scholarly journals Enzyme Immobilization on Maghemite Nanoparticles with Improved Catalytic Activity: An Electrochemical Study for Xanthine

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1776 ◽  
Author(s):  
Massimiliano Magro ◽  
Davide Baratella ◽  
Andrea Venerando ◽  
Giulia Nalotto ◽  
Caroline R. Basso ◽  
...  

Generally, enzyme immobilization on nanoparticles leads to nano-conjugates presenting partially preserved, or even absent, biological properties. Notwithstanding, recent research demonstrated that the coupling to nanomaterials can improve the activity of immobilized enzymes. Herein, xanthine oxidase (XO) was immobilized by self-assembly on peculiar naked iron oxide nanoparticles (surface active maghemite nanoparticles, SAMNs). The catalytic activity of the nanostructured conjugate (SAMN@XO) was assessed by optical spectroscopy and compared to the parent enzyme. SAMN@XO revealed improved catalytic features with respect to the parent enzyme and was applied for the electrochemical studies of xanthine. The present example supports the nascent knowledge concerning protein conjugation to nanoparticle as a means for the modulation of biological activity.

2003 ◽  
Vol 775 ◽  
Author(s):  
Mariezabel Markarian ◽  
Jad Jaber ◽  
Yan Xin ◽  
Sara Ghannoum ◽  
Lara I. Halaoui

AbstractThe electrostatic self-assembly of hetero-nanostructured multilayers of metal and semiconductor nanoparticles in polyelectrolytes, the self-assembly dynamics, and electrochemistry at the assembled films is reported. Polyacrylate-capped Pt (<d>=2.5 ± 0.6 nm) and Q-CdS nanoparticles (<d>=3.6 ± 0.5 nm) were assembled in poly(diallyldimethylammonium chloride). The nanoparticle assembly dynamics is shown to be a function of the nanoparticle solution ionic strength and its composition. Electrochemical studies at Pt nanoparticles in PDDA reveal that charge hopping is feasible through the nanocomposite film, and that the catalytic activity of the nanoparticles is retained in the assembled structures.


2018 ◽  
Vol 42 (24) ◽  
pp. 19644-19658 ◽  
Author(s):  
Panagiotis Xerras ◽  
Anna-Maria Bacharidou ◽  
Stavros Kalogiannis ◽  
Franc Perdih ◽  
Marina V. Kirillova ◽  
...  

New copper(ii) compounds with quinolone pefloxacin were synthesized and fully characterized; they exhibit notable catalytic activity and promising biological profiles.


2020 ◽  
Vol 2020 (3) ◽  
pp. 54-61
Author(s):  
S.E. Litvin ◽  
◽  
Yu.A. Kurapov ◽  
E.M. Vazhnichaya ◽  
Ya.A. Stel’makh ◽  
...  

2019 ◽  
Vol 25 (24) ◽  
pp. 2661-2676 ◽  
Author(s):  
Sundaresan Bhavaniramya ◽  
Ramar Vanajothi ◽  
Selvaraju Vishnupriya ◽  
Kumpati Premkumar ◽  
Mohammad S. Al-Aboody ◽  
...  

Enzymes exhibit a great catalytic activity for several physiological processes. Utilization of immobilized enzymes has a great potential in several food industries due to their excellent functional properties, simple processing and cost effectiveness during the past decades. Though they have several applications, they still exhibit some challenges. To overcome the challenges, nanoparticles with their unique physicochemical properties act as very attractive carriers for enzyme immobilization. The enzyme immobilization method is not only widely used in the food industry but is also a component methodology in the pharmaceutical industry. Compared to the free enzymes, immobilized forms are more robust and resistant to environmental changes. In this method, the mobility of enzymes is artificially restricted to changing their structure and properties. Due to their sensitive nature, the classical immobilization methods are still limited as a result of the reduction of enzyme activity. In order to improve the enzyme activity and their properties, nanomaterials are used as a carrier for enzyme immobilization. Recently, much attention has been directed towards the research on the potentiality of the immobilized enzymes in the food industry. Hence, the present review emphasizes the different types of immobilization methods that is presently used in the food industry and other applications. Various types of nanomaterials such as nanofibers, nanoflowers and magnetic nanoparticles are significantly used as a support material in the immobilization methods. However, several numbers of immobilized enzymes are used in the food industries to improve the processing methods which not only reduce the production cost but also the effluents from the industry.


1999 ◽  
Vol 64 (8) ◽  
pp. 1211-1252 ◽  
Author(s):  
Jan Hlaváček ◽  
Renáta Marcová

The first part of this review deals with the biosynthesis and a biological function of strongly vasoactive peptides named endothelins (ETs) including vasoactive intestinal contractor. Where it was useful, snake venoms sarafotoxins which are structural endothelin derivatives, were also mentioned. In the second part, an attention is paid to structural basis of the ETs biological activity, with respect to alterations of amino acid residues in the parent peptides modifying the conformation and consequently the physico-chemical and biological properties in corresponding ETs analogs. Special attention is focussed on the area of ETs receptors and their interaction with peptide and non peptide agonists and antagonists, important in designing selective inhibitors of ETs receptors potentially applicable as drugs in a medicine. A review with 182 references.


Author(s):  
Agnieszka Kołodziejczak-Radzimska ◽  
Long D. Nghiem ◽  
Teofil Jesionowski

Abstract Purpose of Review Untreated wastewater discharge can significantly and negatively impact the state of the environment. Rapid industrialization and economic development have directly contributed to land and water pollution resulting from the application of many chemicals such as organic dyes, pharmaceuticals, and industrial reagents. The removal of these chemicals before effluent discharge is crucial for environmental protection. This review aims to explore the importance of functionalized materials in the preparation of biocatalytic systems and consider their application in eliminating water pollutants. Recent Findings Wastewater treatment methods can be classified into three groups: (i) chemical (e.g., chemical oxidation and ozonation), (ii) physical (e.g., membrane separation and ion exchange), and (iii) biological processes. Biological treatment is the most widely used method due to its cost-effectiveness and eco-friendliness. In particular, the use of immobilized enzymes has recently become more attractive as a result of scientific progress in advanced material synthesis. The selection of an appropriate support plays an important role in the preparation of such biologically active systems. Recent studies have demonstrated the use of various materials for enzyme immobilization in the purification of water. Summary This review identifies and discusses different biocatalytic systems used in the enzymatic degradation of various water pollutants. Materials functionalized by specific groups can serve as good support matrices for enzyme immobilization, providing chemical and thermal stability to support catalytic reactions. Enzymatic biocatalysis converts the pollutants into simpler products, which are usually less toxic than their parents. Due to immobilization, the enzyme can be used over multiple cycles to reduce the cost of wastewater treatment. Future studies in this field should focus on developing new platforms for enzyme immobilization in order to improve degradation efficiency.


Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2280
Author(s):  
Tomasz Koczorowski ◽  
Wojciech Szczolko ◽  
Anna Teubert ◽  
Tomasz Goslinski

The syntheses, spectral UV–Vis, NMR, and electrochemical as well as photocatalytic properties of novel magnesium(II) and zinc(II) symmetrical sulfanyl porphyrazines with 2-(morpholin-4-yl)ethylsulfanyl peripheral substituents are presented. Both porphyrazine derivatives were synthesized in cyclotetramerization reactions and subsequently embedded on the surface of commercially available P25 titanium(IV) oxide nanoparticles. The obtained macrocyclic compounds were broadly characterized by ESI MS spectrometry, 1D and 2D NMR techniques, UV–Vis spectroscopy, and subjected to electrochemical studies. Both hybrid materials, consisting of porphyrazine derivatives embedded on the titanium(IV) oxide nanoparticles’ surface, were characterized in terms of particle size and distribution. Next, they were subjected to photocatalytic studies with 1,3-diphenylisobenzofuran, a known singlet oxygen quencher. The applicability of the obtained hybrid material consisting of titanium(IV) oxide P25 nanoparticles and magnesium(II) porphyrazine derivative was assessed in photocatalytic studies with selected active pharmaceutical ingredients, such as diclofenac sodium salt and ibuprofen.


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