning. The Rat model of chronic arsenic poisoning was established. And we found that positive expression of VEGF and VEGF receptor 2 (VEGFR2) was observed by Immunohistochemical staining in the epididymal tissues of arsenic-exposed rats. Subsequently, VEGF-shRNA-1, VEGF-shRNA-2 and VEGF shRNA-3 expression vectors containing epididymal VEGF-shRNA lentivirus were constructed and injected into the bilateral epididymis of each group of rats (Control group, NC-shRNA negative infection group, VEGF-shRNA-1 group, VEGF-shRNA-2 group, VEGF-shRNA-3 group) (n = 10 per group). Compared with the negative infection group and the normal control group, the expression of VEGF and VEGFR2 mRNA and protein levels were significantly decreased following epididymal infection. In addition, the HYD activity was all significantly lower than that in the normal control group and the negative infection group. Taken together, epididymal VEGF gene silencing may inhibit the activity of sperm HYD through downregulating VEGFR2.


Subject(s)
Arsenic Poisoning/enzymology , Arsenic Poisoning/genetics , Down-Regulation , Epididymis/metabolism , Gene Silencing , Hyaluronoglucosaminidase/metabolism , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor Receptor-2/genetics , Animals , Male , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Small Interfering/metabolism , Rats, Sprague-Dawley , Vascular Endothelial Growth Factor A/metabolism , Vascular Endothelial Growth Factor Receptor-2/metabolism
9.
J Nutr Sci ; 10: e12, 2021.
Article in English | MEDLINE | ID: mdl-33889395

ABSTRACT

Vitamin D insufficiency is associated with various disease processes. We determined whether consumption of a diet supplemented with HyD®, a 25-hydroxycholecalciferol (25(OH)D3) source, would safely increase plasma 25(OH)D3 concentrations in Golden Retrievers with low vitamin D status. We hypothesised that dietary supplementation with HyD® would rapidly increase and sustain plasma 25(OH)D3 levels in healthy Golden Retrievers with low vitamin D status compared with supplementation with vitamin D3. Of fifty-seven privately owned dogs recruited with written owner consent, eighteen dogs with low vitamin D status were identified and sorted between two groups to have similar initial plasma 25(OH)D3 concentrations, sex distributions, ages and body weights. Dogs of each group were fed a dry dog food supplemented with either 16 µg/kg of 25(OH)D3 as HyD® (n 10) or 81 µg/kg of cholecalciferol (D3) (n 8) for 4 months. Plasma 25(OH)D3 concentrations were determined monthly. A significant time effect (P < 0⋅001) and time by group interaction (P = 0⋅0045) were found for monthly determined plasma 25(OH)D3 concentrations. Dogs fed the HyD®-supplemented diet experienced a 40⋅5 % rise in plasma 25(OH)D3 values after 1 month (P < 0⋅001) and no change thereafter. Plasma 25(OH)D3 values of dogs supplemented with vitamin D3 did not increase (P > 0⋅05) and were less than values of dogs supplemented with HyD® (P = 0⋅044). With few exceptions, average haematologic, biochemical and urinalyses results remained within the reference range for both groups. Dietary supplementation with HyD® is sufficient to safely increase and sustain plasma 25(OH)D3 levels in healthy dogs.


Subject(s)
Calcifediol , Diet , Dietary Supplements , Vitamin D , Animals , Calcifediol/administration & dosage , Cholecalciferol , Diet/veterinary , Dogs , Vitamin D/blood , Vitamins
10.
Acta Pharmaceutica Sinica B ; (6): 1592-1606, 2021.
Article in English | WPRIM (Western Pacific) | ID: wpr-888822

ABSTRACT

HYD-PEP06, an endostatin-modified polypeptide, has been shown to produce effective anti-colorectal carcinoma effects through inhibiting epithelial-mesenchymal transition (EMT). However, whether HYD-PEP06 has similar suppressive effect on hepatocellular carcinoma (HCC) remained unknown. In this study, HYD-PEP06 inhibited metastasis and EMT but not proliferation

11.
Plant Cell Environ ; 42(11): 3015-3026, 2019 11.
Article in English | MEDLINE | ID: mdl-31286514

ABSTRACT

Plants use RNA silencing as a strong defensive barrier against virus challenges, and viruses counteract this defence by using RNA silencing suppressors (RSSs). With the objective of identifying host factors helping either the plant or the virus in this interaction, we have performed a yeast two-hybrid screen using P1b, the RSS protein of the ipomovirus Cucumber vein yellowing virus (CVYV, family Potyviridae), as a bait. The C-8 sterol isomerase HYDRA1 (HYD1), an enzyme involved in isoprenoid biosynthesis and cell membrane biology, and required for RNA silencing, was isolated in this screen. The interaction between CVYV P1b and HYD1 was confirmed in planta by Bimolecular Fluorescence Complementation assays. We demonstrated that HYD1 negatively impacts the accumulation of CVYV P1b in an agroinfiltration assay. Moreover, expression of HYD1 inhibited the infection of the potyvirus Plum pox virus, especially when antiviral RNA silencing was boosted by high temperature or by coexpression of homologous sequences. Our results reinforce previous evidence highlighting the relevance of particular composition and structure of cellular membranes for RNA silencing and viral infection. We report a new interaction of an RSS protein from the Potyviridae family with a member of the isoprenoid biosynthetic pathway.


Subject(s)
Arabidopsis/enzymology , Capsid Proteins/metabolism , Oxidoreductases/metabolism , Plum Pox Virus/metabolism , RNA Interference , Steroid Isomerases/metabolism , Arabidopsis/genetics , Arabidopsis/metabolism , Gene Expression , Green Fluorescent Proteins , Mutation , Oxidoreductases/genetics , Plant Diseases/virology , Plant Leaves/metabolism , Plant Leaves/virology , Plum Pox Virus/genetics , Plum Pox Virus/pathogenicity , Protein Binding , Steroid Isomerases/genetics , Temperature , Nicotiana/metabolism , Nicotiana/virology , Two-Hybrid System Techniques , Up-Regulation
12.
Gene ; 706: 84-90, 2019 Jul 20.
Article in English | MEDLINE | ID: mdl-31028867

ABSTRACT

Flammulina filiformis is an edible fungus that is largely cultivated and widely consumed around the world. The quantity and quality of the primordia, which gives rise to the fruiting body, affects its production efficiency. Hydrophobins are involved in the formation of the fruiting body of macrofungi. However, functional verification of the hydrophobin genes is limited to date. In this study, we used gene silencing and overexpression analyses to investigate the function of one F. filiformis hydrophobin gene (Hyd9) during the development of the fruiting body. The Hyd9-silenced transformants exhibited sparse aerial hyphae, resulting in fewer primordia and fruiting bodies. In contrast, the Hyd9 overexpression strain displayed denser aerial hyphae and more primordia. The phenotypes of these transgenic lines strongly suggested that Hyd9 plays an important role in the formation of aerial hyphal knots (the primary stage of primordia) and primordia in F. filiformis. These results will be beneficial for developing more efficient methods to induce primordia formation in F. filiformis and other commercially valuable mushrooms.


Subject(s)
Flammulina/genetics , Gene Expression Regulation, Fungal/genetics , Hyphae/genetics , Fruiting Bodies, Fungal/genetics , Fungal Proteins/genetics , Genes, Fungal/genetics , Hydrophobic and Hydrophilic Interactions
13.
Biotechnol Biofuels ; 10: 80, 2017.
Article in English | MEDLINE | ID: mdl-28360938

ABSTRACT

BACKGROUND: Citrobacter amalonaticus Y19 is a good biocatalyst for production of hydrogen (H2) from oxidation of carbon monoxide (CO) via the so-called water-gas-shift reaction (WGSR). It has a high H2-production activity (23.83 mmol H2 g-1 cell h-1) from CO, and can grow well to a high density on various sugars. However, its H2-production activity is expressed only when CO is present as an inducer and in the absence of glucose. RESULTS: In order to avoid dependency on CO and glucose, in the present study, the native CO-inducible promoters of WGSR operons (CO dehydrogenase, CODH, and CODH-dependent hydrogenase, CO-hyd) in Y19 were carefully analyzed and replaced with strong and constitutive promoters screened from Y19. One engineered strain (Y19-PR1), selected from three positive ones after screening ~10,000 colonies, showed a similar CO-dependent H2-production activity to that of wild-type Y19, without being affected by glucose and/or CO. Compared with wild-type Y19, transcription of the CODH operon in Y19-PR1 increased 1.5-fold, although that of the CO-hyd operon remained at a similar level. To enhance the activity of CO-Hyd in Y19-PR1, further modifications, including an increase in gene copy number and engineering of the 5' untranslated region, were attempted, but without success. CONCLUSIONS: Convenient recombinant Y19-PR1 that expresses CO-dependent H2-production activity without being limited by CO and glucose was obtained.

14.
Pain Med ; 18(7): 1278-1291, 2017 Jul 01.
Article in English | MEDLINE | ID: mdl-27651514

ABSTRACT

OBJECTIVES: A once-daily, extended-release hydrocodone bitartrate tablet with abuse-deterrent properties (Hysingla ER [HYD]) is available for the treatment of chronic pain in appropriate patients. This study evaluated the oral abuse potential and pharmacokinetics (PK) of HYD intact, chewed, or milled to fine particles in comparison with hydrocodone solution or placebo. DESIGN: Single-center, double-blind, randomized, five-period, five-treatment crossover study. SUBJECTS: Healthy adult, nondependent, recreational opioid users. METHODS: Forty subjects received orally administered treatments of hydrocodone 60 mg solution, HYD 60 mg intact, HYD 60 mg chewed, HYD 60 mg milled to fine particles, or placebo, separated by a five- to seven-day washout. Assessments over 36 hours postdose included subjective measures of drug liking and willingness to take drug again (assessed using visual analog scales [VAS]), pupillometry, PK, and safety measures. RESULTS: Following oral administration, HYD intact, HYD chewed, and HYD fine particles led to significantly lower "at this moment" drug liking compared with hydrocodone solution. HYD intact and chewed were significantly different from hydrocodone solution on overall drug liking, take drug again, and good effects. Pupil constriction, as measured by pupillometry, occurred later with HYD intact and HYD chewed than with hydrocodone solution. Across treatments (hydrocodone solution, HYD fine particles, HYD chewed, and HYD intact, respectively), mean C max and rate of absorption (C max /T max ) values decreased, respectively, and median T max values increased, respectively. Safety was consistent with the known effects of opioid agonists. CONCLUSION: HYD demonstrated reduced oral abuse potential compared with hydrocodone solution in healthy adult, nondependent, recreational opioid users.


Subject(s)
Analgesics, Opioid/administration & dosage , Analgesics, Opioid/pharmacokinetics , Hydrocodone/administration & dosage , Hydrocodone/pharmacokinetics , Opioid-Related Disorders/metabolism , Administration, Oral , Adult , Cross-Over Studies , Delayed-Action Preparations/administration & dosage , Delayed-Action Preparations/pharmacokinetics , Double-Blind Method , Drug Administration Schedule , Drug Compounding , Female , Humans , Male , Mastication/physiology , Middle Aged , Opioid-Related Disorders/drug therapy , Young Adult
15.
Pain Med ; 17(5): 820-31, 2016 05.
Article in English | MEDLINE | ID: mdl-26814240

ABSTRACT

OBJECTIVES: A once-daily, extended-release hydrocodone bitartrate tablet with abuse-deterrent properties (Hysingla ER® [HYD]) is available for the treatment of chronic pain in appropriate patients. This study evaluated the intranasal abuse potential and pharmacokinetics of HYD coarse and fine particles vs hydrocodone powder or placebo. DESIGN: Single-center, double-blind, positive- and placebo-controlled, randomized, four-treatment crossover study. SUBJECTS: Healthy adult, nondependent, recreational opioid users with a history of intranasal abuse. METHODS: During four treatment periods, subjects (N = 31) received hydrocodone powder 60 mg, HYD coarse particles 60 mg, HYD fine particles 60 mg, or placebo, with five-to-seven-day washouts between treatments. Measures over 36 hours postdose included drug-liking and willingness to take drug again, assessed using visual analog scales (VASs), pupillometry, intranasal irritation, and pharmacokinetics. RESULTS: Insufflation of both HYD coarse and fine particles led to lower "At this Moment" Drug Liking VAS peak values compared with hydrocodone powder, but higher values compared with placebo (P < 0.001 for all comparisons). Similar results were observed for Overall Drug Liking VAS, Take Drug Again VAS, and Subjective Drug Value. Compared with hydrocodone, insufflation of HYD particles led to reduced miosis and increased nasal irritation. Mean hydrocodone Cmax following insufflation of HYD coarse particles, HYD fine particles, and hydrocodone powder was 27.5, 36.5, and 105.8 ng/mL, respectively; median Tmax was ≥2-fold longer with either HYD particle size than hydrocodone powder; and (Cmax/Tmax) was 9.5, 13.4, and 82.0 ng/mL/h, respectively. Safety was consistent with that of opioid agonists. CONCLUSIONS: HYD demonstrated reduced intranasal abuse potential compared with hydrocodone powder.


Subject(s)
Analgesics, Opioid/administration & dosage , Analgesics, Opioid/pharmacokinetics , Hydrocodone/administration & dosage , Hydrocodone/pharmacokinetics , Illicit Drugs/pharmacokinetics , Opioid-Related Disorders/metabolism , Administration, Intranasal , Adult , Cross-Over Studies , Delayed-Action Preparations/administration & dosage , Delayed-Action Preparations/pharmacokinetics , Double-Blind Method , Drug Administration Schedule , Female , Humans , Male , Middle Aged , Opioid-Related Disorders/diagnosis , Powders , Young Adult
16.
J Biotechnol ; 211: 79-80, 2015 Oct 10.
Article in English | MEDLINE | ID: mdl-26210290

ABSTRACT

We report here the complete genome sequence of Citrobacter amalonaticus Y19 isolated from an anaerobic digester. PacBio single-molecule real-time (SMRT) sequencing was employed, resulting in a single scaffold of 5.58Mb. The sequence of a mega plasmid of 291Kb size is also presented.


Subject(s)
Carbon Monoxide/metabolism , Citrobacter/genetics , Citrobacter/metabolism , Genome, Bacterial , Base Sequence , Oxidation-Reduction , Sequence Analysis, DNA
17.
MAbs ; 7(1): 212-30, 2015.
Article in English | MEDLINE | ID: mdl-25559441

ABSTRACT

High viscosity of monoclonal antibody formulations at concentrations ≥100 mg/mL can impede their development as products suitable for subcutaneous delivery. The effects of hydrophobic and electrostatic intermolecular interactions on the solution behavior of MAB 1, which becomes unacceptably viscous at high concentrations, was studied by testing 5 single point mutants. The mutations were designed to reduce viscosity by disrupting either an aggregation prone region (APR), which also participates in 2 hydrophobic surface patches, or a negatively charged surface patch in the variable region. The disruption of an APR that lies at the interface of light and heavy chain variable domains, VH and VL, via L45K mutation destabilized MAB 1 and abolished antigen binding. However, mutation at the preceding residue (V44K), which also lies in the same APR, increased apparent solubility and reduced viscosity of MAB 1 without sacrificing antigen binding or thermal stability. Neutralizing the negatively charged surface patch (E59Y) also increased apparent solubility and reduced viscosity of MAB 1, but charge reversal at the same position (E59K/R) caused destabilization, decreased solubility and led to difficulties in sample manipulation that precluded their viscosity measurements at high concentrations. Both V44K and E59Y mutations showed similar increase in apparent solubility. However, the viscosity profile of E59Y was considerably better than that of the V44K, providing evidence that inter-molecular interactions in MAB 1 are electrostatically driven. In conclusion, neutralizing negatively charged surface patches may be more beneficial toward reducing viscosity of highly concentrated antibody solutions than charge reversal or aggregation prone motif disruption.


Subject(s)
Amino Acid Substitution , Antibodies, Monoclonal/chemistry , Antibodies, Monoclonal/genetics , Point Mutation , Humans , Hydrophobic and Hydrophilic Interactions , Solubility , Static Electricity , Viscosity
18.
J Exp Bot ; 65(9): 2545-56, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24692648

ABSTRACT

Carotenoid content is a primary determinant of wheat nutritional value and affects its end-use quality. Wheat grains contain very low carotenoid levels and trace amounts of provitamin A content. In order to enrich the carotenoid content in wheat grains, the bacterial phytoene synthase gene (CrtB) and carotene desaturase gene (CrtI) were transformed into the common wheat cultivar Bobwhite. Expression of CrtB or CrtI alone slightly increased the carotenoid content in the grains of transgenic wheat, while co-expression of both genes resulted in a darker red/yellow grain phenotype, accompanied by a total carotenoid content increase of approximately 8-fold achieving 4.76 µg g(-1) of seed dry weight, a ß-carotene increase of 65-fold to 3.21 µg g(-1) of seed dry weight, and a provitamin A content (sum of α-carotene, ß-carotene, and ß-cryptoxanthin) increase of 76-fold to 3.82 µg g(-1) of seed dry weight. The high provitamin A content in the transgenic wheat was stably inherited over four generations. Quantitative PCR analysis revealed that enhancement of provitamin A content in transgenic wheat was also a result of the highly coordinated regulation of endogenous carotenoid biosynthetic genes, suggesting a metabolic feedback regulation in the wheat carotenoid biosynthetic pathway. These transgenic wheat lines are not only valuable for breeding wheat varieties with nutritional benefits for human health but also for understanding the mechanism regulating carotenoid biosynthesis in wheat endosperm.


Subject(s)
Bacterial Proteins/genetics , Carotenoids/biosynthesis , Cryptoxanthins/biosynthesis , Erwinia/enzymology , Plants, Genetically Modified/metabolism , Triticum/metabolism , beta Carotene/biosynthesis , Bacterial Proteins/metabolism , Biosynthetic Pathways , Carotenoids/analysis , Cryptoxanthins/analysis , Erwinia/genetics , Plants, Genetically Modified/chemistry , Plants, Genetically Modified/genetics , Seeds/chemistry , Seeds/genetics , Seeds/metabolism , Triticum/chemistry , Triticum/genetics , Vitamin A/analysis , Vitamin A/biosynthesis , beta Carotene/analysis
19.
Fungal Biol ; 118(4): 385-93, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24742833

ABSTRACT

Hydrophobins are small secreted proteins ubiquitously found in filamentous fungi. Some hydrophobins were shown to have functions in fungal development, while others lack known function. Class II hydrophobins from Fusarium graminearum and Fusarium culmorum are characterized by formation of low stability aggregates and their solubility in organic solvents. They are economically relevant to the brewing industry because they can induce beer gushing. Since cellular functions of Hyd5p's are still unknown, we analyzed the influence of FgHyd5p on growth and morphology of F. graminearum using FgΔhyd5 knock-out mutants expressing sGFP under the control of the hyd5 promoter and compared them with the performance of the parent wild type strain. Results demonstrate that FgHyd5p does not affect the colony and hyphal morphology. FgHyd5p affects the hydrophobicity of aerial mycelia but had no obvious function in penetration of hyphae through the water air interface. The hydrophobin affects the morphology of conidia, but not their fitness. Different sources of carbon and nitrogen as well as different pH have no effect on the expression of the hyd5 gene, which was demonstrated to be expressed upon growth of F. graminearum on hydrophobic surfaces.


Subject(s)
Fungal Proteins/metabolism , Fusarium/cytology , Fusarium/growth & development , Carbon/metabolism , Fungal Proteins/genetics , Fusarium/chemistry , Fusarium/genetics , Gene Deletion , Gene Expression Profiling , Hydrogen-Ion Concentration , Hydrophobic and Hydrophilic Interactions , Hyphae/chemistry , Hyphae/cytology , Hyphae/growth & development , Nitrogen/metabolism , Spores, Fungal/chemistry , Spores, Fungal/cytology , Spores, Fungal/growth & development
20.
Talanta ; 120: 274-82, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24468370

ABSTRACT

This work was dedicated to the development of a simple and direct multivariate UV spectrophotometric method for the simultaneous determination of three antiemetic drugs (ondansetron, dexamethasone and aprepitant) in a new organogel formulation developed for their simultaneous transdermal administration. This method that does not require separation of the drugs and sophisticated instrument will permit to control quality of this new transdermal form both during the optimization step and for a further routine control of this preparation at the pharmacy department of the hospital. Hence, a partial least squares regression model using the spectral data record from 260 to 288 nm and 5 components, has firstly been validated thanks to the evaluation of the REP% (under 7.9%) and secondly using an accuracy profile approach (acceptance limit of ±10%). Thereby, the method allows the quantitation of the drugs in the ranges (5-15 mg L(-1)), (4-8 mg L(-1)) and (20-50 mg L(-1)) for ondansetron, dexamethasone and aprepitant, respectively. An HPLC/UV reference method has also been developed. Optimal separation (2.52

Subject(s)
Antiemetics/analysis , Dexamethasone/analysis , Gels/chemistry , Morpholines/analysis , Ondansetron/analysis , Spectrophotometry, Ultraviolet/methods , Administration, Cutaneous , Antiemetics/administration & dosage , Aprepitant , Chromatography, High Pressure Liquid/methods , Dexamethasone/administration & dosage , Least-Squares Analysis , Limit of Detection , Morpholines/administration & dosage , Ondansetron/administration & dosage
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