High-throughput screening is a regular approach available for identitying new lead compounds for the growing validated drug targets in drug screening. However, it has also introduced a large number of peculiar molecules which interfere drug screening. Pan assay interference compounds (PAINS) interfere with the progress of drug screening in various ways, such as interfering with a biochemical assay, modifying the protein, aggregate-based inhibitors and so on. So it is of vital significance to remove them. This paper has consulted the concept, category of PAINS and reviewed the way of PAINS interfering and the countermeasures to cope with them to direct the approach of high through screening and improve the hits percent.
Drug Discovery ; High-Throughput Screening Assays ; methods

Growing numbers of studies employ cell line-based systematic short interfering RNA (siRNA) screens to study gene functions and to identify drug targets. As multiple sources of variations that are unique to siRNA screens exist, there is a growing demand for a computational tool that generates normalized values and standardized scores. However, only a few tools have been available so far with limited usability. Here, we present siMacro, a fast and easy-to-use Microsoft Office Excel-based tool with a graphic user interface, designed to process single-condition or two-condition synthetic screen datasets. siMacro normalizes position and batch effects, censors outlier samples, and calculates Z-scores and robust Z-scores, with a spreadsheet output of >120,000 samples in under 1 minute.
High-Throughput Screening Assays ; RNA Interference ; RNA, Small Interfering

In vitro compartmentalization (IVC) links genotype and phenotype by compartmentalizing individual genes (including expression system) or cells into a micro-droplet reaction region. Combined with fluorescence-activated cell sorting (FACS), it can detect and separate single droplets in ultra-high throughput. IVC-FACS screening method has been widely used in protein engineering, enzyme directed evolution, etc. However, it is difficult to control the homogeneity of droplet size by mechanical dispersion method in previous studies, which seriously affects the quantitative detection of droplets and reduces the efficiency and accuracy of this screening method. With the rapid development of microfluidic chip manufacturing technology, the microfluidic chip-based methods for droplet generation are becoming more efficient and controllable. In this study, firstly, the water-in-oil (W/O) single-layer droplet generation chip was used to prepare single-layer monodisperse W1/O droplets at a high generation frequency, and then the W1/O droplets were reinjected into water-in-oil-in-water (W/O/W) double-layer droplet generation chip to prepare uniform W1/O/W2 double-layer emulsion droplets. By optimizing the flow rate and ratio of the oil and water phases, a single-layer micro-droplet can be generated with a diameter range from 15.4 to 23.2 μm and remain stable for several days under normal incubation. Then the single-layer droplets were reinjected into the double emulsion generation chip. By adjusting the flow rate of drop phase, oil phase and water phase, the double-layer emulsion droplets with a diameter range from 30 to 100 μm at a rate of 1 000 droplets/s could be obtained. Escherichia coli embedded in the double-layer emulsion droplets could be cultured and induced for protein expression. This study lays a foundation for the establishment of a high-throughput screening method based on the droplet and flow cytometry.
Emulsions ; Flow Cytometry ; High-Throughput Screening Assays ; Microfluidics ; methods

Tyrosine is an important aromatic amino acid. Besides its nutritional value, tyrosine is also an important precursor for the synthesis of coumarins and flavonoids. Previously, our laboratory constructed a Saccharomyces cerevisiae strain LTH0 (ARO4K229L, ARO7G141S, Δaro10, Δzwf1, Δura3) where tyrosine feedback inhibition was released. In the present study, heterologous expression of betaxanthins synthesis genes DOD (from Mirabilis jalapa) and CYP76AD1 (from sugar beet B. vulgaris) in strain LTH0 enabled production of yellow fluorescence. The engineered strain LTH0-DOD-CYP76AD1 was subjected to UV combined with ARTP mutagenesis, followed by flow cytometry screening. Among the mutants screened, the fluorescence intensity of the mutant strain LTH2-5-DOD-CYP76AD1 at the excitation wavelength of 485 nm and emission wavelength of 505 nm was (5 941±435) AU/OD, which was 8.37 times higher than that of strain LTH0-DOD-CYP76AD1. Fourteen mutant strains were subjected to fermentation to evaluate their tyrosine producing ability. The highest extracellular tyrosine titer reached 26.8 mg/L, which was 3.96 times higher than that of strain LTH0-DOD-CYP76AD1. Heterologous expression of the tyrosine ammonia lyase FjTAL derived from Flavobacterium johnsoniae further increased the titer of coumaric acid to 119.8 mg/L, which was 1.02 times higher than that of the original strain LTH0-FjTAL.
Flavobacterium ; High-Throughput Screening Assays ; Mirabilis ; Saccharomyces cerevisiae/genetics* ; Tyrosine

Amino acids are the basic building blocks of protein that are very important to the nutrition and health of humans and animals, and widely used in feed, food, medicine and daily chemicals. At present, amino acids are mainly produced from renewable raw materials by microbial fermentation, forming one of the important pillar industries of biomanufacturing in China. Amino acid-producing strains are mostly developed through random mutagenesis- and metabolic engineering-enabled strain breeding combined with strain screening. One of the key limitations to further improvement of production level is the lack of efficient, rapid, and accurate strain screening methods. Therefore, the development of high-throughput screening methods for amino acid strains is very important for the mining of key functional elements and the creation and screening of hyper-producing strains. This paper reviews the design of amino acid biosensors and their applications in the high-throughput evolution and screening of functional elements and hyper-producing strains, and the dynamic regulation of metabolic pathways. The challenges of existing amino acid biosensors and strategies for biosensor optimization are discussed. Finally, the importance of developing biosensors for amino acid derivatives is prospected.
Animals ; Humans ; Amino Acids ; Biosensing Techniques ; Metabolic Engineering ; High-Throughput Screening Assays ; China

Enzymes and cell factories are the core of industrial biotechnology. They play important roles in various fields such as medicine, chemical industry, food, agriculture, and energy. Usually, natural enzymes and cells need to be engineered to improve the catalytic efficiency, stability and enantioselectivity. Directed evolution makes it possible to rapidly improve the properties of enzymes and cell factories. Sensitive and reliable high-throughput screening approaches are the key for successful and efficient engineering of enzymes and cell factories. In this review, we first summarize the advantages and disadvantages of different screening methods and signal generation strategies as well as their application scope; we then describe the latest advances of ultra-high throughput screening technology applied in the directed evolution of enzymes and cell factories in the past three years. On this basis, we discuss the limiting factors that need to be further improved for high-throughput screening systems and forecast the future development trends of high-throughput screening methods, hoping that researchers in various fields including biotechnology and instrument development can cooperate closely to enhance the reliability and applicability of the high-throughput screening techniques.
Biotechnology ; Directed Molecular Evolution ; Enzymes ; High-Throughput Screening Assays ; Reproducibility of Results

By constructing mutant libraries and utilizing high-throughput screening methods, directed evolution has emerged as the most popular strategy for protein design nowadays. In the past decade, taking advantages of computer performance and algorithms, computer-assisted protein design has rapidly developed and become a powerful method of protein engineering. Based on the simulation of protein structure and calculation of energy function, computational design can alter the substrate specificity and improve the thermostability of enzymes, as well as de novo design of artificial enzymes with expected functions. Recently, machine learning and other artificial intelligence technologies have also been applied to computational protein engineering, resulting in a series of remarkable applications. Along the lines of protein engineering, this paper reviews the progress and applications of computer-assisted protein design, and current trends and outlooks of the development.
Directed Molecular Evolution ; High-Throughput Screening Assays ; Protein Engineering ; Proteins ; chemistry ; genetics ; metabolism ; Substrate Specificity

Enzymes are closely associated with the onset and progression of numerous diseases, making enzymes a primary target in innovative drug development. However, the challenge remains in identifying compounds that exhibit potent inhibitory effects on the target enzymes. With the continuous expansion of the total number of natural products and increasing difficulty in isolating and enriching new compounds, traditional high-throughput screening methods are finding it increasingly challenging to meet the demands of new drug development. Virtual screening, characterized by its high efficiency and low cost, has gradually become an indispensable technology in drug development. It represents a prominent example of the integration of artificial intelligence with biopharmaceuticals and is an inevitable trend in the rapid development of innovative drug screening in the future. Therefore, this article primarily focused on systematically reviewing the recent applications of virtual screening technology in the development of enzyme inhibitors and explored the prospects and advantages of using this technology in developing new drugs, aiming to provide essential theoretical insights and references for the application of related technologies in the field of new drug development.
Artificial Intelligence ; Enzyme Inhibitors/pharmacology* ; High-Throughput Screening Assays ; Molecular Docking Simulation

The toxicity data of chemicals and drugs increases rapidly, while the animal experimental-based tests method could not meet the current demand of health risk assessment. The high-throughput screening techniques based on in vitro alternative models, integrating with computational methods and information technology to establish toxicity tests strategy promises to address this problem. High-content screening (HCS) technology uses automated microscopy and quantitative image platforms to perform multi-parameter and high-throughput phenotypic analysis via a visualization and quantification manner, and to quickly and effectively assess toxicity and prioritization of chemicals, which promotes the development of in vitro toxicity tests and computational toxicology. HCS technology has been included as an important tool for Toxicity Testing in the 21^st Century (Tox21) and chemical risk prioritization. Its applications have been widely utilized in the research field of toxicity tests and chemical toxicity mechanisms. In this review, we describe the development of HCS technology, technical points, toxicological applications, and the future directions and challenges of HCS, so as to provide references for the toxicity testing technology and risk assessment methodology.
Animals ; High-Throughput Screening Assays ; Research Design ; Risk Assessment ; Toxicity Tests

We have developed a rapid and high throughput lipase-ANS (8-Anilino-l-naphthalenesulfonic acid) assay to evaluate the thermo-stability of lipases based on the ANS fluorescence signal's increasing and shifting when this small fluorescence probes binds to lipase. The testing lipase samples were incubated at a temperature range of 25 degrees C to 65 degrees C for 30 min before mixed with ANS solution (0.20 mg/mL lipase and 0.05 mmol/L ANS in the buffer of 20 mmol/L Tris-HCl, 100 mmol/L NaCl, pH 7.2) in a cuvette or microplate. Fluorescence signals of the samples were measured at EX 378 nm, EM 465 nm with a fluorescence photometer or a plate reader, and Tm was calculated with the software of GraphPad Prism5.0. The Tm values of several mutants of Penicillium expansum lipase (PEL) were measured with this ANS assay and conventional method simultaneously and the results show that Tm values are comparative and consistent between these methods, suggesting that the lipase-ANS assay is a reliable, rapid and high throughput method for lipase thermo-stability measurement.
Anilino Naphthalenesulfonates ; chemistry ; Enzyme Stability ; High-Throughput Screening Assays ; methods ; Hot Temperature ; Lipase ; metabolism ; Spectrometry, Fluorescence