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关键词： Functionalized MWCNT   Mixed-matrix membrane   Surface waters   BOD   COD  

摘要： In this work, a mixed-matrix (MM) membrane consisting of functionalized multi-walled carbon nanotube (MWCNT), polyethersulfone (PES) and polyester non-woven fabric was fabricated using immersion precipitation. The membrane capability in reducing the biochemical oxygen demand (BOD) and chemical oxygen demand (COD) levels of the surface water samples collected from rural areas in Sarawak, Malaysia are tested. MWCNTs were functionalized using chemical oxidation to promote functional group onto their sidewalls. Raman analysis reveals a higher peak in D-band than G-band in the functionalized CNT but the higher I-D/I-G intensity ratio was demonstrated by CNT treated with strong acid. Surface morphological characterization verified the existence of the defects in CNT structures, which was reflected on the sidewall defects, debundling and shortening of the MWCNTs. Meanwhile, the surface waters were tested for BOD and COD levels and treated with three different types of membrane by conventional vacuum filtration. Membrane of raw MM displayed the best treatment capability which is reflected on its ability to maintain the BOD level and reduce the COD level with a consistent percentage. Thus, this work provides a different insight in membrane capability in treating BOD and COD levels in surface waters.

关键词： Trichoderma virens   GAPDH   Protein purification   Koningic acid   Secondary metabolism  

摘要： Trichoderma virens genome harbors two isoforms of GAPDH, one (gGPD) involved in glycolysis and the other one (vGPD) in secondary metabolism. vGPD is expressed as part of the "vir" cluster responsible for the biosynthesis of volatile sesquiterpenes. The secondary metabolism-associated GAPDH is tolerant to the anti-cancer metabolite heptelidic acid (HA), produced by T. virens. Characterizing the HA-tolerant form of GAPDH, thus has implications in cancer therapy. In order to get insight into the mechanism of HA-tolerance of vGPD, we have purified recombinant form of this protein. The protein displays biochemical and biophysical characteristics analogous to the gGPD isoform. It exists as a tetramer with Tm of about 56.5 degrees C, and displays phosphorylation enzyme activity with Km and Kcat of 0.38 mM and 2.55 sec(-1), respectively. The protein weakly binds to the sequence upstream of the vir4 gene that codes for the core enzyme (a terpene cyclase) of the "vir" cluster. The EMSA analysis indicates that vGPD may not act as a transcription factor driving the "vir" cluster, at least not by directly binding to the promoter region. We also succeeded in obtaining small crystals of this protein. We have constructed structural models of vGPD and gGPD of T. virens. In silico constrained docking analysis reveals weaker binding of heptelidic acid in vGPD, compared to gGPD protein.

关键词： Propionic acidemia   Treatment   Biomarker   Phenotype  

摘要： Propionic acidemia (PA) is caused by inherited deficiency of mitochondrial propionyl-CoA carboxylase (PCC) and results in significant neurodevelopmental and cardiac morbidity. However, relationships among therapeutic intervention, biochemical markers, and disease progression are poorly understood. Sixteen individuals homozygous for PCCB c.1606A > G (***536Asp) variant PA participated in a two-week suspension of therapy. Standard metabolic markers (plasma amino acids, blood spot methylcitrate, plasma/urine acylcarnitines, urine organic acids) were obtained before and after stopping treatment. These same markers were obtained in sixteen unaffected siblings. Echocardiography and electrocardiography were obtained from all subjects. We characterized the baseline biochemical phenotype of untreated PCCB c.1606A > G homozygotes and impact of treatment on PCC deficiency biomarkers. Therapeutic regimens varied widely. Suspension of therapy did not significantly alter branched chain amino acid levels, their alpha-ketoacid derivatives, or urine ketones. Carnitine supplementation significantly increased urine propionylcarnitine and its ratio to total carnitine. Methylcitrate blood spot and urine levels did not correlate with other biochemical measures or cardiac outcomes. Treatment of PCCB c.1606A > G homozygotes with protein restriction, prescription formula, and/or various dietary supplements has a limited effect on core biomarkers of PCC deficiency. These patients require further longitudinal study with standardized approaches to better understand the relationship between biomarkers and disease burden.

关键词： Palm oil   Fatty acids   Tocopherols   Tocotrienols   Carotenoids   Polyphenols   Sustainability  

摘要： Palm oil (PO), although subject of controversies, is the most consumed oil and the first source of oil widely produced. In this review, we discussed its biochemical composition in fatty acids, carotenoids, vitamin E, its phenolic compounds, and its nutritional benefits. We addressed its biochemical properties in relation with the stereospecific distribution of its unsaturated fatty acids at the sn-2 position in triacylglycerols. PO is one of the most stable oils, which help it prolong food storability mostly due not only to its content of saturated fatty acids, but also to its antioxidant compounds. PO plays an important role in the prevention of many pathologies (diabetes, cardiovascular diseases, obesity and cancers). It is widely use in nutrition especially in the food industry and in biodiesel industry. Faced with attacks from environmentalists who blame PO for destorying biodiversity, there is an urgent need to develop a sustainable PO production plan. Compliance with sustainable PO goals would help ease those controversies. The use and consumption of PO in normal or moderate amounts in a varied, balanced and adequate diet does not present any known health risk. Education campaigns on the nutritional benefits of PO should be promoted. (C) 2020 Elsevier B.V. and Societe Francaise de Biochimie et Biologie Moleculaire (SFBBM). All rights reserved.

关键词： ClpB   Disaggregase   Chloroplasts   Arabidopsis thaliana   ATPase   Chaperone  

摘要： Key message The first biochemical characterization of a chloroplastic disaggregase is reported (Arabidopsis thalianaClpB3). ClpB3 oligomerizes into active hexamers that resolubilize aggregated substrates using ATP and without the aid of partners. Disaggregases from the Hsp100/Clp family are a type of molecular chaperones involved in disassembling protein aggregates. Plant cells are uniquely endowed with ClpB proteins in the cytosol, mitochondria and chloroplasts. Chloroplastic ClpB proteins have been implicated in key processes like the unfolded protein response;however, they have not been studied in detail. In this study, we explored the biochemical properties of a chloroplastic ClpB disaggregase, in particular, ClpB3 ***. ClpB3 was produced recombinantly inEscherichia coliand affinity-purified to near homogeneity. ClpB3 forms a hexameric complex in the presence of MgATP and displays intrinsic ATPase activity. We demonstrate that ClpB3 has ATPase activity in a wide range of pH and temperature values and is particularly resistant to heat. ClpB3 specifically targets unstructured polypeptides and mediates the reactivation of heat-denatured model substrates without the aid of the Hsp70 system. Overall, this work represents the first in-depth biochemical description of a ClpB protein from plants and strongly supports its role as the putative disaggregase chaperone in chloroplasts.

关键词： Brassica napus   Brassica oleracea   Brassica rapa   CO(2)response   crop improvement   dynamic photosynthesis   photosynthetic electron transport   photosynthetic induction   Rubisco   stomata  

摘要： Interventions to increase crop radiation use efficiency rely on understanding of how biochemical and stomatal limitations affect photosynthesis. When leaves transition from shade to high light, slow increases in maximum Rubisco carboxylation rate and stomatal conductance limit net CO(2)assimilation for several minutes. However, as stomata open intercellular [CO2] increases, so electron transport rate could also become limiting. Photosynthetic limitations were evaluated in three importantBrassicacrops:Brassica rapa,Brassica oleraceaandBrassica napus. Measurements of induction after a period of shade showed that net CO(2)assimilation byB. rapaandB. napussaturated by 10 min. A new method of analyzing limitations to induction by varying intercellular [CO2] showed this was due to co-limitation by Rubisco and electron transport. By contrast, inB. oleraceapersistent Rubisco limitation meant that CO(2)assimilation was still recovering 15 min after induction. Correspondingly,B. oleraceahad the lowest Rubisco total activity. The methodology developed, and its application here, shows a means to identify the basis of variation in photosynthetic efficiency in fluctuating light, which could be exploited in breeding and bioengineering to improve crop productivity.

关键词： Ammonia mitigation   Biotreatment   Poultry manure management   Anaerobic digestion   Biogas  

摘要： Poultry manure has great potential for renewable energy utilization in biogas production. However, extremely high levels of nitrogen lead to unstable conditions in the anaerobic process, including the accumulation of intermediates, such as ammonia, which reduces the biogas production and the quality of the biogas. For this reason, additional measures are needed to ensure the proper management of poultry manure in anaerobic systems. This study evaluated the effect of primary biological treatment of poultry manure on biochemical methane potential (CH4) and reduction of ammonia (NH3) emissions. The results obtained when evaluating the biochemical methane potential from the digestate revealed that the biological additives selected for the study did not significantly influence the biochemical methane potential. After considering the differences of dry organic matter, it was found that maintaining optimum conditions and using biological additives during pretreatment increases the biochemical methane potential from 11.00 to 89.94 L CH4/kg volatile solids (VS). Biological pretreatment of poultry manure has a positive effect on biogas composition: methane concentration increases by 6.3-10.4% after pretreatment, and impurities such as hydrogen sulphide (H2S) decrease by 1.1-17.4 times. Ammonia emissions from all treatments of poultry manure were higher than those from untreated poultry manure, as measured by the evaporation rate of NH3. However, when measuring the evaporation rate of NH3 from the digestate, it was found that NH3 emission rates showed similar trends.

关键词： Potato cultivar   Peel powder   Flesh powder   Resistant starch   Glycoalkaloid   Rheology  

摘要： Four different potato cultivars, namely, Kufri Chipsona 1 and Kufri Frysona (processing purpose), Kufri Jyoti and Kufri Bahar (table purpose) were converted into flesh and peel powder (raw and after boiling) and studied for their respective biochemical and functional attributes to get an idea of possible dynamics of their utilization in different food formulation as bioadditives. The 16 variants of powder obtained retained less than 10% moisture content and demonstrated 'very good' to 'fair' flowability. Peel powders recorded a higher total mineral, fiber, phenolic contents and total antioxidant activity than the flesh powders which were significantly affected by boiling. Among raw and boiled flesh powders, highest reducing and total sugars were recorded for Kufri Bahar while least was observed in Kufri Chipsona 1. Colour coordinate showed that boiling imparts brightness to flesh powder while peel powder got darkened. Boiling of the tubers resulted in an increase in the resistant starch (29% maximum) and flavour (180% maximum) component. Peel exhibited a total glycoalkaloid content in the range of 0.75 (Kufri Frysona) to 1.7 mg/100 g (Kufri Bahar) that is well within the acceptable limits. Rheological study of the flesh powders revealed a reduction of about 11-18 degrees C in pasting temperature and about 87-90% in peak viscosity, setback, breakdown value and final viscosity upon boiling. This study revealed that the traditional processing method such as boiling can significantly modify the techno-functional characteristics of potato flesh and peel powders which can further govern their end use in various food formulations.

关键词： Anesthetics   Ketamine   Etomidate   Cardiodynamics   Biochemical parameters   Hematological parameters   Oxidative stress   Rat  

摘要： It is well known the use of ketamine and etomidate in clinical practice;however, the difference in the systemic effects of these two anesthetic agents is still debatable. Thus, in the present study we aimed to compare their effects on heart, and other organs through estimation of cardiodynamics, biochemical and hematological parameters. Male Wistar rats were divided in 2 groups containing of 2 subgroups (n = 7 in each subgroup,n = 28 in total): (1) bolus injection of anesthetic ketamine (40 mg/kg b.w., i.p.n = 14);(2) bolus injection of anesthetic etomidate (20 mg/kg b.w., i.p.n = 14). The experiments were done in vitro in one subgroup of each group: cardiodynamic variables (dp/dt(max), dp/dt(min), heart rate), coronary flow, oxidative stress in coronary effluent and cardiac tissue homogenate, and in vivo in another subgroup: biochemical and hematological parameters, and oxidative stress in haemolysate. Significantly increased left ventricular contractility (dp/dt(max)) and relaxation (dp/dt(min)) were noticed in etomidate group. Creatinine (CREA), HDL cholesterol and folate were significantly higher in etomidate group, whereas amylase (AMY) and eosinophils in ketamine group. Our results suggested that ketamine has more antioxidant potential compared to etomidate, and etomidate has more favorable effects regarding cardiac performance.

关键词： Cancer   Immunotherapy   Checkpoint proteins  

摘要： Cancer is a group of diseases involving disordered growth of abnormal cells with the potential to invade and spread to other parts of the body. Today, immunotherapy is the most efficient treatment, with fewer side effects. Notably, the employment of monoclonal antibodies to inhibit checkpoint proteins, such as CTLA-4, has caused much excitement among cancer immunotherapy researchers. Thus, in-depth analysis through quantum biochemistry and molecular dynamics simulations was performed to understand the complex formed by ipilimumab and its target CTLA-4. Our computational results provide a better understanding of the binding mechanisms and new insights about the CTLA-4: ipilimumab interaction, identifying essential amino acid residues to support the complex. Additionally, we report new interactions such as aromatic-aromatic, aromatic-sulfur, and cation-pi interactions to stabilize the CTLA-4:ipilimumab complex. Finally, quantum biochemistry analyses reveal the most important amino acid residues involved in the CTLA-4:ipilimumab interface, which were used to design synthetic peptides to inhibit CTLA-4. The computational results presented here provide a better understanding of the CTLA-4:ipilimumab binding mechanisms, and can support the development of alternative antibody-based drugs with high relevance in cancer immunotherapy.y