Publications by authors named "Alex Pelletier"

The continuous improvement of expression platforms is necessary to respond to the increasing demand for recombinant proteins that are required to carry out structural or functional studies as well as for their characterization as biotherapeutics. While transient gene expression (TGE) in mammalian cells constitutes a rapid and well-established approach, non-clonal stably transfected cells, or "pools," represent another option, which is especially attractive when recurring productions of the same protein are required. From a culture volume of just a few liters, stable pools can provide hundreds of milligrams to gram quantities of high-quality secreted recombinant proteins.

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Surface plasmon resonance (SPR)-based biosensing enables the characterization of protein-protein interactions. Several SPR-based approaches have been designed to evaluate the binding mechanism between the angiotensin-converting enzyme 2 (ACE2) receptor and the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein leading to a large range of kinetic and thermodynamic constants. This chapter describes a robust SPR assay based on the K5/E5 coiled-coil capture strategy that reduces artifacts.

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Article Synopsis
  • SARS-CoV-2 subunit vaccines focus on using spike protein antigens fused with trimerization sequences to imitate the virus's surface structure.
  • Researchers have produced various spike variants in CHO cells, discovering two distinct trimer forms through analytical techniques.
  • The study shows that temperature and pH can influence the structures of these trimer forms, potentially affecting their effectiveness as vaccine components.
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Immersive virtual reality (VR) technologies can produce powerful illusions of being in another place or inhabiting another body, and theories of presence and embodiment provide valuable guidance to designers of VR applications that use these illusions to "take us elsewhere." However, an increasingly common design goal for VR experiences is to develop a deeper awareness of the internal landscape of one's own body (i.e.

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Article Synopsis
  • Protein expression from stably transfected CHO clones is traditionally time-consuming for making therapeutic proteins, but newer methods like stable pools have improved significantly in speed and productivity.
  • Researchers have found that stable pools can produce high-quality SARS-CoV-2 spike proteins comparable to traditional clones in just weeks, rather than months.
  • The study suggests updating regulatory guidelines to allow the use of CHO pools for rapid development of clinical trial materials, especially important during urgent situations like pandemics.
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Several key mutations in the Spike protein receptor binding domain (RBD) have been identified to influence its affinity for the human Angiotensin-Converting Enzyme 2 (ACE2). Here, we perform a comparative study of the ACE2 binding to the wild type (Wuhan) RBD and some of its variants: Alpha B.1.

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Human carbonic anhydrase (hCAIX), an extracellular enzyme that catalyzes the reversible hydration of CO, is often overexpressed in solid tumors. This enzyme is instrumental in maintaining the survival of cancer cells in a hypoxic and acidic tumor microenvironment. Absent in most normal tissues, hCAIX is a promising therapeutic target for detection and treatment of solid tumors.

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The architectural complexity and heterogeneity of the tumor microenvironment (TME) remains a substantial obstacle in the successful treatment of cancer. Hypoxia, caused by insufficient oxygen supply, and acidosis, resulting from the expulsion of acidic metabolites, are prominent features of the TME. To mitigate the consequences of the hostile TME, cancer cells metabolically rewire themselves and express a series of specific transporters and enzymes instrumental to this adaptation.

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Background: Gene fusions often occur in cancer cells and in some cases are the main driver of oncogenesis. Correct identification of oncogenic gene fusions thus has implications for targeted cancer therapy. Recognition of this potential has led to the development of a myriad of sequencing-based fusion detection tools.

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Recently, a new class of HIV reverse transcriptase (HIV-RT) inhibitors has been reported. The novel mechanism of inhibition by this class involves competitive binding to the active site of the RT enzyme and has been termed Nucleotide-Competing Reverse Transcriptase Inhibitors (NcRTIs). In this publication we describe the optimization of a novel benzofurano[3,2-d]pyrimidin-2-one series of NcRTIs.

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A HTS screen led to the identification of a benzofurano[3,2-d]pyrimidin-2-one core structure which upon further optimization resulted in 1 as a potent HIV-1 nucleotide competing reverse transcriptase inhibitor (NcRTI). Investigation of the SAR at N-1 allowed significant improvements in potency and when combined with the incorporation of heterocycles at C-8 resulted in potent analogues not requiring a basic amine to achieve antiviral activity. Additional modifications at N-1 resulted in 33 which demonstrated excellent antiviral potency and improved physicochemical properties.

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Human papillomavirus (HPV) DNA replication is initiated by recruitment of the E1 helicase by the E2 protein to the viral origin. Screening of our corporate compound collection with an assay measuring the cooperative binding of E1 and E2 to the origin identified a class of small molecule inhibitors of the protein interaction between E1 and E2. Isothermal titration calorimetry and changes in protein fluorescence showed that the inhibitors bind to the transactivation domain of E2, the region that interacts with E1.

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Integrons can insert and excise antibiotic resistance genes on plasmids in bacteria by site-specific recombination. Class 1 integrons code for an integrase, IntI1 (337 amino acids in length), and are generally borne on elements derived from Tn5090, such as that found in the central part of Tn21. A second class of integron is found on transposon Tn7 and its relatives.

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