scholarly journals Chaperones drive in vitro evolution of uracil glycosylase towards misfolded states

2021 ◽  
Author(s):  
Oran Melanker ◽  
Pierre A Goloubinoff ◽  
Gideon Schreiber
Keyword(s):  
Protein Interactions ◽  
Surface Display ◽  
Yeast Surface Display ◽  
General Context ◽  
Short Time Scale ◽  
In Vitro Evolution ◽  
Protein Mimics ◽  
Random Library ◽  
Specific Outcome

Evolution is driven by random mutations, whose fitness outcome is tested over time. In vitro evolution of a library of a randomly mutated protein mimics this process, however, on a short time scale, driven by a specific outcome (such as binding to a bait). Here, we used directed in vitro evolution to investigate the role of molecular chaperones in curbing promiscuity in favor of specificity of protein-protein interactions. Using yeast surface display, we generated a random library of the E. coli protein Uracil glycosylase (UNG), and selected it against various baits. Those included the purified chaperones GroEL, DnaK+DnaJ+ATP, or total protein extracts from WT or delta DnaK+DnaJ cells. We show that in-vitro evolution differs from natural evolution in cells, both physically and thermodynamically. We found that chaperones, whether purified or as part of the protein extract, select for and thus enrich uracil glycosylase (UNG) misfolded species during this in vitro evolution process. In a more general context, our results show that chaperones purge promiscuous misfolded clones from the system, and thereby avoiding their detrimental effects, such as forming wrong interactions with other macromolecules, including proteins, which can harm proteostasis.

scholarly journals Synthetic repertoires derived from convalescent COVID-19 patients enable discovery of SARS-CoV-2 neutralizing antibodies and a novel quaternary binding modality

2021 ◽  
Author(s):  
Jimmy D Gollihar ◽  
Jason S McLellan ◽  
Daniel R Boutz ◽  
Jule Goike ◽  
Andrew Horton ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Surface Display ◽  
Functional Characterization ◽  
Yeast Surface Display ◽  
Spike Protein ◽  
Emerging Pathogens ◽  
Effective Interventions ◽  
Yeast Surface

The ongoing evolution of SARS-CoV-2 into more easily transmissible and infectious variants has sparked concern over the continued effectiveness of existing therapeutic antibodies and vaccines. Hence, together with increased genomic surveillance, methods to rapidly develop and assess effective interventions are critically needed. Here we report the discovery of SARS-CoV-2 neutralizing antibodies isolated from COVID-19 patients using a high-throughput platform. Antibodies were identified from unpaired donor B-cell and serum repertoires using yeast surface display, proteomics, and public light chain screening. Cryo-EM and functional characterization of the antibodies identified N3-1, an antibody that binds avidly (Kd,app = 68 pM) to the receptor binding domain (RBD) of the spike protein and robustly neutralizes the virus in vitro. This antibody likely binds all three RBDs of the trimeric spike protein with a single IgG. Importantly, N3-1 equivalently binds spike proteins from emerging SARS-CoV-2 variants of concern, neutralizes UK variant B.1.1.7, and binds SARS-CoV spike with nanomolar affinity. Taken together, the strategies described herein will prove broadly applicable in interrogating adaptive immunity and developing rapid response biological countermeasures to emerging pathogens.

scholarly journals Rapid Affinity Maturation of Novel Anti-PD-L1 Antibodies by a Fast Drop of the Antigen Concentration and FACS Selection of Yeast Libraries

2019 ◽  
Vol 2019 ◽  
pp. 1-22 ◽  
Author(s):  
Biancamaria Cembrola ◽  
Valentino Ruzza ◽  
Fulvia Troise ◽  
Maria Luisa Esposito ◽  
Emanuele Sasso ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Surface Display ◽  
Affinity Maturation ◽  
Yeast Surface Display ◽  
Antigen Concentration ◽  
Selection Scheme ◽  
High Affinity ◽  
Novel Approach ◽  
Yeast Surface

The affinity engineering is a key step to increase the efficacy of therapeutic monoclonal antibodies and yeast surface display is the most widely used and powerful affinity maturation approach, achieving picomolar binding affinities. In this study, we provide an optimization of the yeast surface display methodology, applied to the generation of potentially therapeutic high affinity antibodies targeting the immune checkpoint PD-L1. In this approach, we coupled a 10-cycle error-prone mutagenesis of heavy chain complementarity determining region 3 of an anti‐PD-L1 scFv, previously identified by phage display, with high-throughput sequencing, to generate scFv-yeast libraries with high mutant frequency and diversity. In addition, we set up a novel, faster and effective selection scheme by fluorescence-activated cell sorting, based on a fast drop of the antigen concentration between the first and the last selection cycles, unlike the gradual decrease typical of current selection protocols. In this way we isolated 6 enriched mutated scFv-yeast clones overall, showing an affinity improvement for soluble PD-L1 protein compared to the parental scFv. As a proof of the potency of the novel approach, we confirmed that the antibodies converted from all the mutated scFvs retained the affinity improvement. Remarkably, the best PD-L1 binder among them also bound with a higher affinity to PD-L1 expressed in its native conformation on human-activated lymphocytes, and it was able to stimulate lymphocyte proliferation in vitro more efficiently than its parental antibody. This optimized technology, besides the identification of a new potential checkpoint inhibitor, provides a tool for the quick isolation of high affinity binders.

scholarly journals Affinity Maturation of Tacrolimus Antibody for Improved Immunoassay Performance

2008 ◽  
Vol 54 (6) ◽  
pp. 1008-1017 ◽  
Author(s):  
Robert W Siegel ◽  
Wade Baugher ◽  
Tanya Rahn ◽  
Susan Drengler ◽  
Joan Tyner
Keyword(s):  
Limit Of Detection ◽  
Recombinant Antibody ◽  
Surface Display ◽  
Dissociation Rate ◽  
Affinity Maturation ◽  
Antibody Engineering ◽  
Yeast Surface Display ◽  
Variable Heavy ◽  
Variable Light

Abstract Background: Organic solvents used for extraction of tacrolimus from whole blood samples lower the apparent affinity of the antibody used in a diagnostic immunoassay, thereby affecting the detection limit. Methods: We used in vitro recombinant antibody engineering to screen and isolate clones from diverse libraries with mutagenic complementarity regions (CDRs) from tacrolimus 1-60-46 hybridoma cell line, with improved binding to tacrolimus in the presence of 10% methanol organic solvent solution. Results: We isolated a number of clones with mutations in variable heavy (VH) CDR 2, variable light (VL) CDR 1, and VL CDR 3 with improved binding. Various combinatorial pairings constructed from these individual mutations contained >10-fold improvements in both the dissociation rate and overall equilibrium affinity constants. Selected clones produced as IgG have increased functional sensitivity, with a 3- to 6-fold reduction in the limit of detection relative to the parental tacrolimus 1-60-46 monoclonal antibody in the Architect® Tacrolimus immunodiagnostic assay. Conclusions: The recent advent of recombinant in vitro antibody display technologies in general, and yeast surface display in particular, allows the flexibility to engineer new or augment specific analytical characteristics, such as affinity, specificity, or stability, into previously isolated and otherwise desirable antibodies to enhance assay performance. These in vitro selections can also be performed under conditions meant to mimic the assay in which the reagent will ultimately be used, to increase the likelihood of successful assay development.

scholarly journals Development of High Affinity and High Specificity Inhibitors of Matrix Metalloproteinase 14 through Computational Design and Directed Evolution

2017 ◽  
Vol 292 (8) ◽  
pp. 3481-3495 ◽  
Author(s):  
Valeria Arkadash ◽  
Gal Yosef ◽  
Jason Shirian ◽  
Itay Cohen ◽  
Yuval Horev ◽  
...  
Keyword(s):  
Directed Evolution ◽  
Surface Display ◽  
High Specificity ◽  
Computational Design ◽  
Computational Method ◽  
Yeast Surface Display ◽  
Mmp Inhibitor ◽  
Starting Point ◽  
Yeast Surface

Degradation of the extracellular matrices in the human body is controlled by matrix metalloproteinases (MMPs), a family of more than 20 homologous enzymes. Imbalance in MMP activity can result in many diseases, such as arthritis, cardiovascular diseases, neurological disorders, fibrosis, and cancers. Thus, MMPs present attractive targets for drug design and have been a focus for inhibitor design for as long as 3 decades. Yet, to date, all MMP inhibitors have failed in clinical trials because of their broad activity against numerous MMP family members and the serious side effects of the proposed treatment. In this study, we integrated a computational method and a yeast surface display technique to obtain highly specific inhibitors of MMP-14 by modifying the natural non-specific broad MMP inhibitor protein N-TIMP2 to interact optimally with MMP-14. We identified an N-TIMP2 mutant, with five mutations in its interface, that has an MMP-14 inhibition constant (Ki) of 0.9 pm, the strongest MMP-14 inhibitor reported so far. Compared with wild-type N-TIMP2, this variant displays ∼900-fold improved affinity toward MMP-14 and up to 16,000-fold greater specificity toward MMP-14 relative to other MMPs. In an in vitro and cell-based model of MMP-dependent breast cancer cellular invasiveness, this N-TIMP2 mutant acted as a functional inhibitor. Thus, our study demonstrates the enormous potential of a combined computational/directed evolution approach to protein engineering. Furthermore, it offers fundamental clues into the molecular basis of MMP regulation by N-TIMP2 and identifies a promising MMP-14 inhibitor as a starting point for the development of protein-based anticancer therapeutics.

scholarly journals Generating quantitative binding landscapes through fractional binding selections, deep sequencing and data normalization

2019 ◽  
Author(s):  
Michael Heyne ◽  
Niv Papo ◽  
Julia Shifman
Keyword(s):  
Free Energy ◽  
Protein Interactions ◽  
Binding Free Energy ◽  
Surface Display ◽  
Yeast Surface Display ◽  
Protein Protein Interactions ◽  
Protein Mutants ◽  
Display Technology ◽  
Data Points ◽  
Affinity Interaction

AbstractQuantifying the effects of various mutations on binding free energy is crucial for understanding the evolution of protein-protein interactions and would greatly facilitate protein engineering studies. Yet, measuring changes in binding free energy (ΔΔGbind) remains a tedious task that requires expression of each mutant, its purification, and affinity measurements. We developed a new approach that allows us to quantify ΔΔGbindfor thousands of protein mutants in one experiment. Our protocol combines protein randomization, Yeast Surface Display technology, Next Generation Sequencing, and a few experimental ΔΔGbinddata points on purified proteins to generate ΔΔGbindvalues for the remaining numerous mutants of the same protein complex. Using this methodology, we comprehensively map the single-mutant binding landscape of one of the highest-affinity interaction between BPTI and Bovine Trypsin. We show that ΔΔGbindfor this interaction could be quantified with high accuracy over the range of 12 kcal/mol displayed by various BPTI single mutants.

scholarly journals Yeast surface display of full-length human microtubule-associated protein tau

2019 ◽  
Author(s):  
Shiyao Wang ◽  
Yong Ku Cho
Keyword(s):  
Conformational Change ◽  
Protein Interactions ◽  
Surface Display ◽  
Full Length ◽  
Adult Brain ◽  
Yeast Surface Display ◽  
Post Translational Modification ◽  
Protein Tau ◽  
Microtubule Associated Protein Tau ◽  
Intrinsically Disordered

AbstractMicrotubule-associated protein tau is an intrinsically-disordered, highly soluble protein found primarily in neurons. Under normal conditions, tau regulates the stability of axonal microtubules and intracellular vesicle transport. However, in patients of neurodegeneration such as Alzheimer’s disease (AD), tau forms neurofibrillary deposits, which correlates well with the disease progression. Identifying molecular signatures in tau, such as post-translational modification, truncation, and conformational change has great potential to detect earliest signs of neurodegeneration, and develop therapeutic strategies. Here we show that full-length human tau, including the longest isoform found in the adult brain can be robustly displayed on the surface of yeastSaccharomyces cerevisiae. Yeast-displayed tau binds to anti-tau antibodies that cover epitopes ranging from the N-terminus to the 4R repeat region. Unlike tau expressed in the yeast cytosol, surface-displayed tau was not phosphorylated at sites found in AD patients (probed by antibodies AT8, AT270, AT180, PHF-1). However, yeast-displayed tau showed clear binding to paired helical filament (PHF) tau conformation-specific antibodies Alz-50, MC-1, and Tau-2. Although the tau possessed a conformation found in PHFs, oligomerization or aggregation into larger filaments were undetected. Taken together, yeast-displayed tau enables robust measurement of protein interactions, and is of particular interest for characterizing conformational change.

scholarly journals Neutralizing antibodies targeting the SARS-CoV-2 receptor binding domain isolated from a naïve human antibody library

2021 ◽  
Author(s):  
Benjamin Nikola Bell ◽  
Abigail E. Powell ◽  
Carlos Rodriguez ◽  
Jennifer R Cochran ◽  
Peter S. Kim
Keyword(s):  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
In Vitro Selection ◽  
Surface Display ◽  
Binding Domain ◽  
Yeast Surface Display ◽  
Surface Glycoprotein ◽  
Human Antibody ◽  
Receptor Binding Domain

Infection with SARS-CoV-2 elicits robust antibody responses in some patients, with a majority of the response directed at the receptor binding domain (RBD) of the spike surface glycoprotein. Remarkably, many patient-derived antibodies that potently inhibit viral infection harbor few to no mutations from the germline, suggesting that naive antibody libraries are a viable means for discovery of novel SARS-CoV-2 neutralizing antibodies. Here, we used a yeast surface-display library of human naive antibodies to isolate and characterize three novel neutralizing antibodies that target the RBD: one that blocks interaction with angiotensin-converting enzyme 2 (ACE2), the human receptor for SARS-CoV-2, and two that target other epitopes on the RBD. These three antibodies neutralized SARS-CoV-2 spike-pseudotyped lentivirus with IC50 values as low as 60 ng/mL in vitro. Using a biolayer interferometry-based binding competition assay, we determined that these antibodies have distinct but overlapping epitopes with antibodies elicited during natural COVID-19 infection. Taken together, these analyses highlight how in vitro selection of naive antibodies can mimic the humoral response in vivo, yielding neutralizing antibodies and various epitopes that can be effectively targeted on the SARS-CoV-2 RBD.

scholarly journals Quantitative yeast-yeast two hybrid for discovery and binding affinity estimation of protein-protein interactions

2020 ◽  
Author(s):  
Kaitlyn Bacon ◽  
Abigail Blain ◽  
John Bowen ◽  
Matthew Burroughs ◽  
Nikki McArthur ◽  
...  
Keyword(s):  
Binding Affinity ◽  
Protein Interactions ◽  
Quantitative Estimation ◽  
Surface Display ◽  
Combinatorial Libraries ◽  
Yeast Surface Display ◽  
Binding Affinities ◽  
Protein Protein Interactions ◽  
Yeast Two Hybrid ◽  
Two Hybrid

AbstractQuantifying the binding affinity of protein-protein interactions is important for elucidating connections within biochemical signaling pathways, as well as characterization of binding proteins isolated from combinatorial libraries. We describe a quantitative yeast-yeast two hybrid (qYY2H) system that not only enables discovery of specific protein-protein interactions, but also efficient, quantitative estimation of their binding affinities (KD). In qYY2H, the bait and prey proteins are expressed as yeast cell surface fusions using yeast surface display. We developed a semi-empirical framework for estimating the KD of monovalent bait-prey interactions, using measurements of the apparent KD of yeast-yeast binding, which is mediated by multivalent interactions between yeast-displayed bait and prey. Using qYY2H, we identified interaction partners of SMAD3 and the tandem WW domains of YAP from a cDNA library and characterized their binding affinities. Finally, we showed that qYY2H could also quantitatively evaluate binding interactions mediated by post-translational modifications on the bait protein.

scholarly journals Yeast Surface Display System: Strategies for Improvement and Biotechnological Applications

2022 ◽  
Vol 9 ◽  
Author(s):  
Karla V. Teymennet-Ramírez ◽  
Fernando Martínez-Morales ◽  
María R. Trejo-Hernández
Keyword(s):  
Protein Interactions ◽  
Genetic Manipulation ◽  
Surface Display ◽  
Yeast Surface Display ◽  
Yeast Cells ◽  
Biotechnological Applications ◽  
Protein Protein Interactions ◽  
Post Translational Modifications ◽  
Yeast Surface ◽  
Antibody Design

Yeast surface display (YSD) is a “whole-cell” platform used for the heterologous expression of proteins immobilized on the yeast’s cell surface. YSD combines the advantages eukaryotic systems offer such as post-translational modifications, correct folding and glycosylation of proteins, with ease of cell culturing and genetic manipulation, and allows of protein immobilization and recovery. Additionally, proteins displayed on the surface of yeast cells may show enhanced stability against changes in temperature, pH, organic solvents, and proteases. This platform has been used to study protein-protein interactions, antibody design and protein engineering. Other applications for YSD include library screening, whole-proteome studies, bioremediation, vaccine and antibiotics development, production of biosensors, ethanol production and biocatalysis. YSD is a promising technology that is not yet optimized for biotechnological applications. This mini review is focused on recent strategies to improve the efficiency and selection of displayed proteins. YSD is presented as a cutting-edge technology for the vectorial expression of proteins and peptides. Finally, recent biotechnological applications are summarized. The different approaches described herein could allow for a better strategy cascade for increasing protein/peptide interaction and production.

Sign in / Sign up

Export Citation Format

Share Document