scholarly journals Construction and characterization of a functional chimeric laccase from metagenomes suitable as a biocatalyst

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nobuya Itoh ◽  
Yuya Hayashi ◽  
Serina Honda ◽  
Yuna Yamamoto ◽  
Daichi Tanaka ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Thermal Stability ◽  
Target Gene ◽  
High Thermal Stability ◽  
Core Enzyme ◽  
Homologous Genes ◽  
N Terminus ◽  
Hybrid Genes ◽  
Copper Oxidase

AbstractScreening of gene-specific amplicons from metagenomes (S-GAM) is an efficient technique for the isolation of homologous genes from metagenomes. Using the S-GAM approach, we targeted multi-copper oxidase (MCO) genes including laccase and bilirubin oxidase (BOX) in soil and compost metagenomes, and successfully isolated novel MCO core regions. These core enzyme genes shared approximately 70% identity with that of the putative MCO from Micromonospora sp. MP36. According to the principle of S-GAM, the N- and C-terminal regions of the deduced products of the mature gene come from the known parent gene, which should be homologous and compatible with the target gene. We constructed two different MCO hybrid genes using Bacillus subtilis BOX and Micromonospora sp. MP36 MCO, to give Bs-mg-mco and Mic-mg-mco, respectively. The constructed chimeric MCO genes were fused with the maltose-binding protein (MBP) gene at the N-terminus for expression in Escherichia coli cells. We found that MBP-Mic-mg-MCO/Mic-mg-MCO possessed the characteristic properties of laccase, although MBP-Bs-mg-MCO had no activity. This novel laccase (Mic-mg-MCO) demonstrated unique substrate specificity, sufficient activity at neutral pH, and high thermal stability, which are suitable properties for its use as a laccase biocatalyst.

Characterization of Thermal Stability of the Escherichia coli Fapy–DNA Glycosylase

2001 ◽  
Vol 288 (1) ◽  
pp. 121-128 ◽  
Author(s):  
Serguei V. Kuznetsov ◽  
Olga M. Sidorkina ◽  
Jacques Laval ◽  
Anjum Ansari
Keyword(s):  
Escherichia Coli ◽  
Thermal Stability ◽  
Dna Glycosylase ◽  
Thermal Stability Of

Synthesis and characterization of a chromium-piperazinium phosphate with unusual high thermal stability

2012 ◽  
Vol 536 ◽  
pp. S485-S487 ◽  
Author(s):  
A. Espina ◽  
S.A. Khainakov ◽  
J.R. García ◽  
I. de Pedro ◽  
J. Rodríguez Fernández ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Thermal Stability ◽  
Synthesis And Characterization

High Thermal Stability of Mo/Si3N4/Mo/Si3N4/SiO2 Multilayer Solar Selective Coatings

2015 ◽  
Vol 1102 ◽  
pp. 67-71 ◽  
Author(s):  
Rui Hua Yang ◽  
Jin Yang Liu ◽  
Li Mei Lin ◽  
Fa Chun Lai ◽  
Yan Qu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Multilayer Structure ◽  
High Thermal Stability ◽  
Solar Absorptance ◽  
Selective Coating ◽  
Thermal Emittance ◽  
Quartz Substrates ◽  
Thermal Stability Of

In terms of good optical properties and high thermal stability, Mo/Si3N4/Mo/Si3N4/SiO2 coatings based on metal/dielectric multilayer structure were adapted to the solar selective coating at high operating temperatures. The coatings exhibited high solar absorptance in the range of 0.924 ~ 0.936 and low thermal emittance of 0.114 ~ 0.118. The coatings deposited on quartz substrates were thermally stable up to 625 °C in air for 2 h, while they were degraded at 650 °C from the characterization of the absorptance and emittance. The degradation of the coatings was mainly due to the oxidation of molybdenum in air, which was confirmed by Raman spectroscopy. Compared with the thermal stability in air, the coatings were much more stable in vacuum under high temperature. The remarkable thermal stability of the Mo/Si3N4/Mo/Si3N4/SiO2 coatings in air and in vacuum makes them suitable to be applied at high temperature applications.

scholarly journals Molecular Characterization of Cycloinulooligosaccharide Fructanotransferase from Bacillus macerans

2001 ◽  
Vol 67 (2) ◽  
pp. 995-1000 ◽  
Author(s):  
Hwa-Young Kim ◽  
Yong-Jin Choi
Keyword(s):  
Escherichia Coli ◽  
Thermal Stability ◽  
Striking Difference ◽  
Bacillus Macerans ◽  
Specific Manner ◽  
Specificity Constant ◽  
Processing Event ◽  
Hydrolysis Of ◽  
Thermal Stability Of

ABSTRACT Cycloinulooligosaccharide fructanotransferase (CFTase) converts inulin into cyclooligosaccharides of β-(2→1)-linkedd-fructofuranose by catalyzing an intramolecular transfructosylation reaction. The CFTase gene was cloned and characterized from Bacillus macerans CFC1. The CFTase gene encoded a polypeptide of 1,333 amino acids with a calculatedM r of 149,563. Western blot and zymography analyses revealed that the CFTase with a molecular mass of 150 kDa (CFT150) was processed (between Ser389 and Phe390 residue) to form a 107-kDa protein (CFT107) in the B. macerans CFC1 cells. The processed CFT107 was similar in its mass to the previously purified CFTase from B. macerans CFC1. The CFT107 enzyme was produced by B. macerans CFC1 but was not detected from the recombinant Escherichia coli cells, indicating that the processing event occurred in a host-specific manner. The two CFTases (CFT150 and CFT107) exhibited the same enzymatic properties, such as influences of pH and temperature on the enzyme activity, the intermolecular transfructosylation ability, and the ability of hydrolysis of cycloinulooligosaccharides produced by the cyclization reaction. However, the thermal stability of CFT107 was slightly higher than that of CFT150. The most striking difference between the two enzymes was observed in their Km values; the value for CFT150 (1.56 mM) was threefold lower than that for CFT107 (4.76 mM). Thus, the specificity constant (k cat/Km ) of CFT150 was about fourfold higher than that of CFT107. These results indicated that the N-terminal 358-residue region of CFT150 played a role in increasing the enzyme's binding affinity to the inulin substrate.

Fabrication and Dielectric Characterization of Advanced BaTiO3 /Polyimide Nanocomposite Films with High Thermal Stability

2008 ◽  
Vol 18 (10) ◽  
pp. 1509-1517 ◽  
Author(s):  
Zhi-Min Dang ◽  
You-Qin Lin ◽  
Hai-Ping Xu ◽  
Chang-Yong Shi ◽  
Sheng-Tao Li ◽  
...  
Keyword(s):  
Thermal Stability ◽  
High Thermal Stability ◽  
Nanocomposite Films ◽  
Dielectric Characterization ◽  
Polyimide Nanocomposite

scholarly journals Biochemical and Structural Characterization of the Subclass B1 Metallo-β-Lactamase VIM-4

2010 ◽  
Vol 55 (3) ◽  
pp. 1248-1255 ◽  
Author(s):  
Patricia Lassaux ◽  
Daouda A. K. Traoré ◽  
Elodie Loisel ◽  
Adrien Favier ◽  
Jean-Denis Docquier ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Escherichia Coli ◽  
Thermal Stability ◽  
Pseudomonas Aeruginosa ◽  
Structural Characterization ◽  
Catalytic Efficiency ◽  
X Ray ◽  
Stabilizing Effect ◽  
Loop 2

ABSTRACTThe metallo-β-lactamase VIM-4, mainly found inPseudomonas aeruginosaorAcinetobacter baumannii, was produced inEscherichia coliand characterized by biochemical and X-ray techniques. A detailed kinetic study performed in the presence of Zn2+at concentrations ranging from 0.4 to 100 μM showed that VIM-4 exhibits a kinetic profile similar to the profiles of VIM-2 and VIM-1. However, VIM-4 is more active than VIM-1 against benzylpenicillin, cephalothin, nitrocefin, and imipenem and is less active than VIM-2 against ampicillin and meropenem. The crystal structure of the dizinc form of VIM-4 was solved at 1.9 Å. The sole difference between VIM-4 and VIM-1 is found at residue 228, which is Ser in VIM-1 and Arg in VIM-4. This substitution has a major impact on the VIM-4 catalytic efficiency compared to that of VIM-1. In contrast, the differences between VIM-2 and VIM-4 seem to be due to a different position of the flapping loop and two substitutions in loop 2. Study of the thermal stability and the activity of the holo- and apo-VIM-4 enzymes revealed that Zn2+ions have a pronounced stabilizing effect on the enzyme and are necessary for preserving the structure.

Production and Characterization of a Novel Laccase with Cold Adaptation and High Thermal Stability from an Isolated Fungus

2009 ◽  
Vol 162 (1) ◽  
pp. 280-294 ◽  
Author(s):  
Zhixin Wang ◽  
Yujie Cai ◽  
Xiangru Liao ◽  
Feng Zhang ◽  
Dabing Zhang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Cold Adaptation ◽  
High Thermal Stability
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