Improving the Thermostability of Lipase by Restricting the Flexibility of N-Terminus and C-Terminus Simultaneously via the 25-Loop Substitutions.

(1) Lipases are catalysts widely applied in industrial fields. To sustain the harsh treatments in industries, optimizing lipase activities and thermal stability is necessary to reduce production loss. (2) The thermostability of lipase (TLL) was evaluated via B-factor analysis and consensus-sequence substitutions.

Fecal Metagenomics Study Reveals That a Low-Fiber Diet Drives the Migration of Wild Asian Elephants in Xishuangbanna, China.

The rare northward migration of wild Asian elephants in Xishuangbanna, China, has attracted global attention. Elephant migration is a complex ecological process, and the factors driving this long-distance migration remain elusive. In this study, fresh fecal samples were collected from both captive and wild Asian elephants, along with breastfed calves residing within the Wild Elephant Valley of Xishuangbanna.

Improving the Thermostability of Serine Protease PB92 from via Site-Directed Mutagenesis Based on Semi-Rational Design.

Proteases have been widely employed in many industrial processes. In this work, we aimed to improve the thermostability of the serine protease PB92 from to meet the high-temperature requirements of biotechnological treatments. Eight mutation sites (N18, S97-S101, E110, and R143) were identified, and 21 mutants were constructed from B-factor comparison and multiple sequence alignment and expressed via .

Enhanced Extracellular Expression of a Ca- and Mg-Dependent Hyperthermostable Protease EA1 in Systematic Screening of Optimal Signal Peptides.

Proteases have been widely applied in various industries, including tanning, silk, feed, medicine, food, and environmental protection. Herein, the protease EA1 (GenBank accession no. U25630.

Discovery of the Key Mutation Site Influencing the Thermostability of Lipase by Rosetta Design Programs.

Lipases are remarkable biocatalysts and are broadly applied in many industry fields because of their versatile catalytic capabilities. Considering the harsh biotechnological treatment of industrial processes, the activities of lipase products are required to be maintained under extreme conditions. In our current study, Gibbs free energy calculations were performed to predict potent thermostable lipase (TLL) variants by Rosetta design programs.

Display of a novel carboxylesterase CarCby on Escherichia coli cell surface for carbaryl pesticide bioremediation.

Background: Carbamate pesticides have been widely used in agricultural and forestry pest control. The large-scale use of carbamates has caused severe toxicity in various systems because of their toxic environmental residues. Carbaryl is a representative carbamate pesticide and hydrolase/carboxylesterase is the initial and critical enzyme for its degradation.

Improving the Thermostability of a Fungal GH11 Xylanase via Fusion of a Submodule (C2) from Hyperthermophilic CBM9_1-2.

Xylanases have been applied in many industrial fields. To improve the activity and thermostability of the xylanase CDBFV from (GenBank accession no. KP691331), submodule C2 from hyperthermophilic CBM9_1-2 was inserted into the N- and/or C-terminal regions of the CDBFV protein (producing C2-CDBFV, CDBFV-C2, and C2-CDBFV-C2) by genetic engineering.

[Exploration and practice in ideological education in the course of "Protein and Enzyme Engineering"].

Protein and Enzyme Engineering is the core and required course for colleague students majored in biotechnology, which plays an important role in the professional training system. In accordance with the "Guidelines for the Development of Ideological Education in Higher Education Institutions" issued by the Ministry of Education, we explored the combination of course teaching with ideological education by considering the features of the biotechnology major and the course and setting up rational teaching objectives. This paper described the strategy, design, implementation and evaluation approaches that were used in the course of "Protein and Enzyme Engineering" to achieve a good integration.

Surface charge engineering of Thermomyces lanuginosus lipase improves enzymatic activity and biodiesel synthesis.

Objectives: This study was aimed at engineering charged residues on the surface of Thermomyces lanuginosus lipase (TLL) to obtain TLL variant with elevated performance for industrial applications.

Results: Site-directed mutagenesis of eight charged amino acids on the TLL surface were conducted and substitutions on the negatively charged residues D111, D158, D165, and E239 were identified with elevated specific activities and biodiesel yields. Synergistic effect was not discovered in the double mutants, D111E/D165E and D165E/E239R, when compared with the corresponding single mutants.

Plasticity of the 340-Loop in Influenza Neuraminidase Offers New Insight for Antiviral Drug Development.

The recently discovered 340-cavity in influenza neuraminidase (NA) N6 and N7 subtypes has introduced new possibilities for rational structure-based drug design. However, the plasticity of the 340-loop (residues 342-347) and the role of the 340-loop in NA activity and substrate binding have not been deeply exploited. Here, we investigate the mechanism of 340-cavity formation and demonstrate for the first time that seven of nine NA subtypes are able to adopt an open 340-cavity over 1.

Molecular and Biochemical Characterization of Salt-Tolerant Trehalose-6-Phosphate Hydrolases Identified by Screening and Sequencing Salt-Tolerant Clones From the Metagenomic Library of the Gastrointestinal Tract.

The exploration and utilization of microbial salt-tolerant enzymatic and genetic resources are of great significance in the field of biotechnology and for the research of the adaptation of microorganisms to extreme environments. The presence of new salt-tolerant genes and enzymes in the microbial metagenomic library of the gastrointestinal tract has been confirmed through metagenomic technology. This paper aimed to identify and characterize enzymes that confer salt tolerance in the gastrointestinal tract microbe.

Improving the Thermostability of Lipase Through Site-Directed Mutagenesis Based on B-Factor Analysis.

In order to improve the thermostability of lipases derived from , we identified lipase (Lipr27RCL) mutagenesis sites that were associated with enhanced flexibility based upon B-factor analysis and multiple sequence alignment. We found that two mutated isoforms (Lipr27RCL-K64N and Lipr27RCL-K68T) exhibited enhanced thermostability and improved residual activity, with respective thermal activity retention values of 37.88% and 48.

Enhancing thermal tolerance of a fungal GH11 xylanase guided by B-factor analysis and multiple sequence alignment.

Xylanases, capable of hydrolyzing xylans which are abundant in nature, have been employed as important biocatalyst in many industrial processes. Xylanases with advantageous properties, especially excellent thermostability, are in high demand in industry. In this study, we aim to improve the thermostability of XynCDBFV, a fungal GH11 xylanase.

Characterization of a novel salt-, xylose- and alkali-tolerant GH43 bifunctional β-xylosidase/α-l-arabinofuranosidase from the gut bacterial genome.

A GH43 bifunctional β-xylosidase encoding gene (XylRBM26) was cloned from Massilia sp. RBM26 and successfully expressed in Escherichia coli. Recombinant XylRBM26 exhibited β-xylosidase and α-l-arabinofuranosidase activities.

Oriented covalent immobilization of recombinant protein A on the glutaraldehyde activated agarose support.

High IgG-binding capacity of protein A affinity chromatography is crucial to its application in the antibody purification and autoantibody-associated disease treatment. An oriented immobilization strategy was used to covalently conjugate the recombinant protein A (rSpA) on the glutaraldehyde activated agarose. By controlling the glutaraldehyde concentration, pH and reactivity time, one or two molecules of glutaraldehyde per primary amino group were anchored on agarose supports.

Transcriptome Analysis and Microsatellite Markers Development of a Traditional Chinese Medicinal Herb D. Don (Gentianaceae).

is a popular Chinese medicinal herb that is used to treat jaundice disease and virus hepatitis, and its wild populations have been reduced significantly due to overharvesting recently. However, effective conservation could not be implemented because of the lack of genomic information and genetic markers. In this study, a de novo transcriptome of was sequenced using the NGS Illumina, and 132 695 unigenes with the length >200 bp (base pairs) were obtained.

Enhancing thermal tolerance of Aspergillus niger PhyA phytase directed by structural comparison and computational simulation.

Background: Phytase supplied in feeds for monogastric animals is important for improving nutrient uptake and reducing phosphorous pollution. High-thermostability phytases are particularly desirable due to their ability to withstand transient high temperatures during feed pelleting procedures. A comparison of crystal structures of the widely used industrial Aspergillus niger PhyA phytase (AnP) with its close homolog, the thermostable Aspergillus fumigatus phytase (AfP), suggests 18 residues in three segments associated with thermostability.

A thermostable and alkaline GDSL-motif esterase from Bacillus sp. K91: crystallization and X-ray crystallographic analysis.

The esterase Est8 from the thermophilic bacterium Bacillus sp. K91 belongs to the GDSL family and is active on a variety of acetylated compounds, including 7-aminocephalosporanic acid. In contrast to other esterases of the GDSL family, the catalytic residues Asp182 and His185 were more pivotal for the catalytic activity of Est8 than the Ser11 residue.

Genetic diversity of catechol 1,2-dioxygenase in the fecal microbial metagenome.

Catechol 1,2-dioxygenase is the key enzyme that catalyzes the cleavage of the aromatic ring of catechol. We explored the genetic diversity of catechol 1,2-dioxygenase in the fecal microbial metagenome by PCR with degenerate primers. A total of 35 gene fragments of C12O were retrieved from microbial DNA in the feces of pygmy loris.

Improving the thermostability of a fungal GH11 xylanase via site-directed mutagenesis guided by sequence and structural analysis.

Background: Xylanases have been widely employed in many industrial processes, and thermophilic xylanases are in great demand for meeting the high-temperature requirements of biotechnological treatments. In this work, we aim to improve the thermostability of XynCDBFV, a glycoside hydrolase (GH) family 11 xylanase from the ruminal fungus , by site-directed mutagenesis. We report favorable mutations at the C-terminus from B-factor comparison and multiple sequence alignment.

A Shinella β-N-acetylglucosaminidase of glycoside hydrolase family 20 displays novel biochemical and molecular characteristics.

β-N-Acetylglucosaminidases (GlcNAcases) are important for many biological functions and industrial applications. In this study, a glycoside hydrolase family 20 GlcNAcase from Shinella sp. JB10 was expressed in Escherichia coli BL21 (DE3).

Distinctive molecular and biochemical characteristics of a glycoside hydrolase family 20 β-N-acetylglucosaminidase and salt tolerance.

Background: Enzymatic degradation of chitin has attracted substantial attention because chitin is an abundant renewable natural resource, second only to lignocellulose, and because of the promising applications of N-acetylglucosamine in the bioethanol, food and pharmaceutical industries. However, the low activity and poor tolerance to salts and N-acetylglucosamine of most reported β-N-acetylglucosaminidases limit their applications. Mining for novel enzymes from new microorganisms is one way to address this problem.

Characterization of a novel low-temperature-active, alkaline and sucrose-tolerant invertase.

A glycoside hydrolase family 32 invertase from Bacillus sp. HJ14 was expressed in Escherichia coli. The purified recombinant enzyme (rInvHJ14) showed typical biochemical properties of low-temperature-active and alkaline enzymes: (i) rInvHJ14 was active and stable in the range of pH 7.

NaCl-, protease-tolerant and cold-active endoglucanase from Paenibacillus sp. YD236 isolated from the feces of Bos frontalis.

Bos frontalis, which consumes bamboo and weeds, may have evolved unique gastrointestinal microorganisms that digest cellulase. A Paenibacillus sp. YD236 strain was isolated from B.

Characterization of a NaCl-tolerant β-N-acetylglucosaminidase from Sphingobacterium sp. HWLB1.

β-N-Acetylglucosaminidases serve important biological functions and various industrial applications. A glycoside hydrolase family 3 β-N-acetylglucosaminidase gene was cloned from Sphingobacterium sp. HWLB1 and expressed in Escherichia coli BL21 (DE3).