scholarly journals Characterization of Two NMN Deamidase Mutants as Possible Probes for an NMN Biosensor

2021 ◽  
Vol 22 (12) ◽  
pp. 6334
Author(s):  
Alessandra Camarca ◽  
Gabriele Minazzato ◽  
Angela Pennacchio ◽  
Alessandro Capo ◽  
Adolfo Amici ◽  
...  
Keyword(s):  
Enzymatic Reaction ◽  
Promising Candidate ◽  
Beneficial Effects ◽  
Steady State Fluorescence ◽  
Nicotinamide Mononucleotide ◽  
Recognition Elements ◽  
Steady State Fluorescence Spectroscopy ◽  
Similar Affinity ◽  
Micromolar Range

Nicotinamide mononucleotide (NMN) is a key intermediate in the nicotinamide adenine dinucleotide (NAD+) biosynthesis. Its supplementation has demonstrated beneficial effects on several diseases. The aim of this study was to characterize NMN deamidase (PncC) inactive mutants to use as possible molecular recognition elements (MREs) for an NMN-specific biosensor. Thermal stability assays and steady-state fluorescence spectroscopy measurements were used to study the binding of NMN and related metabolites (NaMN, Na, Nam, NR, NAD, NADP, and NaAD) to the PncC mutated variants. In particular, the S29A PncC and K61Q PncC variant forms were selected since they still preserve the ability to bind NMN in the micromolar range, but they are not able to catalyze the enzymatic reaction. While S29A PncC shows a similar affinity also for NaMN (the product of the PncC catalyzed reaction), K61Q PncC does not interact significantly with it. Thus, PncC K61Q mutant seems to be a promising candidate to use as specific probe for an NMN biosensor.

Computer Simulation of Amperometric Biosensor Response to Mixtures of Compounds

2002 ◽  
Vol 7 (2) ◽  
pp. 3-14 ◽  
Author(s):  
R. Baronas ◽  
J. Christensen ◽  
F. Ivanauskas ◽  
J. Kulys
Keyword(s):  
Computer Simulation ◽  
Enzymatic Reaction ◽  
Diffusion Equations ◽  
Response Data ◽  
Finite Difference Technique ◽  
Stationary Diffusion ◽  
Biosensor Array ◽  
Menten Kinetic ◽  
Biosensor Response

A mathematical model of amperometric biosensors has been developed. The model bases on non-stationary diffusion equations containing a non-linear term related to Michaelis-Menten kinetic of the enzymatic reaction. The model describes the biosensor response to mixtures of multiple compounds in two regimes of analysis: batch and flow injection. Using computer simulation, large amount of biosensor response data were synthesised for calibration of a biosensor array to be used for characterization of wastewater. The computer simulation was carried out using the finite difference technique.

scholarly journals Tyrosinase Nanoparticles: Understanding the Melanogenesis Pathway by Isolating the Products of Tyrosinase Enzymatic Reaction

2021 ◽  
Vol 22 (2) ◽  
pp. 734
Author(s):  
Paul K. Varghese ◽  
Mones Abu-Asab ◽  
Emilios K. Dimitriadis ◽  
Monika B. Dolinska ◽  
George P. Morcos ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Large Scale ◽  
Magnetic Beads ◽  
Enzymatic Reaction ◽  
Oculocutaneous Albinism ◽  
Transmission Electron ◽  
Hill Kinetics ◽  
Rate Limiting ◽  
Human Tyrosinase

Human Tyrosinase (Tyr) is the rate-limiting enzyme of the melanogenesis pathway. Tyr catalyzes the oxidation of the substrate L-DOPA into dopachrome and melanin. Currently, the characterization of dopachrome-related products is difficult due to the absence of a simple way to partition dopachrome from protein fraction. Here, we immobilize catalytically pure recombinant human Tyr domain (residues 19–469) containing 6xHis tag to Ni-loaded magnetic beads (MB). Transmission electron microscopy revealed Tyr-MB were within limits of 168.2 ± 24.4 nm while the dark-brown melanin images showed single and polymerized melanin with a diameter of 121.4 ± 18.1 nm. Using Hill kinetics, we show that Tyr-MB has a catalytic activity similar to that of intact Tyr. The diphenol oxidase reactions of L-DOPA show an increase of dopachrome formation with the number of MB and with temperature. At 50 °C, Tyr-MB shows some residual catalytic activity suggesting that the immobilized Tyr has increased protein stability. In contrast, under 37 °C, the dopachrome product, which is isolated from Tyr-MB particles, shows that dopachrome has an orange-brown color that is different from the color of the mixture of L-DOPA, Tyr, and dopachrome. In the future, Tyr-MB could be used for large-scale productions of dopachrome and melanin-related products and finding a treatment for oculocutaneous albinism-inherited diseases.

scholarly journals Rhizosphere-enriched microbes as a pool to design synthetic communities for reproducible beneficial outputs

2019 ◽  
Author(s):  
Maria-Dimitra Tsolakidou ◽  
Ioannis A Stringlis ◽  
Natalia Fanega-Sleziak ◽  
Stella Papageorgiou ◽  
Antria Tsalakou ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Fungal Pathogens ◽  
Growth Parameters ◽  
Tomato Plants ◽  
Beneficial Effects ◽  
Negative Effect ◽  
Tomato Growth ◽  
In Vitro Antifungal Activity

Abstract Composts represent a sustainable way to suppress diseases and improve plant growth. Identification of compost-derived microbial communities enriched in the rhizosphere of plants and characterization of their traits, could facilitate the design of microbial synthetic communities (SynComs) that upon soil inoculation could yield consistent beneficial effects towards plants. Here, we characterized a collection of compost-derived bacteria, previously isolated from tomato rhizosphere, for in vitro antifungal activity against soil-borne fungal pathogens and for their potential to change growth parameters in Arabidopsis. We further assessed root-competitive traits in the dominant rhizospheric genus Bacillus. Certain isolated rhizobacteria displayed antifungal activity against the tested pathogens and affected growth of Arabidopsis, and Bacilli members possessed several enzymatic activities. Subsequently, we designed two SynComs with different composition and tested their effect on Arabidopsis and tomato growth and health. SynCom1, consisting of different bacterial genera, displayed negative effect on Arabidopsis in vitro, but promoted tomato growth in pots. SynCom2, consisting of Bacilli, didn't affect Arabidopsis growth, enhanced tomato growth and suppressed Fusarium wilt symptoms. Overall, we found selection of compost-derived microbes with beneficial properties in the rhizosphere of tomato plants, and observed that application of SynComs on poor substrates can yield reproducible plant phenotypes.

Facile Synthesis of Cu2O Nanocubes in Triblock Copolymer Solutions

2007 ◽  
Vol 121-123 ◽  
pp. 275-278
Author(s):  
Jin Hua Jiang ◽  
Qiu Ming Gao
Keyword(s):  
Triblock Copolymer ◽  
Solar Spectrum ◽  
Blue Shift ◽  
Edge Length ◽  
Promising Candidate ◽  
Organic Species ◽  
Transmission Electron ◽  
Ft Ir ◽  
Average Edge Length

Cuprous oxide and related materials in nanosizes are of much interest and investigated extensively recently. It is reported here that cubic Cu2O nanocubes were synthesized successfully in aqueous solutions at room temperature in air condition. Copper (II) salts in water were reduced with ascorbate acid in air, using the nonionic pluronic amphiphilic triblock copolymer EO20PO70EO20 (P123) as the template-directing and protecting agent. The average edge length of the cubes varied from 50 to 100 nm. Transmission electron microscopy (TEM) has been used for the shape and structural characterization of the obtained Cu2O nanocubes. The UV-Vis spectra showed an obvious blue-shift (0.53 eV), compared to the band gap of the bulk Cu2O crystal, which makes it a promising candidate in solar energy conversion since this sample can make use of higher energy visible rays of solar spectrum. In the FT-IR spectra the peak of Cu-O bond for the Cu2O is clearly distinguished and several weak peaks of the C-H, C-C and C=O bonds for the organic species can also be detectable, implying a little P123 residua in the products. The effect of the triblock copolymer P123 on the growth of the Cu2O nanocubes is discussed.

scholarly journals Conjuring up a ghost: structural and functional characterization of FhuF, a ferric siderophore reductase from E. coli

2021 ◽  
Author(s):  
I. B. Trindade ◽  
G. Hernandez ◽  
E. Lebègue ◽  
F. Barrière ◽  
T. Cordeiro ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Paramagnetic Nmr ◽  
E Coli ◽  
The Past ◽  
Internal Cavities ◽  
Structural Differences ◽  
Bond Strengths ◽  
Redox Bohr Effect ◽  
Micromolar Range

AbstractIron is a fundamental element for virtually all forms of life. Despite its abundance, its bioavailability is limited, and thus, microbes developed siderophores, small molecules, which are synthesized inside the cell and then released outside for iron scavenging. Once inside the cell, iron removal does not occur spontaneously, instead this process is mediated by siderophore-interacting proteins (SIP) and/or by ferric-siderophore reductases (FSR). In the past two decades, representatives of the SIP subfamily have been structurally and biochemically characterized; however, the same was not achieved for the FSR subfamily. Here, we initiate the structural and functional characterization of FhuF, the first and only FSR ever isolated. FhuF is a globular monomeric protein mainly composed by α-helices sheltering internal cavities in a fold resembling the “palm” domain found in siderophore biosynthetic enzymes. Paramagnetic NMR spectroscopy revealed that the core of the cluster has electronic properties in line with those of previously characterized 2Fe–2S ferredoxins and differences appear to be confined to the coordination of Fe(III) in the reduced protein. In particular, the two cysteines coordinating this iron appear to have substantially different bond strengths. In similarity with the proteins from the SIP subfamily, FhuF binds both the iron-loaded and the apo forms of ferrichrome in the micromolar range and cyclic voltammetry reveals the presence of redox-Bohr effect, which broadens the range of ferric-siderophore substrates that can be thermodynamically accessible for reduction. This study suggests that despite the structural differences between FSR and SIP proteins, mechanistic similarities exist between the two classes of proteins. Graphic abstract

scholarly journals An Overview of Metabolic Activity, Beneficial and Pathogenic Aspects of Burkholderia Spp

Metabolites ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 321
Author(s):  
Hazem S. Elshafie ◽  
Ippolito Camele
Keyword(s):  
Secondary Metabolites ◽  
Plant Growth ◽  
Biochemical Characterization ◽  
Bacterial Species ◽  
Promoting Effect ◽  
Important Species ◽  
Beneficial Effects ◽  
Plant Growth Promoting ◽  
Rhizosphere Competence

Burkholderia is an important bacterial species which has different beneficial effects, such as promoting the plant growth, including rhizosphere competence for the secretion of allelochemicals, production of antibiotics, and siderophores. In addition, most of Burkholderia species have demonstrated promising biocontrol action against different phytopathogens for diverse crops. In particular, Burkholderia demonstrates significant biotechnological potential as a source of novel antibiotics and bioactive secondary metabolites. The current review is concerned with Burkholderia spp. covering the following aspects: discovering, classification, distribution, plant growth promoting effect, and antimicrobial activity of different species of Burkholderia, shedding light on the most important secondary metabolites, their pathogenic effects, and biochemical characterization of some important species of Burkholderia, such as B. cepacia, B. andropogonis, B. plantarii, B. rhizoxinica, B. glumae, B. caryophylli and B. gladioli.

scholarly journals Fabrication and Characterization of Al/NiO Energetic Nanomultilayers

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
YiChao Yan ◽  
Wei Shi ◽  
HongChuan Jiang ◽  
Jie Xiong ◽  
WanLi Zhang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Total Thickness ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
Metallic Oxide ◽  
Promising Candidate ◽  
X Ray ◽  
Thermal Boundary Conductance ◽  
Fabrication And Characterization

The redox reaction between Al and metallic oxide has its advantage compared with intermetallic reaction and Al/NiO nanomutlilayers are a promising candidate for enhancing the performance of energetic igniter. Al/NiO nanomutlilayers with different modulation periods are prepared on alumina substrate by direct current (DC) magnetron sputtering. The thicknesses of each period are 250 nm, 500 nm, 750 nm, 1000 nm, and 1500 nm, respectively, and the total thickness is 3 μm. The X-ray diffraction (XRD) and scanning electron microscope (SEM) results of the as-deposited Al/NiO nanomutlilayers show that the NiO films are amorphous and the layered structures are clearly distinguished. The X-ray photoelectron spectroscopy (XPS) demonstrates that the thickness of Al2O3increases on the side of Al monolayer after annealing at 450°C. The thermal diffusion time becomes greater significantly as the amount of thermal boundary conductance across the interfaces increases with relatively smaller modulation period. Differential scanning calorimeter (DSC) curve suggests that the energy release per unit mass is below the theoretical heat of the reaction due to the nonstoichiometric ratio between Al and NiO and the presence of impurities.

scholarly journals The Clash of Microbiomes: From the Food Matrix to the Host Gut

2022 ◽  
Vol 10 (1) ◽  
pp. 116
Author(s):  
Despoina Eugenia Kiousi ◽  
Nikos Chorianopoulos ◽  
Chrysoula C. Tassou ◽  
Alex Galanis
Keyword(s):  
Raw Materials ◽  
Interdisciplinary Collaboration ◽  
Health Benefit ◽  
Potential Health ◽  
Empirical Observation ◽  
New Era ◽  
Host Interactions ◽  
Beneficial Effects ◽  
Organoleptic Characteristics

Food fermentation has led to the improvement of the safety characteristics of raw materials and the production of new foodstuffs with elevated organoleptic characteristics. The empirical observation that these products could have a potential health benefit has garnered the attention of the scientific community. Therefore, several studies have been conducted in animal and human hosts to decipher which of these products may have a beneficial outcome against specific ailments. However, despite the accumulating literature, a relatively small number of products have been authorized as ‘functional foods’ by regulatory bodies. Data inconsistency and lack of in-depth preclinical characterization of functional products could heavily contribute to this issue. Today, the increased availability of omics platforms and bioinformatic algorithms for comprehensive data analysis can aid in the systematic characterization of microbe–microbe, microbe–matrix, and microbe–host interactions, providing useful insights about the maximization of their beneficial effects. The incorporation of these platforms in food science remains a challenge; however, coordinated efforts and interdisciplinary collaboration could push the field toward the dawn of a new era.

scholarly journals POLIMORPHIC CHARACTERIZATION OF ESR1 AND FOXL2 GENES AND THE ASSOCIATION OF THEIR INTERACTION WITH PRODUCTIVE TRAITS OF BROWN LOCAL IRAQI CHICKENS

2021 ◽  
Vol 52 (6) ◽  
pp. 1391-1400
Author(s):  
R. I. A. Abu-Rekaiba ◽  
E. H. AL-Anbari ◽  
W. M. Razuki
Keyword(s):  
Production Performance ◽  
Production Traits ◽  
Chi Square ◽  
Beneficial Effects ◽  
Egg Formation ◽  
Hardy Weinberg Equilibrium ◽  
Productive Traits ◽  
Chi Square Analysis ◽  
New Evidence

The estrogen receptor 1(ESR1) and fork-head box L2 (FOX L2) genes play a pivotal role in regulation of egg formation in poultry. this study aimed to investigate interaction between ESR1 and FOXL2 in the productive performance of brown local Iraqi chickens (BLIC). A total of 104 BLIC represented from the F4th generation of local chicken selected for high egg productions were used. Two novel single nucleotide polymorphism (SNPs), one of them in ESR1 (T57198C) intron 3, and another of FOX L2 (C919T) gene within encoding region were identified through PCR-DNA sequencing. Six haplotypes (H1=TTCC, H2=TTCT, H3=TCCC, H4=TCCT, H5=CCCC, H6=CCCT) were obtained due to interaction between these two SNPs. Chi-square analysis showed no significant  in genotypic and allelic frequencies for each SNP which revealed that both genes were agreement with Hardy-Weinberg equilibrium. Association analysis of haplotypes with production traits revealed that individuals have H4 genotype achieved higher body weight at sexual maturity, at 60 weeks of age and egg weight at 45 and 60 weeks of age, whereas, the higher number of eggs were exhibited in individual with H6 from onset egg till 60 weeks of age. The two haplotypes; H4(TCCT) and H6(CCCT) showed better combination than others with respect to production performance. In conclusion, our findings provided new evidence that the two genes (ESR1 and FOXLl2) with special interaction may have potential effects on productive traits of chickens and beneficial effects in laying breeding programs.

Sign in / Sign up

Export Citation Format

Share Document