High-throughput assay of tyrosine phenol-lyase activity using a cascade of enzymatic reactions

2022 ◽  
pp. 114547
Author(s):  
Hang-Qin Zhu ◽  
Wen-Ye Hu ◽  
Xiao-Ling Tang ◽  
Ren-Chao Zheng ◽  
Yu-Guo Zheng
Keyword(s):  
High Throughput ◽  
Enzymatic Reactions ◽  
Lyase Activity ◽  
Tyrosine Phenol Lyase ◽  
High Throughput Assay

Chemical Derivatization Enables MALDI-TOF-Based High-Throughput Screening for Microbial Trimethylamine (TMA)-Lyase Inhibitors

2019 ◽  
Vol 24 (7) ◽  
pp. 766-777 ◽  
Author(s):  
Martin Winter ◽  
Tom Bretschneider ◽  
Sven Thamm ◽  
Carola Kleiner ◽  
Daniel Grabowski ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Enzymatic Reactions ◽  
Chemical Derivatization ◽  
Label Free ◽  
Limited Sample ◽  
Ionization Time ◽  
Maldi Tof ◽  
Recent Advancement ◽  
Lyase Activity

Microbial-dependent trimethylamine (TMA) generation from dietary precursors such as choline was recently linked to cardiovascular diseases (CVDs) as well as chronic kidney disease (CKD). Inhibition of TMA-generating enzymes in gut bacteria would be an innovative approach to treat these diseases. The potential to accurately quantify secreted TMA levels highlights the capacity of mass spectrometry (MS) for tracking microbial TMA-lyase activity. However, high-throughput screening (HTS) by conventional MS instrumentation is hampered by limited sample throughput. Recent advancement in liquid handling and instrumentation of matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS provides an HTS-compatible MS technology. The deciphering of enzymatic reactions using this label-free readout has been successfully applied but has thus far been limited to peptide/protein-centric activity assays. Here, we demonstrate the versatile applicability of MALDI-TOF by tracking a small molecule within a highly complex sample background. The key to success for this concept was chemical derivatization of the target molecule enabling quantitative assessment of microbial TMA formation. Further, its potential was demonstrated in a side-by-side comparison to RapidFire-MS in a primary screen and subsequent dose–response experiments. Overall, the established assay enables the screening for microbial TMA-lyase inhibitors and serves as a proof of concept for the applicability of MALDI-TOF for demanding assay concepts per se.

scholarly journals Development of a High-Throughput Screening Assay to Identify Inhibitors of the SARS-CoV-2 Guanine-N7-Methyltransferase Using RapidFire Mass Spectrometry

2021 ◽  
pp. 247255522110006
Author(s):  
Lesley-Anne Pearson ◽  
Charlotte J. Green ◽  
De Lin ◽  
Alain-Pierre Petit ◽  
David W. Gray ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Mutational Analysis ◽  
Nonstructural Protein ◽  
Translation Efficiency ◽  
Screening Assay ◽  
High Throughput Screening Assay ◽  
Starting Point ◽  
Approved Drugs ◽  
High Throughput Assay

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) represents a significant threat to human health. Despite its similarity to related coronaviruses, there are currently no specific treatments for COVID-19 infection, and therefore there is an urgent need to develop therapies for this and future coronavirus outbreaks. Formation of the cap at the 5′ end of viral RNA has been shown to help coronaviruses evade host defenses. Nonstructural protein 14 (nsp14) is responsible for N7-methylation of the cap guanosine in coronaviruses. This enzyme is highly conserved among coronaviruses and is a bifunctional protein with both N7-methyltransferase and 3′-5′ exonuclease activities that distinguish nsp14 from its human equivalent. Mutational analysis of SARS-CoV nsp14 highlighted its role in viral replication and translation efficiency of the viral genome. In this paper, we describe the characterization and development of a high-throughput assay for nsp14 utilizing RapidFire technology. The assay has been used to screen a library of 1771 Food and Drug Administration (FDA)-approved drugs. From this, we have validated nitazoxanide as a selective inhibitor of the methyltransferase activity of nsp14. Although modestly active, this compound could serve as a starting point for further optimization.

scholarly journals Development of a High-Throughput Method to Study the Inhibitory Effect of Phytochemicals on Trimethylamine Formation

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1466
Author(s):  
Lisard Iglesias-Carres ◽  
Lauren A. Essenmacher ◽  
Kathryn C. Racine ◽  
Andrew P. Neilson
Keyword(s):  
Chlorogenic Acid ◽  
Gallic Acid ◽  
High Throughput ◽  
Anaerobic Fermentation ◽  
Inhibitory Effect ◽  
Healthy Human ◽  
High Throughput Method ◽  
Lyase Activity ◽  
Inhibitory Potential ◽  
Potential Maximum

Choline is metabolized by the gut microbiota into trimethylamine (TMA), the precursor of pro-atherosclerotic molecule trimethylamine N-oxide (TMAO). A reduction in TMA formation has shown cardioprotective effects, and some phytochemicals may reduce TMA formation. This study aimed to develop an optimized, high-throughput anaerobic fermentation methodology to study the inhibition of choline microbial metabolism into TMA by phenolic compounds with healthy human fecal starter. Optimal fermentation conditions were: 20% fecal slurry (1:10 in PBS), 100 µM choline, and 12 h fermentation. Additionally, 10 mM of 3,3-dimethyl-1-butanol (DMB) was defined as a positive TMA production inhibitor, achieving a ~50% reduction in TMA production. Gallic acid and chlorogenic acid reported higher TMA inhibitory potential (maximum of 80–90% TMA production inhibition), with IC50 around 5 mM. Neither DMB nor gallic acid or chlorogenic acid reduced TMA production through cytotoxic effects, indicating mechanisms such as altered TMA-lyase activity or expression.

scholarly journals Development of a Novel Label-Free and High-Throughput Arginase-1 Assay Using Self-Assembled Monolayer Desorption Ionization Mass Spectrometry

2021 ◽  
pp. 247255522110006
Author(s):  
Michael D. Scholle ◽  
Zachary A. Gurard-Levin
Keyword(s):  
Mass Spectrometry ◽  
Drug Discovery ◽  
High Throughput ◽  
Ionization Mass Spectrometry ◽  
Ionization Mass ◽  
Label Free ◽  
Desorption Ionization ◽  
Arginase 1 ◽  
Self Assembled ◽  
High Throughput Assay

Arginase-1, an enzyme that catalyzes the reaction of L-arginine to L-ornithine, is implicated in the tumor immune response and represents an interesting therapeutic target in immuno-oncology. Initiating arginase drug discovery efforts remains a challenge due to a lack of suitable high-throughput assay methodologies. This report describes the combination of self-assembled monolayers and matrix-assisted laser desorption ionization mass spectrometry to enable the first label-free and high-throughput assay for arginase activity. The assay was optimized for kinetically balanced conditions and miniaturized, while achieving a robust assay (Z-factor > 0.8) and a significant assay window [signal-to-background ratio > 20] relative to fluorescent approaches. To validate the assay, the inhibition of the reference compound nor-NOHA (Nω-hydroxy-nor-L-arginine) was evaluated, and the IC50 measured to be in line with reported results (IC50 = 180 nM). The assay was then used to complete a screen of 175,000 compounds, demonstrating the high-throughput capacity of the approach. The label-free format also eliminates opportunities for false-positive results due to interference from library compounds and optical readouts. The assay methodology described here enables new opportunities for drug discovery for arginase and, due to the assay flexibility, can be more broadly applicable for measuring other amino acid–metabolizing enzymes.

A high-throughput assay for HIV-1 integrase 3′-processing activity using time-resolved fluorescence

2012 ◽  
Vol 184 (1-2) ◽  
pp. 34-40 ◽  
Author(s):  
Ying-Shan Han ◽  
Peter Quashie ◽  
Thibault Mesplede ◽  
Hongtao Xu ◽  
Kevork Mekhssian ◽  
...  
Keyword(s):  
High Throughput ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Processing Activity ◽  
High Throughput Assay ◽  
Hiv 1
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