Fc receptors are involved in a variety of physiologically and disease-relevant responses. Among them, FcγRIIA (CD32a) is known for its activating functions in pathogen recognition and platelet biology, and, as potential marker of T lymphocytes latently infected with HIV-1. The latter has not been without controversy due to technical challenges complicated by T-B cell conjugates and trogocytosis as well as a lack of antibodies distinguishing between the closely related isoforms of FcγRII. To generate high-affinity binders specific for FcγRIIA, libraries of designed ankyrin repeat proteins (DARPins) were screened for binding to its extracellular domains by ribosomal display. Counterselection against FcγRIIB eliminated binders cross-reacting with both isoforms. The identified DARPins bound FcγRIIA with no detectable binding for FcγRIIB. Their affinities for FcγRIIA were in the low nanomolar range and could be enhanced by cleavage of the His-tag and dimerization. Interestingly, complex formation between DARPin and FcγRIIA followed a two-state reaction model, and discrimination from FcγRIIB was based on a single amino acid residue. In flow cytometry, DARPin F11 detected FcγRIIA cells even when they made up less than 1% of the cell population. Image stream analysis of primary human blood cells confirmed that F11 caused dim but reliable cell surface staining of a small subpopulation of T lymphocytes. When incubated with platelets, F11 inhibited their aggregation equally efficient as antibodies unable to discriminate between both FcγRII isoforms. The selected DARPins are unique novel tools for platelet aggregation studies as well as the role of FcγRIIA for the latent HIV-1 reservoir.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10209026 | PMC |
http://dx.doi.org/10.1016/j.jbc.2023.104743 | DOI Listing |
Chemistry
December 2024
Osaka University, Graduate School of Pharmaceutical Sciences, 1-6, Yamada-oka, 565-0871, Osaka, JAPAN.
Deuterated molecules are of growing interest because of the specific characteristics of deuterium, such as stronger C-D bonds being stronger than C-H bonds. Polyethylene glycols (PEGs) are widely utilized in scientific fields (e.g.
View Article and Find Full Text PDFChembiochem
December 2024
Illinois State University, Chemistry, UNITED STATES OF AMERICA.
Protein degradation is pivotal for all biochemical aspects of cellular function. In mammalian cells, protein degradation is mediated mainly by the ubiquitin proteasome system (UPS) and the autophagic-lysosomal system (ALS). Over the last two decades, different types of targeted protein degradation approaches have been developed including proteolysis targeting chimeras (PROTACs) and lysosome targeting chimeras (LYTACs), which employ the UPS to degrade intracellular proteins and the ALS to degrade extracellular and membrane proteins respectively.
View Article and Find Full Text PDFGenes Genomics
December 2024
School of Chemical Engineering and Biomolecular Engineering, Pusan National University, Busan, 46241, Republic of Korea.
Background: The genomes of publicly available electroactive Pseudomonas aeruginosa strains are currently limited to in-silico analyses. This study analyzed the electroactive Pseudomonas aeruginosa PBH03 genome using comparative in-silico studies for biotechnological applications.
Objective: Comparative in-silico and experimental analyses were conducted to identify the novel traits of P.
J Phys Chem B
December 2024
Centro de Química Estrutural, Institute of Molecular Sciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
This study addresses a critical gap in the existing literature on carbon dioxide and ionic liquid (IL) mixtures, where fragmented and incomplete data, particularly for flow properties, hinder practical applications. Therefore, this work aimed to establish a robust and efficient method for predicting the density of the CO-IL mixtures across diverse operating conditions and IL families using novel validation techniques. Both linear and symbolic regression models provided relevant insights but failed to accurately capture the IL-CO interactions in a mixture that determine the molar volume of CO at infinite dilution when solubilized by a given IL.
View Article and Find Full Text PDFUnlabelled: The corticospinal tract (CST) facilitates skilled, precise movements, which necessitates that subcerebral projection neurons (SCPN) establish segmentally specific connectivity with brainstem and spinal circuits. Developmental molecular delineation enables prospective identification of corticospinal neurons (CSN) projecting to thoraco-lumbar spinal segments; however, it remains unclear whether other SCPN subpopulations in developing sensorimotor cortex can be prospectively identified in this manner. Such molecular tools could enable investigations of SCPN circuitry with precision and specificity.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!