scholarly journals A high-throughput, automated, cell-free expression and screening platform for antibody discovery

2021 ◽  
Author(s):  
Andrew C Hunt ◽  
Bastian Vogeli ◽  
Weston K. Kightlinger ◽  
Danielle J. Yoesep ◽  
Antje Kruger ◽  
...  

Antibody discovery is bottlenecked by the individual expression and evaluation of antigen- specific hits. Here, we address this gap by developing an automated workflow combining cell-free DNA template generation, protein synthesis, and high-throughput binding measurements of antibody fragments in a process that takes hours rather than weeks. We apply this workflow to 119 published SARS-CoV-2 neutralizing antibodies and demonstrate rapid identification of the most potent antibody candidates.

2021 ◽  
Author(s):  
Ross P. Thomas ◽  
Rachel E. Heap ◽  
Francesca Zappacosta ◽  
Emma K. Grant ◽  
Peter Pogany ◽  
...  

<p>Methods for rapid identification of chemical tools are essential for the validation of emerging targets and to provide medicinal chemistry starting points for the development of <a>new medicines. Here, we report a screening platform that combines ‘direct-to-biology’ high-throughput chemistry (D2B-HTC) with photoreactive covalent fragments. The platform enabled the rapid synthesis of >1000 PhotoAffinity Bits (HTC-PhABits) in 384-well plates. Screening the HTC-PhABit library with </a>carbonic anhydrase I (CAI) afforded 7 hits (0.7% hit rate), which were found to covalently crosslink in the Zn<sup>2+</sup> binding pocket. A powerful advantage of the D2B-HTC screening platform is the ability to rapidly perform iterative design-make-test cycles, accelerating the development and optimisation of chemical tools and medicinal chemistry starting points with little investment of resource.</p>


2021 ◽  
Author(s):  
Andrea R Shiakolas ◽  
Nicole Johnson ◽  
Kevin J Kramer ◽  
Naveenchandra Suryadevara ◽  
Daniel Wrapp ◽  
...  

SARS-CoV-2 therapeutic antibody discovery efforts have met with notable success but have been associated with a generally inefficient process, requiring the production and characterization of exceptionally large numbers of candidates for the identification of a small set of leads. Here, we show that incorporating antibody-ligand blocking as part of LIBRA-seq, the high-throughput sequencing platform for antibody discovery, results in efficient identification of ultra-potent neutralizing antibodies against SARS-CoV-2. LIBRA-seq with ligand blocking is a general platform for functional antibody discovery targeting the disruption of antigen-ligand interactions.


2021 ◽  
Author(s):  
Ross P. Thomas ◽  
Rachel E. Heap ◽  
Francesca Zappacosta ◽  
Emma K. Grant ◽  
Peter Pogany ◽  
...  

<p>Methods for rapid identification of chemical tools are essential for the validation of emerging targets and to provide medicinal chemistry starting points for the development of <a>new medicines. Here, we report a screening platform that combines ‘direct-to-biology’ high-throughput chemistry (D2B-HTC) with photoreactive covalent fragments. The platform enabled the rapid synthesis of >1000 PhotoAffinity Bits (HTC-PhABits) in 384-well plates. Screening the HTC-PhABit library with </a>carbonic anhydrase I (CAI) afforded 7 hits (0.7% hit rate), which were found to covalently crosslink in the Zn<sup>2+</sup> binding pocket. A powerful advantage of the D2B-HTC screening platform is the ability to rapidly perform iterative design-make-test cycles, accelerating the development and optimisation of chemical tools and medicinal chemistry starting points with little investment of resource.</p>


2021 ◽  
Author(s):  
Jong-Won Lee ◽  
Hyeongmin Seo ◽  
Caleb Young ◽  
Cong T Trinh

Alcohol acyltransferases (AATs) enables microbial biosynthesis of a large space of esters by condensing an alcohol and an acyl CoA. However, substrate promiscuity of AATs prevents microbial biosynthesis of designer esters with high selectivity. Here, we developed a high-throughput microbial screening platform that facilitates rapid identification of AATs for designer ester biosynthesis. First, we established a microplate-based culturing technique with in situ fermentation and extraction of esters. We validated its capability in rapid profiling of the alcohol substrate specificity of 20 chloramphenicol acetyltransferase variants derived from Staphylococcus aureus (CATSa) for microbial biosynthesis of acetate esters with various exogeneous alcohol supply. By coupling the microplate-based culturing technique with a previously established colorimetric assay, we developed a high-throughput microbial screening platform for AATs. We demonstrated that this platform could not only confirm CATSa F97W with enhanced isobutyl acetate synthesis but also identify three ATF1Sc (P348M, P348A, and P348S) variants, derived from Saccharomyces cerevisiae' s AAT and engineered by model-guided protein design, for enhanced butyl acetate production. We anticipate the high-throughput microbial screening platform is a useful tool to identify novel AATs that have important roles in nature and industrial biocatalysis for designer bioester production.


2006 ◽  
Vol 11 (3) ◽  
pp. 236-246 ◽  
Author(s):  
Laurence H. Lamarcq ◽  
Bradley J. Scherer ◽  
Michael L. Phelan ◽  
Nikolai N. Kalnine ◽  
Yen H. Nguyen ◽  
...  

A method for high-throughput cloning and analysis of short hairpin RNAs (shRNAs) is described. Using this approach, 464 shRNAs against 116 different genes were screened for knockdown efficacy, enabling rapid identification of effective shRNAs against 74 genes. Statistical analysis of the effects of various criteria on the activity of the shRNAs confirmed that some of the rules thought to govern small interfering RNA (siRNA) activity also apply to shRNAs. These include moderate GC content, absence of internal hairpins, and asymmetric thermal stability. However, the authors did not find strong support for positionspecific rules. In addition, analysis of the data suggests that not all genes are equally susceptible to RNAinterference (RNAi).


ACS Nano ◽  
2021 ◽  
Author(s):  
Sneh M. Toprani ◽  
Dimitrios Bitounis ◽  
Qiansheng Huang ◽  
Nathalia Oliveira ◽  
Kee Woei Ng ◽  
...  

ACS Sensors ◽  
2020 ◽  
Author(s):  
Ke-Jia Wu ◽  
Chun Wu ◽  
Feng Chen ◽  
Sha-Sha Cheng ◽  
Dik-Lung Ma ◽  
...  

2016 ◽  
Vol 60 (10) ◽  
pp. 5995-6002 ◽  
Author(s):  
Kristin R. Baker ◽  
Bimal Jana ◽  
Henrik Franzyk ◽  
Luca Guardabassi

ABSTRACTThe envelope of Gram-negative bacteria constitutes an impenetrable barrier to numerous classes of antimicrobials. This intrinsic resistance, coupled with acquired multidrug resistance, has drastically limited the treatment options against Gram-negative pathogens. The aim of the present study was to develop and validate an assay for identifying compounds that increase envelope permeability, thereby conferring antimicrobial susceptibility by weakening of the cell envelope barrier in Gram-negative bacteria. A high-throughput whole-cell screening platform was developed to measureEscherichia colienvelope permeability to a β-galactosidase chromogenic substrate. The signal produced by cytoplasmic β-galactosidase-dependent cleavage of the chromogenic substrate was used to determine the degree of envelope permeabilization. The assay was optimized by using known envelope-permeabilizing compounds andE. coligene deletion mutants with impaired envelope integrity. As a proof of concept, a compound library comprising 36 peptides and 45 peptidomimetics was screened, leading to identification of two peptides that substantially increased envelope permeability. Compound 79 reduced significantly (from 8- to 125-fold) the MICs of erythromycin, fusidic acid, novobiocin and rifampin and displayed synergy (fractional inhibitory concentration index, <0.2) with these antibiotics by checkerboard assays in two genetically distinctE. colistrains, including the high-risk multidrug-resistant, CTX-M-15-producing sequence type 131 clone. Notably, in the presence of 0.25 μM of this peptide, both strains were susceptible to rifampin according to the resistance breakpoints (R> 0.5 μg/ml) for Gram-positive bacterial pathogens. The high-throughput screening platform developed in this study can be applied to accelerate the discovery of antimicrobial helper drug candidates and targets that enhance the delivery of existing antibiotics by impairing envelope integrity in Gram-negative bacteria.


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