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Mechanical forces play a vital role in biological processes at molecular and cellular levels, significantly impacting various diseases such as cancer, cardiovascular disease, and COVID-19. Recent advancements in dynamic force spectroscopy (DFS) techniques have enabled the application and measurement of forces and displacements with high resolutions, providing crucial insights into the mechanical pathways underlying these diseases. Among DFS techniques, the biomembrane force probe (BFP) stands out for its ability to measure bond kinetics and cellular mechanosensing with pico-newton and nano-meter resolutions. Here, a comprehensive overview of the classical BFP-DFS setup is presented and key advancements are emphasized, including the development of dual biomembrane force probe (dBFP) and fluorescence biomembrane force probe (fBFP). BFP-DFS allows us to investigate dynamic bond behaviors on living cells and significantly enhances the understanding of specific ligand-receptor axes mediated cell mechanosensing. The contributions of BFP-DFS to the fields of cancer biology, thrombosis, and inflammation are delved into, exploring its potential to elucidate novel therapeutic discoveries. Furthermore, future BFP upgrades aimed at improving output and feasibility are anticipated, emphasizing its growing importance in the field of cell mechanobiology. Although BFP-DFS remains a niche research modality, its impact on the expanding field of cell mechanobiology is immense. [ABSTRACT FROM AUTHOR]

Detergents have been major contributors to membrane‐protein structural study for decades. However, membrane proteins solubilized in conventional detergents tend to aggregate or denature over time. Stability of large eukaryotic membrane proteins with complex structures tends to be particularly poor, necessitating development of novel detergents with improved properties. Here, we prepared a novel class of detergents, designated 3,4‐bis(hydroxymethyl)hexane‐1,6‐diol‐based maltosides (HDMs). When tested on three membrane proteins, including two G‐protein‐coupled receptors (GPCRs), the new detergents displayed significantly better behaviors compared with DDM. Moreover, the HDMs were superior or comparable to LMNG, an amphiphile widely used for GPCR structural study. An optimal balance of detergent rigidity vs. flexibility of the HDMs is likely responsible for their favorable behaviors toward membrane‐protein stability. Thus, the current study not only introduces the HDMs, with significant potential for membrane‐protein structural study, but also suggests a useful guideline for designing novel detergents for membrane‐protein research. [ABSTRACT FROM AUTHOR]

The μ‐opioid receptor (μOR) is the major target for opioid analgesics. Activation of μOR initiates signaling through G protein pathways as well as through β‐arrestin recruitment. μOR agonists that are biased towards G protein signaling pathways demonstrate diminished side effects. PZM21, discovered by computational docking, is a G protein biased μOR agonist. Here we report the cryoEM structure of PZM21 bound μOR in complex with Gi protein. Structure‐based evolution led to multiple PZM21 analogs with more pronounced Gi protein bias and increased lipophilicity to improve CNS penetration. Among them, FH210 shows extremely low potency and efficacy for arrestin recruitment. We further determined the cryoEM structure of FH210 bound to μOR in complex with Gi protein and confirmed its expected binding pose. The structural and pharmacological studies reveal a potential mechanism to reduce β‐arrestin recruitment by the μOR, and hold promise for developing next‐generation analgesics with fewer adverse effects. [ABSTRACT FROM AUTHOR]

Der μ‐Opioidrezeptor (μOR) ist das Haupt‐Angriffsziel für opioide Analgetika. Die Aktivierung des μORs initiiert die Signaltransduktion über G‐Protein‐vermittelte Wege und durch β‐Arrestin‐Rekrutierung. μOR‐Agonisten, die bevorzugt die G‐Protein‐vermittelte Signalübertragung aktivieren, weisen deutlich geringere Nebenwirkungen auf. Der Wirkstoff PZM21, welcher durch computergestütztes Docking entdeckt wurde, ist ein solcher funktionell‐selektiver Agonist (biased agonist) des μORs. In dieser Publikation stellen wir die Kryoelektronenmikroskopie‐Struktur (Cryo‐EM‐Struktur) des PZM21 gebundenen μOR im Komplex mit einem Gi Protein vor. Strukturbasiertes Wirkstoffdesign brachte eine Vielzahl an PZM21‐Analoga hervor, die einerseits eine noch deutlichere Gi‐Bevorzugung und andererseits, durch ihre höhere Lipophile, eine verbesserte ZNS‐Gängigkeit aufweisen. Darunter zeigt FH210 eine sehr geringe Wirkstärke bei der Arrestin‐Rekrutierung. Wir haben außerdem die Kryo‐EM‐Struktur von FH210, das an den μOR im Komplex mit dem Gi‐Protein gebunden ist, bestimmt und die erwartete Bindungsposition bestätigt. Die strukturellen und pharmakologischen Studien offenbaren einen potenziellen Mechanismus zur Verringerung der β‐Arrestin‐Rekrutierung durch den μOR und versprechen die Entwicklung von Analgetika der nächsten Generation mit weniger Nebenwirkungen. [ABSTRACT FROM AUTHOR]

Membrane proteins are of biological and pharmaceutical significance. However, their structural study is extremely challenging mainly due to the fact that only a small number of chemical tools are suitable for stabilizing membrane proteins in solution. Detergents are widely used in membrane protein study, but conventional detergents are generally poor at stabilizing challenging membrane proteins such as G protein‐coupled receptors and protein complexes. In the current study, we prepared tandem triazine‐based maltosides (TZMs) with two amphiphilic triazine units connected by different diamine linkers, hydrazine (TZM−Hs) and 1,2‐ethylenediamine (TZM−Es). These TZMs were consistently superior to a gold standard detergent (DDM) in terms of stabilizing a few membrane proteins. In addition, the TZM−Es containing a long linker showed more general protein stabilization efficacy with multiple membrane proteins than the TZM−Hs containing a short linker. This result indicates that introduction of the flexible1,2‐ethylenediamine linker between two rigid triazine rings enables the TZM−Es to fold into favourable conformations in order to promote membrane protein stability. The novel concept of detergent foldability introduced in the current study has potential in rational detergent design and membrane protein applications. [ABSTRACT FROM AUTHOR]

High‐grade serous ovarian cancer (HGS‐OvCa) is one of the most lethal gynaecological malignancies. Molecular classification identified an immunoreactive subtype of HGS‐OvCa; however, the immunologic characteristics of immunoreactive HGS‐OvcA remain unclear. In this study, 121 immunoreactive HGS‐OvCa samples were identified from a meta‐analysis of 5 large transcriptome profiling data sets using a cross‐platform immunoreactive HGS‐OvCa subgroup‐specific classifier. By comparing the gene expression profiles of immunoreactive HGS‐OvCa samples and normal tissues, 653 differentially expressed genes (DEGs) were identified. KEGG pathway analysis revealed that the leukocyte transendothelial migration pathways were significantly enriched in the immunoreactive HGS‐OvCa. Protein‐protein interaction analysis identified a module that showed strong involvement of the immune‐related chemokine signalling pathway. Moreover, the GSEA enrichment analysis showed a T‐cell subgroup and M1 macrophages were significantly enriched in immunoreactive OvCa compared with normal samples. Macrophage infiltration levels were significantly elevated in immunoreactive HGS‐OvCa compared with other OvCa subtypes. In addition, expression of immune checkpoint molecules VTCN1 and IDO1 was significantly increased in immunoreactive HGS‐OvCa. In summary, our results suggest that the immunoreactive HGS‐OvCa has unique molecular characteristics and a tumour‐associated immune microenvironment featured by increased infiltration of macrophages, rather than lymphocytes. VTCN1 could be potential targets for the treatment of immunoreactive HGS‐OvCa. [ABSTRACT FROM AUTHOR]

The structural and biochemical characterization of broadly neutralizing anti-HIV-1 antibodies (bNAbs) has been essential in guiding the design of potential vaccines to prevent infection by HIV-1. While these studies have revealed critical mechanisms by which bNAbs recognize and/or accommodate N-glycans on the trimeric envelope glycoprotein (Env), they have been limited to the visualization of high-mannose glycan forms only, since heterogeneity introduced from the presence of complex glycans makes it difficult to obtain high-resolution structures. 3.5 and 3.9 Å resolution crystal structures of the HIV-1 Env trimer with fully processed and native glycosylation were solved, revealing a glycan shield of high-mannose and complex-type N-glycans that were used to define the complete epitopes of two bNAbs. Here, the refinement of the N-glycans in the crystal structures is discussed and comparisons are made with glycan densities in glycosylated Env structures derived by single-particle cryo-electron microscopy. [ABSTRACT FROM AUTHOR]