Publications by authors named "Leila Hassani"

Overproduction of desired native or nonnative biochemical(s) in (micro)organisms can be achieved through metabolic engineering. Appropriate rewiring of cell metabolism is performed by making rational changes such as insertion, up-/down-regulation and knockout of genes and consequently metabolic reactions. Finding appropriate targets (including proper sets of reactions to be knocked out) for metabolic engineering to design optimal production strains has been the goal of a number of computational algorithms.

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Many proteins and peptides can aggregate into amyloid fibrils with high-ordered and cross-β rich structure characteristics. Amyloid deposition is a common feature of neurodegenerative diseases called amyloidosis. Various natural polyphenolic compounds such as curcumin exhibited antiamyloidogenic activities, but less researches were focused on the metal complexes of these compounds.

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Overproduction of desired native or nonnative biochemical(s) in (micro)organisms can be achieved through metabolic engineering. Appropriate rewiring of cell metabolism is performed making rational changes such as insertion, up-/down-regulation and knockout of genes and consequently metabolic reactions. Finding appropriate targets (including proper sets of reactions to be knocked out) for metabolic engineering to design optimal production strains has been the goal of a number of computational algorithms.

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HIV-1 transactivator of transcription protein is one of the most promising AIDS vaccine candidates and plays central roles in the virus life cycle and pathogenesis. Understanding structural properties of vaccine candidate antigens leads to rational design of vaccines which improves their presentation to immune system and facilitates their manufacturing and storage. This study aims to investigate structural properties and stability of one variant of HIV-1 Tat recombinant protein using different spectroscopic, electrophoretic, and microscopic methods.

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Cyclomaltodextrinase (CDase) is a member of the alpha-amylase family GH13, the subfamily GH13_20. In addition to CDase and neopullulanase, this subfamily also contains maltogenic amylase. They have common structural features, but different substrate specificity.

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Background: Chronic use of renin-angiotensin system (RAS) antagonists (angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor antagonists (ARAS)) can cause hypotension during anesthesia. In some studies hemodynamic instability, including hypotension and its effects on the clinical outcome in patients treated with these drugs during coronary artery bypass graft (CABG) and need to excessive vasoactive drugs in these patient population, has been described. The aim of this study was to evaluate the effect of chronic consumption of ACEIs and ARAS on blood pressure and inotrope consumption during coronary artery bypass graft under cardiopulmonary bypass.

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Renilla Luciferase is a bioluminescent enzyme which is broadly implemented as protein reporter in biology-related researches. In this study, new evidences on the kinetics, structure, and dynamics of Renilla luciferase solvated in binary mixtures of glycerol and water using MD simulation along with experimental procedures including fluorescence and CD spectroscopy were obtained. The results indicated that the Renilla luciferase activity decreased at 0.

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Nature uses a Mn oxide-based catalyst for water oxidation in plants, algae, and cyanobacteria. Mn oxides are among major candidates to be used as water-oxidizing catalysts. Herein, we used two straightforward and promising methods to form Escherichia coli bacteria/Mn oxide compounds.

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Amyloid deposition, arising from the fibrillogenesis of proteins in organs and tissues of the body, causes several neurodegenerative disorders. One therapeutic approach is based on the use of polyphenols and their derivatives for suppressing and inhibiting the accumulation of these toxic fibrils in tissues. In the present study, the anti-amyloidogenic activities of bisdemethoxycurcumin (BDMC), a natural polyphenolic compound, and diacetylbisdemethoxycurcumin (DABC), a synthetic derivative of curcumin, on the amyloid fibrillation of hen egg white lysozyme (HEWL) is studied in depth using thioflavin T (ThT) fluorescence, atomic force microscopy (AFM), circular dichroism spectroscopy (CD), molecular docking and Ligplot calculations.

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Encysted embryos of Artemia are among the most stress-resistant eukaryotes partly due to the massive amount of a cysteine-rich protein termed artemin. High number of cysteine residues in artemin and their intramolecular spatial positions motivated us to investigate the role of the cysteine residues in the chaperone-like activity of artemin. According to the result of Ellman's assay, there are nine free thiols (seven buried and two exposed) and one disulfide bond per monomer of artemin.

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Antibacterial peptides have potential as novel therapeutic agents for bacterial infections. Aurein 1.2 is one of the smallest antibacterial peptides extracted from an anuran.

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A DNA enzyme with peroxidase activity is a G-quadruplex-based DNAzyme formed by hemin and G-quadruplex DNA. Activity of peroxide DNAzymes can be influenced by the structure of quadruplex DNA. In this investigation, the interaction of hemin with T30695 G-quadruplex DNA is evaluated.

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Curcumin has multiple pharmacological effects, but it has poor stability. Complexation of curcumin with metals improves its stability. Here, the effects of vanadyl curcumin and vanadyl diacetylcurcumin on the function and structure of horseradish peroxidase enzyme were evaluated by spectroscopic techniques.

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c-MYC DNA is an attractive target for drug design, especially for cancer chemotherapy. Around 90% of c-MYC transcription is controlled by NHE III1, whose 27-nt purine-rich strand has the ability to form G-quadruplex structure. In this investigation, interaction of ActD with 27-nt G-rich strand (G/c-MYC) and its equimolar mixture with the complementary sequence, (GC/c-MYC) as well as related C-rich oligonucleotide (C/c-MYC) was evaluated.

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β-lactoglobulin (BLG), the major bovine whey protein, is a well-characterized globular protein. It is a model protein for studying the structural transition and aggregation. BLG unfolds and aggregates through chemical and physical processes.

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Curcumin has a wide spectrum of biological and pharmacological activities including anti-inflammatory, antioxidant, antiproliferative, antimicrobial and anticancer activities. Complexation of curcumin with metals has gained attention in recent years for improvement of its stability. In this study, the effect of gallium curcumin and gallium diacetylcurcumin on the structure, function and oxidative stability of horseradish peroxidase (HRP) enzyme were evaluated by spectroscopic techniques.

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The aim of this work was to develop a novel formulation method, termed modified-PGSS (modified-Particle from Gas Saturated Solution), for the encapsulation of protein into polymeric microparticles in CO medium. In this study, isosorbide dimethyl ether (DMI), a non-toxic water-miscible solvent, was used for the formulation and lysozyme was chosen as a model protein for encapsulation into PLGA microparticles. First, the mechanism of particle formation has been extensively studied and was discussed in detail.

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The c-MYC gene plays an important role in the regulation of cell proliferation and growth and it is overexpressed in a wide variety of human cancers. Around 90% of c-MYC transcription is controlled by the nuclease-hypersensitive element III1 (NHE III1), whose 27-nt purine-rich strand has the ability to form a G-quadruplex structure under physiological conditions. Therefore, c-MYC DNA is an attractive target for drug design, especially for cancer chemotherapy.

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Biotechnology is consistently seeking improved enzyme stability. Enzymes have great properties, although their marginal stability limits their applications. Among the strategies for improving stability of the enzymes, chemical modification is a simple and effective technique.

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The G-quadruplex DNA is a novel target for anticancer drug discovery and many scientific groups are investigating interaction of small molecules with G-quadruplex DNA to discover therapeutic agents for cancer. Here, interaction of a phthalocyanine (Cu(PcTs)) and two tetrapyridinoporphyrazines ([Cu(2,3-tmtppa)](4+) and [Cu(3,4-tmtppa)](4+)) with Na(+) and K(+) forms of human telomeric G-quadruplex DNA has been investigated by spectroscopic techniques. The results indicated that interaction of the cationic porphyrazines is remarkably stronger than the anionic phthalocyanine and they presumably bind to the G-quadruplex DNA through end-stacking.

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The aim of the present work was to assess the merits of supercritical CO (SC-CO) as a process for protein encapsulation into calcium carbonate microparticles. Lysozyme, chosen as a model protein, was entrapped during CaCO precipitation in two different media: water (normal route) and SC-CO. The particles were characterized and compared in terms of size, zeta potential, morphology by SEM, crystal polymorph and lysozyme encapsulation.

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Encysted embryos of Artemia are exceptionally resistant to severe environmental stress. This resistance is thought to depend in part on the existence of a protein termed artemin. There is only little information about the function of artemin.

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Multi-color bioluminescence is developed using the introduction of single/double disulfide bridges in firefly luciferase. The bioluminescence reaction, which uses luciferin, Mg(2+)-ATP and molecular oxygen to yield an electronically excited oxyluciferin, is carried out by the luciferase and emits visible light. The bioluminescence color of firefly luciferases is determined by the luciferase sequence and assay conditions.

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The stability of enzymes remains a critical issue in biotechnology. Compared with the strategies for obtaining stable enzymes, chemical modification is a simple and effective technique. In the present study, chemical modification of horseradish peroxidase (HRP) was carried out with pyromellitic anhydride.

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