scholarly journals Origins of stereoselectivity in evolved ketoreductases

2015 ◽  
Vol 112 (51) ◽  
pp. E7065-E7072 ◽  
Author(s):  
Elizabeth L. Noey ◽  
Nidhi Tibrewal ◽  
Gonzalo Jiménez-Osés ◽  
Sílvia Osuna ◽  
Jiyong Park ◽  
...  
Keyword(s):  
Conformational Changes ◽  
Large Scale ◽  
Kinetic Studies ◽  
Md Simulations ◽  
Binding Pocket ◽  
Scale Production ◽  
Large Scale Production ◽  
Conformational Preferences ◽  
Short Chain Alcohol ◽  
The Stability

Mutants of Lactobacillus kefir short-chain alcohol dehydrogenase, used here as ketoreductases (KREDs), enantioselectively reduce the pharmaceutically relevant substrates 3-thiacyclopentanone and 3-oxacyclopentanone. These substrates differ by only the heteroatom (S or O) in the ring, but the KRED mutants reduce them with different enantioselectivities. Kinetic studies show that these enzymes are more efficient with 3-thiacyclopentanone than with 3-oxacyclopentanone. X-ray crystal structures of apo- and NADP+-bound selected mutants show that the substrate-binding loop conformational preferences are modified by these mutations. Quantum mechanical calculations and molecular dynamics (MD) simulations are used to investigate the mechanism of reduction by the enzyme. We have developed an MD-based method for studying the diastereomeric transition state complexes and rationalize different enantiomeric ratios. This method, which probes the stability of the catalytic arrangement within the theozyme, shows a correlation between the relative fractions of catalytically competent poses for the enantiomeric reductions and the experimental enantiomeric ratio. Some mutations, such as A94F and Y190F, induce conformational changes in the active site that enlarge the small binding pocket, facilitating accommodation of the larger S atom in this region and enhancing S-selectivity with 3-thiacyclopentanone. In contrast, in the E145S mutant and the final variant evolved for large-scale production of the intermediate for the antibiotic sulopenem, R-selectivity is promoted by shrinking the small binding pocket, thereby destabilizing the pro-S orientation.

scholarly journals Call for papers on special issue “Perovskite photovoltaics and optoelectronic devices”

2020 ◽  
Vol 2 (1) ◽  
pp. 049-049
Keyword(s):  
Solar Cells ◽  
Large Scale ◽  
Perovskite Solar Cells ◽  
Optoelectronic Devices ◽  
Scale Production ◽  
Special Issue ◽  
Device Structure ◽  
Stability Performance ◽  
Large Scale Production ◽  
The Stability

Aim & Scope: Metal halide perovskitehave been regarded as promising classes of materials for photovoltaics and optoelectronic devices, owing to the unique characteristics, such as long charge carrier diffusion lengths, precise tunable bandgaps, high light absorption coefficients, and high defect tolerance. Research on perovskite in the fields including photovoltaics, light-emitting diodes, lasers, X-ray imaging, and photodetectors has been gaining increasingly interest over the past years. Up to now, the efficiency of perovskite solar cells has grown from 3.8% in single-junction solar cells in 2009 to more than 25%, catching up the efficiency level of commercial silicon cells. Up to now, the key issues of perovskite photovoltaics and optoelectronic devices have become the stability, performance and large-scale production. This requires optimization of the film morphology, interface, device structure and the fabrication process. A lot work has been done on this issue and has made remarkable progress. We kindly invite you to submit a manuscript(s) for this Special Issue. Full papers, communications, and reviews are all welcome.

Heterologous Expression, Characterization and Evolution Prediction of a Diaphorase From Geobacillus sp. Y4.1MC1

2021 ◽  
Author(s):  
Jinzhao Shang ◽  
Shuohao Yue ◽  
Fang Zeng ◽  
Yun Chen ◽  
Longgang Jia
Keyword(s):  
Large Scale ◽  
Ketone Bodies ◽  
Scale Production ◽  
Hydroxybutyric Acid ◽  
E Coli ◽  
Ph Values ◽  
Structure Changes ◽  
Large Scale Production ◽  
Expression Characterization ◽  
The Stability

Abstract β-hydroxybutyric acid is the most sensitive indicator in ketoacidosis detection, and accounts for nearly 78% of the ketone bodies. Diaphorase is commonly used to detect the β-hydroxybutyric acid in clinical diagnosis. However, the extraction of diaphorase from animal myocardium is complex and low-yield, which is not convenient for large-scale production. In this study, a diaphorase from Geobacillus sp. Y4.1MC1 was efficiently heterologous expressed and purified in E. coli a yield of 110 mg/L culture. The optimal temperature and pH of this recombinant diaphorase (rDIA) were 55 °C and 6.5, respectively. It was proved that rDIA was a dual acid- and thermo-stable enzyme, and which showed much more accurate detection of β-hydroxybutyric acid than the commercial enzyme. Additionally, we also investigated the molecular interaction of rDIA with the substrate, and the conformation transition in different pH values by using homology modeling and molecular dynamics (MD) simulation. The results showed that 141-161 domain of rDIA played important role in the structure changes and conformations transmission at different pH values. Moreover, it was predicted that F105W, F105R and M186R mutants were able to improve the binding affinity of rDIA, and A2Y, P35F, Q36D, N210L, F211Y mutants were benefit for the stability of rDIA.

scholarly journals EXPERIMENTAL STUDY OF LIPOSOMAL DOCETAXEL ANALYSIS OF DOCETAXEL INCORPORATION AND STABILITY

2017 ◽  
Vol 39 (2) ◽  
pp. 121-123 ◽  
Author(s):  
Y M Krasnopolsky ◽  
A S Dudnichenko
Keyword(s):  
Experimental Study ◽  
Large Scale ◽  
Phospholipid Composition ◽  
Free Form ◽  
Scale Production ◽  
Optimal Composition ◽  
Liposomal Form ◽  
Large Scale Production ◽  
The Stability ◽  
Nanosize Particle

Aim: The article presents the results of developing the composition and technology of obtaining the liposomal form of docetaxel. The effect of the phospholipid composition of the membrane, ionic strength, pH, temperature, cryoprotectant type, and other factors on the stability of liposomes and the docetaxel incorporation has been considered. Results: Reduction of toxicity of the liposomal form of docetaxel (LD50 — 137 ± 7.7 mg/kg) was found in comparison with its free form (LD50 — 101 ± 6.3 mg/kg). Preservation of nanosize particle after lyophilization has been shown. Conclusions: As a result of the studies, the optimal composition and technological scheme for obtaining liposomes containing docetaxel have been developed allowing large-scale production of docetaxel in liposomal form.

I. S. A. Baud. Forms of Production and Women's Labour: Gender Aspects of Industrialisation in India and Mexico. New Delhi: Sage Publications. 1992. 321 pp.Hardbound. Price: Indian Rs 295.00.

1993 ◽  
Vol 32 (1) ◽  
pp. 129-131
Author(s):  
Naureen Talha
Keyword(s):  
Large Scale ◽  
Indian Society ◽  
New Delhi ◽  
Scale Production ◽  
Female Labour ◽  
Self Employment ◽  
Commodity Production ◽  
Large Scale Production ◽  
Mexican Society ◽  
Small Production

The literature on female labour in Third World countries has become quite extensive. India, being comparatively more advanced industrially, and in view of its size and population, presents a pictures of multiplicity of problems which face the female labour market. However, the author has also included Mexico in this analytical study. It is interesting to see the characteristics of developing industrialisation in two different societies: the Indian society, which is conservative, and the Mexican society, which is progressive. In the first chapter of the book, the author explains that he is not concerned with the process of industrialisation and female labour employed at different levels of work, but that he is interested in forms of production and women's employment in large-scale production, petty commodity production, marginal small production, and self-employment in the informal sector. It is only by analysis of these forms that the picture of females having a lower status is understood in its social and political setting.

An Efficient and Improved Process for the Synthesis of Itopride Hydrochloride and Trimethobenzamide Hydrochloride

2018 ◽  
Vol 15 (4) ◽  
pp. 572-575 ◽  
Author(s):  
Ponnusamy Kannan ◽  
Samuel I.D. Presley ◽  
Pallikondaperumal Shanmugasundaram ◽  
Nagapillai Prakash ◽  
Deivanayagam Easwaramoorthy
Keyword(s):  
Large Scale ◽  
Hydroxylamine Hydrochloride ◽  
Scale Production ◽  
One Pot ◽  
Hydrochloride Salt ◽  
Environmental Friendly ◽  
Large Scale Production ◽  
Non Ulcer Dyspepsia ◽  
Itopride Hydrochloride ◽  
Yield And Purity

Aim and Objective: Itopride is a prokinetic agent used for treating conditions like non-ulcer dyspepsia. Itopride is administered as its hydrochloride salt. Trimethobenzamide is used for treating nausea and vomiting and administered as its hydrochloride salt. The aim is to develop a novel and environmental friendly method for large-scale production of itopride and trimethobenzamide. Materials and Methods: Itopride and trimethobenzamide can be prepared from a common intermediate 4- (dimethylaminoethoxy) benzyl amine. The intermediate is prepared from one pot synthesis using Phyrdroxybenzaldehye and zinc dust and further reaction of the intermediate with substituted methoxy benzoic acid along with boric acid and PEG gives itopride and trimethobenzamide. Results: The intermediate 4-(dimethylaminoethoxy) benzylamine is prepared by treating p-hydroxybenzaldehyde and 2-dimethylaminoethyl chloride. The aldehyde formed is treated with hydroxylamine hydrochloride. The intermediate is confirmed by NMR and the purity is analysed by HPLC. Conclusion: Both itopride and trimethobenzamide were successfully synthesized by this method. The developed method is environmental friendly, economical for large-scale production with good yield and purity.

scholarly journals Cyanobacteria—From the Oceans to the Potential Biotechnological and Biomedical Applications

Marine Drugs ◽  
2021 ◽  
Vol 19 (5) ◽  
pp. 241
Author(s):  
Shaden A. M. Khalifa ◽  
Eslam S. Shedid ◽  
Essa M. Saied ◽  
Amir Reza Jassbi ◽  
Fatemeh H. Jamebozorgi ◽  
...  
Keyword(s):  
Bioactive Compounds ◽  
Biomedical Applications ◽  
Large Scale ◽  
Biological Activities ◽  
Scale Production ◽  
Pharmacological Activities ◽  
Large Scale Production ◽  
Marine Products ◽  
Hiv 1 ◽  
Successful Phase

Cyanobacteria are photosynthetic prokaryotic organisms which represent a significant source of novel, bioactive, secondary metabolites, and they are also considered an abundant source of bioactive compounds/drugs, such as dolastatin, cryptophycin 1, curacin toyocamycin, phytoalexin, cyanovirin-N and phycocyanin. Some of these compounds have displayed promising results in successful Phase I, II, III and IV clinical trials. Additionally, the cyanobacterial compounds applied to medical research have demonstrated an exciting future with great potential to be developed into new medicines. Most of these compounds have exhibited strong pharmacological activities, including neurotoxicity, cytotoxicity and antiviral activity against HCMV, HSV-1, HHV-6 and HIV-1, so these metabolites could be promising candidates for COVID-19 treatment. Therefore, the effective large-scale production of natural marine products through synthesis is important for resolving the existing issues associated with chemical isolation, including small yields, and may be necessary to better investigate their biological activities. Herein, we highlight the total synthesized and stereochemical determinations of the cyanobacterial bioactive compounds. Furthermore, this review primarily focuses on the biotechnological applications of cyanobacteria, including applications as cosmetics, food supplements, and the nanobiotechnological applications of cyanobacterial bioactive compounds in potential medicinal applications for various human diseases are discussed.

scholarly journals A Review on Additive Manufacturing Possibilities for Electrical Machines

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1940
Author(s):  
Muhammad Usman Naseer ◽  
Ants Kallaste ◽  
Bilal Asad ◽  
Toomas Vaimann ◽  
Anton Rassõlkin
Keyword(s):  
Additive Manufacturing ◽  
Large Scale ◽  
Three Dimensional ◽  
Electrical Machines ◽  
Electromagnetic Properties ◽  
Scale Production ◽  
Performance Parameters ◽  
Large Scale Production ◽  
One Step ◽  
Manufacturing Techniques

This paper presents current research trends and prospects of utilizing additive manufacturing (AM) techniques to manufacture electrical machines. Modern-day machine applications require extraordinary performance parameters such as high power-density, integrated functionalities, improved thermal, mechanical & electromagnetic properties. AM offers a higher degree of design flexibility to achieve these performance parameters, which is impossible to realize through conventional manufacturing techniques. AM has a lot to offer in every aspect of machine fabrication, such that from size/weight reduction to the realization of complex geometric designs. However, some practical limitations of existing AM techniques restrict their utilization in large scale production industry. The introduction of three-dimensional asymmetry in machine design is an aspect that can be exploited most with the prevalent level of research in AM. In order to take one step further towards the enablement of large-scale production of AM-built electrical machines, this paper also discusses some machine types which can best utilize existing developments in the field of AM.

scholarly journals Stabilized Hydroxide-Mediated Nickel-Based Electrocatalysts for High-Current-Density Hydrogen Evolution in Alkaline Media

2021 ◽  
Author(s):  
Yuting Luo ◽  
Zhiyuan Zhang ◽  
Fengning Yang ◽  
Jiong Li ◽  
Zhibo Liu ◽  
...  
Keyword(s):  
Water Splitting ◽  
Large Scale ◽  
Fossil Fuels ◽  
High Current Density ◽  
Critical Energy ◽  
Alkaline Media ◽  
Scale Production ◽  
High Current ◽  
Large Scale Production ◽  
Electrochemical Water Splitting

Large-scale production of green hydrogen by electrochemical water splitting is considered as a promising technology to address critical energy challenges caused by the extensive use of fossil fuels. Although nonprecious...

scholarly journals Xylanolytic Bacillus species for xylooligosaccharides production: a critical review

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Rozina Rashid ◽  
Muhammad Sohail
Keyword(s):  
Large Scale ◽  
Extracellular Enzymes ◽  
Membrane Separation ◽  
Well Being ◽  
Bacillus Species ◽  
Scale Production ◽  
Food Ingredients ◽  
Large Scale Production ◽  
Wide Range ◽  
Biological Impacts

AbstractThe capacity of different Bacillus species to produce large amounts of extracellular enzymes and ability to ferment various substrates at a wide range of pH and temperature has placed them among the most promising hosts for the industrial production of many improved and novel products. The global interest in prebiotics, for example, xylooligosaccharides (XOs) is ever increasing, rousing the quest for various forms with expanded productivity. This article provides an overview of xylanase producing bacilli, with more emphasis on their capacity to be used in the production of the XOs, followed by the purification strategies, characteristics and application of XOs from bacilli. The large-scale production of XOs is carried out from a number of xylan-rich lignocellulosic materials by chemical or enzymatic hydrolysis followed by purification through chromatography, vacuum evaporation, solvent extraction or membrane separation methods. Utilization of XOs in the production of functional products as food ingredients brings well-being to individuals by improving defense system and eliminating pathogens. In addition to the effects related to health, a variety of other biological impacts have also been discussed.

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