Improved Soluble Expression and Catalytic Activity of a Thermostable Esterase Using a High-Throughput Screening System Based on a Split-GFP Assembly

2018 ◽  
Vol 66 (48) ◽  
pp. 12756-12764 ◽  
Author(s):  
Hong-Mei Mo ◽  
Yan Xu ◽  
Xiao-Wei Yu
Keyword(s):  
Catalytic Activity ◽  
High Throughput ◽  
High Throughput Screening ◽  
Soluble Expression ◽  
Screening System

Directed Evolution of P450 Fatty Acid Decarboxylases via High-Throughput Screening Towards Improved Catalytic Activity

2019 ◽  
Author(s):  
Huifang Xu ◽  
Weinan Liang ◽  
Linlin Ning ◽  
Yuanyuan Jiang ◽  
Wenxia Yang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Fatty Acid ◽  
Directed Evolution ◽  
High Throughput ◽  
High Throughput Screening ◽  
Colorimetric Detection ◽  
Screening Method ◽  
Random Mutagenesis ◽  
Direct Production ◽  
Consumption Activity

P450 fatty acid decarboxylases (FADCs) have recently been attracting considerable attention owing to their one-step direct production of industrially important 1-alkenes from biologically abundant feedstock free fatty acids under mild conditions. However, attempts to improve the catalytic activity of FADCs have met with little success. Protein engineering has been limited to selected residues and small mutant libraries due to lack of an effective high-throughput screening (HTS) method. Here, we devise a catalase-deficient <i>Escherichia coli</i> host strain and report an HTS approach based on colorimetric detection of H<sub>2</sub>O<sub>2</sub>-consumption activity of FADCs. Directed evolution enabled by this method has led to effective identification for the first time of improved FADC variants for medium-chain 1-alkene production from both DNA shuffling and random mutagenesis libraries. Advantageously, this screening method can be extended to other enzymes that stoichiometrically utilize H<sub>2</sub>O<sub>2</sub> as co-substrate.

scholarly journals A High-Throughput Screening System Based on Fluorescence-Activated Cell Sorting for the Directed Evolution of Chitinase A

2021 ◽  
Vol 22 (6) ◽  
pp. 3041
Author(s):  
Gheorghita Menghiu ◽  
Vasile Ostafe ◽  
Radivoje Prodanović ◽  
Rainer Fischer ◽  
Raluca Ostafe
Keyword(s):  
High Throughput ◽  
Cell Sorting ◽  
High Throughput Screening ◽  
Screening Method ◽  
Enzymatic Reaction ◽  
Hydrolytic Enzymes ◽  
Screening System ◽  
Fluorescence Activated Cell Sorting ◽  
Fungal Cell ◽  
Chitinase A

Chitinases catalyze the degradation of chitin, a polymer of N-acetylglucosamine found in crustacean shells, insect cuticles, and fungal cell walls. There is great interest in the development of improved chitinases to address the environmental burden of chitin waste from the food processing industry as well as the potential medical, agricultural, and industrial uses of partially deacetylated chitin (chitosan) and its products (chito-oligosaccharides). The depolymerization of chitin can be achieved using chemical and physical treatments, but an enzymatic process would be more environmentally friendly and more sustainable. However, chitinases are slow-acting enzymes, limiting their biotechnological exploitation, although this can be overcome by molecular evolution approaches to enhance the features required for specific applications. The two main goals of this study were the development of a high-throughput screening system for chitinase activity (which could be extrapolated to other hydrolytic enzymes), and the deployment of this new method to select improved chitinase variants. We therefore cloned and expressed the Bacillus licheniformis DSM8785 chitinase A (chiA) gene in Escherichia coli BL21 (DE3) cells and generated a mutant library by error-prone PCR. We then developed a screening method based on fluorescence-activated cell sorting (FACS) using the model substrate 4-methylumbelliferyl β-d-N,N′,N″-triacetyl chitotrioside to identify improved enzymes. We prevented cross-talk between emulsion compartments caused by the hydrophobicity of 4-methylumbelliferone, the fluorescent product of the enzymatic reaction, by incorporating cyclodextrins into the aqueous phases. We also addressed the toxicity of long-term chiA expression in E. coli by limiting the reaction time. We identified 12 mutants containing 2–8 mutations per gene resulting in up to twofold higher activity than wild-type ChiA.

scholarly journals Creation of Novel Protein Transduction Domain (PTD) Mutants by a Phage Display-Based High-Throughput Screening System

2006 ◽  
Vol 29 (8) ◽  
pp. 1570-1574 ◽  
Author(s):  
Yohei Mukai ◽  
Toshiki Sugita ◽  
Tomoko Yamato ◽  
Natsue Yamanada ◽  
Hiroko Shibata ◽  
...  
Keyword(s):  
Phage Display ◽  
High Throughput ◽  
High Throughput Screening ◽  
Protein Transduction ◽  
Protein Transduction Domain ◽  
Screening System ◽  
Novel Protein

scholarly journals A Fully Automated High-Throughput Flow Cytometry Screening System Enabling Phenotypic Drug Discovery

2018 ◽  
Vol 23 (7) ◽  
pp. 697-707 ◽  
Author(s):  
John Joslin ◽  
James Gilligan ◽  
Paul Anderson ◽  
Catherine Garcia ◽  
Orzala Sharif ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Drug Discovery ◽  
High Throughput ◽  
High Throughput Screening ◽  
Screening System ◽  
Preclinical Development ◽  
Drug Identification ◽  
Therapeutic Setting ◽  
Compound Libraries ◽  
Automated Platform

The goal of high-throughput screening is to enable screening of compound libraries in an automated manner to identify quality starting points for optimization. This often involves screening a large diversity of compounds in an assay that preserves a connection to the disease pathology. Phenotypic screening is a powerful tool for drug identification, in that assays can be run without prior understanding of the target and with primary cells that closely mimic the therapeutic setting. Advanced automation and high-content imaging have enabled many complex assays, but these are still relatively slow and low throughput. To address this limitation, we have developed an automated workflow that is dedicated to processing complex phenotypic assays for flow cytometry. The system can achieve a throughput of 50,000 wells per day, resulting in a fully automated platform that enables robust phenotypic drug discovery. Over the past 5 years, this screening system has been used for a variety of drug discovery programs, across many disease areas, with many molecules advancing quickly into preclinical development and into the clinic. This report will highlight a diversity of approaches that automated flow cytometry has enabled for phenotypic drug discovery.

scholarly journals High-throughput screening of high lactic acid-producing Bacillus coagulans by droplet microfluidic based flow cytometry with fluorescence activated cell sorting

RSC Advances ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 4507-4513 ◽  
Author(s):  
Xu-Dong Zhu ◽  
Xiang Shi ◽  
Shu-Wen Wang ◽  
Ju Chu ◽  
Wei-Hong Zhu ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Lactic Acid ◽  
High Throughput ◽  
Cell Sorting ◽  
High Throughput Screening ◽  
Bacillus Coagulans ◽  
Screening System ◽  
Fluorescence Activated Cell Sorting ◽  
Microfluidic Sorting

A high-throughput screening system based on droplet microfluidic sorting was developed and employed for screening of high lactic acid-producing Bacillus coagulans.

A high-throughput screening system for genes extending life-span

2003 ◽  
Vol 38 (10) ◽  
pp. 1051-1063 ◽  
Author(s):  
Cuiying Chen ◽  
Sylviane Dewaele ◽  
Bart Braeckman ◽  
Liesbeth Desmyter ◽  
Jan Verstraelen ◽  
...  
Keyword(s):  
Life Span ◽  
High Throughput ◽  
High Throughput Screening ◽  
Screening System
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