scholarly journals Immobilization of laccase from Trametes versicolor on Lifetechtm supports for applications in degradation of industrial dyes

2020 ◽  
Vol 74 (3) ◽  
pp. 197-209
Author(s):  
Jelena Bebic ◽  
Katarina Banjanac ◽  
Marija Corovic ◽  
Ana Milivojevic ◽  
Milica Simovic ◽  
...  

In this study, immobilization of laccase from Trametes versicolor on eight Lifetech? supports, with different characteristics (pore size, length of the spacer arm and functional groups), was studied and optimized for intended use in bioremediation for decolorization of industrial wastewaters. Out of six tested amino-functionalized supports, the most promising carrier was proved to be porous Lifetech? ECR8309F with primary amino groups and a C2 spacer arm. Onto this support, laccase is attached by forming electrostatic interactions so that the most active preparation has shown the activity of 66876 U/g support. On the other hand, during immobilization of laccase on epoxy-functionalized Lifetech? ECR8285F, via hydrophobic interactions and covalent bonding confirmed by a desorption assay, immobilization yield of 60 % and the activity of 118929 U/g were accomplished. Furthermore, immobilized enzyme on this support showed high capacity for decolorization of dyes (Lanaset? Violet B, Lanaset? Blue 2R, bromothymol blue and bromocresol green), by combination of both adsorption and enzyme degradation. Decolorization was in the range of 88 to 96 % after 4 h, with more than 80 % achieved after only 45 min. Also, this preparation demonstrated high operational stability during seven consecutive reuses in all examined dye reaction systems.

2002 ◽  
Vol 68 (8) ◽  
pp. 3965-3968 ◽  
Author(s):  
Patricia A. Shields ◽  
Samuel R. Farrah

ABSTRACT Viruses were characterized by their adsorption to DEAE-Sepharose or by their elution from octyl-Sepharose by using buffered solutions of sodium chloride with different ionic strengths. Viruses whose adsorption to DEAE-Sepharose was reduced most rapidly by an increase in the sodium chloride concentration were considered to have the weakest electrostatic interactions with the solids; these viruses included MS2, E1, and φX174. Viruses whose adsorption to DEAE-Sepharose was reduced least rapidly were considered to have the strongest electrostatic interactions with the column; these viruses included P1, T4, T2, and E5. All of the viruses studied adsorbed to octyl-Sepharose in the presence of 4 M NaCl. Viruses that were eluted most rapidly following a decrease in the concentration of NaCl were considered to have the weakest hydrophobic interactions with the column; these viruses included φX174, CB4, and E1. Viruses that were eluted least rapidly from the columns after the NaCl concentration was decreased were considered to have the strongest hydrophobic interactions with the column; these viruses included f2, MS2, and E5.


2021 ◽  
Vol 9 ◽  
Author(s):  
Subhash Chander ◽  
Giriraj T. Kulkarni ◽  
Neerupma Dhiman ◽  
Harsha Kharkwal

Hydrogels possess a unique three-dimensional, cross-linked network of polymers capable of absorbing large amounts of water and biological fluids without dissolving. Nanohydrogels (NGs) or nanogels are composed of diverse types of polymers of synthetic or natural origin. Their combination is bound by a chemical covalent bond or is physically cross-linked with non-covalent bonds like electrostatic interactions, hydrophobic interactions, and hydrogen bonding. Its remarkable ability to absorb water or other fluids is mainly attributed to hydrophilic groups like hydroxyl, amide, and sulphate, etc. Natural biomolecules such as protein- or peptide-based nanohydrogels are an important category of hydrogels which possess high biocompatibility and metabolic degradability. The preparation of protein nanohydrogels and the subsequent encapsulation process generally involve use of environment friendly solvents and can be fabricated using different proteins, such as fibroins, albumin, collagen, elastin, gelatin, and lipoprotein, etc. involving emulsion, electrospray, and desolvation methods to name a few. Nanohydrogels are excellent biomaterials with broad applications in the areas of regenerative medicine, tissue engineering, and drug delivery due to certain advantages like biodegradability, biocompatibility, tunable mechanical strength, molecular binding abilities, and customizable responses to certain stimuli like ionic concentration, pH, and temperature. The present review aims to provide an insightful analysis of protein/peptide nanohydrogels including their preparation, biophysiochemical aspects, and applications in diverse disciplines like in drug delivery, immunotherapy, intracellular delivery, nutraceutical delivery, cell adhesion, and wound dressing. Naturally occurring structural proteins that are being explored in protein nanohydrogels, along with their unique properties, are also discussed briefly. Further, the review also covers the advantages, limitations, overview of clinical potential, toxicity aspects, stability issues, and future perspectives of protein nanohydrogels.


Pharmaceutics ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1143
Author(s):  
Julius Sundermann ◽  
Holger Zagst ◽  
Judith Kuntsche ◽  
Hermann Wätzig ◽  
Heike Bunjes

Bone morphogenetic protein 2 (BMP-2) has a high tendency to aggregate at physiological pH and physiological ionic strength, which can complicate the development of growth factor delivery systems. The aggregation behavior in differently concentrated BMP-2 solutions was investigated using dynamic and static light scattering. It was found that at higher concentrations larger aggregates are formed, whose size decreases again with increasing dilution. A solubilizing effect and therefore less aggregation was observed upon the addition of albumin. Imaged capillary isoelectric focusing and the simulation of the surface charges of BMP-2 were used to find a possible explanation for the unusually low solubility of BMP-2 at physiological pH. In addition to hydrophobic interactions, attractive electrostatic interactions might be decisive in the aggregation of BMP-2 due to the particular distribution of surface charges. These results help to better understand the solubility behavior of BMP-2 and thus support future pharmaceutical research and the development of new strategies for the augmentation of bone healing.


Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 285 ◽  
Author(s):  
Li Wang ◽  
Coucong Gong ◽  
Xinzhu Yuan ◽  
Gang Wei

Biomolecular self-assembly provides a facile way to synthesize functional nanomaterials. Due to the unique structure and functions of biomolecules, the created biological nanomaterials via biomolecular self-assembly have a wide range of applications, from materials science to biomedical engineering, tissue engineering, nanotechnology, and analytical science. In this review, we present recent advances in the synthesis of biological nanomaterials by controlling the biomolecular self-assembly from adjusting internal interactions and external stimulations. The self-assembly mechanisms of biomolecules (DNA, protein, peptide, virus, enzyme, metabolites, lipid, cholesterol, and others) related to various internal interactions, including hydrogen bonds, electrostatic interactions, hydrophobic interactions, π–π stacking, DNA base pairing, and ligand–receptor binding, are discussed by analyzing some recent studies. In addition, some strategies for promoting biomolecular self-assembly via external stimulations, such as adjusting the solution conditions (pH, temperature, ionic strength), adding organics, nanoparticles, or enzymes, and applying external light stimulation to the self-assembly systems, are demonstrated. We hope that this overview will be helpful for readers to understand the self-assembly mechanisms and strategies of biomolecules and to design and develop new biological nanostructures or nanomaterials for desired applications.


2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Ayman A. Gouda ◽  
Alaa S. Amin ◽  
Ragaa El-Sheikh ◽  
Amira G. Yousef

Simple, rapid, and extractive spectrophotometric methods were developed for the determination of some fluoroquinolones antibiotics: gemifloxacin mesylate (GMF), moxifloxacin hydrochloride (MXF), and enrofloxacin (ENF) in pure forms and pharmaceutical formulations. These methods are based on the formation of ion-pair complexes between the basic drugs and acid dyes, namely, bromocresol green (BCG), bromocresol purple (BCP), bromophenol blue (BPB), bromothymol blue (BTB), and methyl orange (MO) in acidic buffer solutions. The formed complexes were extracted with chloroform and measured at 420, 408, 416, 415, and 422 nm for BCG, BCP, BPB, BTB, and MO, respectively, for GMF; at 410, 415, 416, and 420 nm for BCP, BTB, BPB, and MO, respectively, for MXF; and at 419 and 414 nm for BCG and BTB, respectively, in case of ENF. The analytical parameters and their effects are investigated. Beer’s law was obeyed in the ranges 1.0–30, 1.0–20, and 2.0–24 μg mL−1for GMF, MXF, and ENF, respectively. The proposed methods have been applied successfully for the analysis of the studied drugs in pure forms and pharmaceutical formulations. Statistical comparison of the results with the reference methods showed excellent agreement and indicated no significant difference in accuracy and precision.


2013 ◽  
Vol 288 (23) ◽  
pp. 16905-16915 ◽  
Author(s):  
Angela M. Scott ◽  
Corina E. Antal ◽  
Alexandra C. Newton

The cellular activation of conventional protein kinase C (PKC) isozymes is initiated by the binding of their C2 domains to membranes in response to elevations in intracellular Ca2+. Following this C2 domain-mediated membrane recruitment, the C1 domain binds its membrane-embedded ligand diacylglycerol, resulting in activation of PKC. Here we explore the molecular mechanisms by which the C2 domain controls the initial step in the activation of PKC. Using stopped-flow fluorescence spectroscopy to measure association and dissociation rate constants, we show that hydrophobic interactions are the major driving force in the binding of the C2 domain to anionic membranes, whereas electrostatic interactions dominate in membrane retention. Specifically, mutation of select hydrophobic or select basic residues in the Ca2+-binding loops reduces membrane affinity by distinct mechanisms; mutation of hydrophobic residues primarily alters association rate constants, whereas mutation of charged residues affects dissociation rate constants. Live cell imaging reveals that introduction of these mutations into full-length PKCα not only reduces the Ca2+-dependent translocation to plasma membrane but, by impairing the plasma membrane-sensing role of the C2 domain, causes phorbol ester-triggered redistribution of PKCα to other membranes, such as the Golgi. These data underscore the key role of the C2 domain in driving conventional PKC isozymes to the plasma membrane and reveal that not only the amplitude but also the subcellular location of conventional PKC signaling can be tuned by altering the affinity of this module for membranes.


1979 ◽  
Vol 34 (10) ◽  
pp. 1225-1229
Author(s):  
B. Sesta ◽  
C. La Mesa ◽  
C. Cantale ◽  
M. Vincenzini

Abstract The density, viscosity and dielectric constant of aqueous proline and hydroxyproline solutions have been determined at 25 °C. The results appear to indicate that the two aminoacids have a destructive effect on the molecular water aggregates. The equivalent conductance of tetramethylammonium iodide and tetrabutylammonium iodide in aqueous proline and hydroxyproline solutions has been measured at 25°C. The aminoacids increase the viscosity of the solutions and decrease the limiting equivalent conductance of the two electrolytes. Electrostatic interactions of the iodide ions with the water molecules and hydrophobic interactions of the tetraalkylammonium ions with the aminoacids also seem to affect the conductometric behaviour of the electrolytes.


Toxins ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 771
Author(s):  
Alma Vázquez-Durán ◽  
María de Jesús Nava-Ramírez ◽  
Daniel Hernández-Patlán ◽  
Bruno Solís-Cruz ◽  
Víctor Hernández-Gómez ◽  
...  

Adsorption of the carcinogen aflatoxin B1 (AFB1) onto agro-waste-based materials is a promising alternative over conventional inorganic binders. In the current study, two unmodified adsorbents were eco-friendly prepared from kale and lettuce agro-wastes. A dynamic gastrointestinal tract-simulated model was utilized to evaluate the removal efficiency of the sorptive materials (0.5%, w/w) when added to an AFB1-contaminated diet (100 µg AFB1/kg). Different characterization methodologies were employed to understand the interaction mechanisms between the AFB1 molecule and the biosorbents. Based on adsorption results, the biosorbent prepared from kale was the best; its maximum adsorption capacity was 93.6%, which was significantly higher than that of the lettuce biosorbent (83.7%). Characterization results indicate that different mechanisms may act simultaneously during adsorption. Non-electrostatic (hydrophobic interactions, dipole-dipole interactions, and hydrogen bonding) and electrostatic interactions (ionic attractions) together with the formation of AFB1-chlorophyll complexes appear to be the major influencing factors driving AFB1 biosorption.


2020 ◽  
pp. 13-14
Author(s):  
O.G. Braginets ◽  
V.V. Ivasyk ◽  
B.O. Kondratskyi ◽  
D.L. Kachmaryk ◽  
V.L. Novak

Background. Aprotinin is a polypeptide, a proteinase inhibitor of natural origin. It inhibits kallikrein, kininogenase, plasmin, trypsin, chymotrypsin; blocks the activator of profibrinolysin, which helps to stop bleeding. Aprotinin is obtained from the lungs of cattle. Objective. To study the sorption of aprotinin on silochromic sorbents. Materials and methods. Affinity sorbents based on silochrome were used in the work: p-chlorobenzyl-silochrome, active bright blue K-silochrome, aminopropyl silochrome, phenyl-diol-silochrome, phenyl-glutaryl-silochrome. The optical density was measured on KFK-3 (590 nm, 750 nm) and SF-46 (280 nm). An NP-3 peristaltic pump was used for chromatographic purification. Results and discussion. Based on the obtained data, it can be assumed that the mechanism of binding of aprotinin to all carriers is obviously the same and is based on the presence of hydrophobic sites in its molecule, which leads to hydrophobic interactions with sorbents. However, increasing the hydrophobicity of the eluent does not lead to desorption of the inhibitor. Obviously, in addition to hydrophobic, a significant role is played by the electrostatic interaction, which is eliminated by increasing the ionic strength. The sorbents under study have a high capacity, they do not change their volume when the ionic strength or hydrophobicity changes, and therefore may be suitable for large-scale applications. Conclusions. Affinity sorbents based on silochrome, containing as ligands aminobenzene, p-chlorobenzyl chloride and active chlorotriazine dye of the anthraquinone series “active bright blue K”, in contrast to the original matrix – silochrome aminopropyl water and effectively dissolve. Increasing the ionic strength or hydrophobicity of desorbing solutions does not lead to elution of aprotinin due to additional electrostatic interaction. Therefore, the desorption of aprotinin is achieved only if it is eliminated in the presence of 25 % isopropanol with 1M NaCl.


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