The interaction of GTP with initiation factor eIF-2 in different complexes was studied by affinity labeling using a derivative of [3H]GTP carrying a photoreactive group in the alpha-phosphate moiety. In the binary complex [eIF-2.GTP analogue], in the ternary complex [eIF-2.GTP analogue.Met-tRNAf] as well as in the eIF-2. eIF-2B complex the alpha-subunit of eIF-2 was found to be specifically labeled. GTP is concluded to interact during polypeptide chain initiation with the alpha-subunit of eIF-2 at least by its alpha-phosphate group.
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J Control Release
January 2025
Molecular Imaging Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address:
B7-H3, an immunomodulatory protein overexpressed in many cancers, is associated with tumor aggressiveness and poor prognosis, making it a crucial target for imaging to elucidate its role in cancer progression and guide therapeutic interventions. This study employed PET imaging to investigate the in vivo delivery and pharmacokinetics of two anti-B7-H3 antibodies, Ab-1 and Ab-2, in mouse xenograft models with varying B7-H3 expression levels. The antibodies were radiolabeled with [Zr]Zr and evaluated through PET imaging, biodistribution studies, and in vitro assays to assess binding, tumor uptake, and retention.
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January 2025
The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
CD28 is a costimulatory receptor that provides the second signal necessary for T-cell activation and is associated with diseases, including rheumatoid arthritis, asthma, and cancer. Targeting CD28 is crucial for both functional bioanalysis and therapeutic development. Molecular probes, particularly fluorescent probes, can enhance our understanding of CD28's cellular roles.
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January 2025
National Institute of Standards and Technology, Material Measurement Laboratory, UNITED STATES OF AMERICA.
Antibody-based pharmaceuticals are the leading biologic drug platform (> $75B/year). Despite a wealth of information collected on them, there is still a lack of knowledge on their inter-domain structural distributions, which impedes innovation and development. To address this measurement gap, we have developed a new methodology to derive biomolecular structure ensembles from distance distribution measurements via a library of tagged proteins bound to an unlabeled and otherwise unmodified target biologic.
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September 2024
Molecular and Cellular Biochemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan.
Single-molecule imaging provides information on diffusion dynamics, oligomerization, and protein-protein interactions in living cells. To simultaneously monitor different types of proteins at the single-molecule level, orthogonal fluorescent labeling methods with different photostable dyes are required. G-protein-coupled receptors (GPCRs), a major class of drug targets, are prototypical membrane receptors that have been studied using single-molecule imaging techniques.
View Article and Find Full Text PDFChembiochem
January 2025
University of Konstanz, Department of Chemistry, Universitaetsstrasse 10, 78457, Konstanz, GERMANY.
The ubiquitin (Ub) ligase E6AP, which is encoded by the UBE3A gene, has been associated with several human diseases including cervical cancer and Angelman syndrome, a neurodevelopmental disorder. Yet, our knowledge about disease-relevant substrates of E6AP is still limited. The formation of a thioester complex between Ub and the catalytic Cys residue of E6AP represents an essential intermediate step in E6AP-mediated ubiquitination.
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