98%
921
2 minutes
20
Fluorescence-detected linear dichroism microscopy allows observing various molecular processes in living cells, as well as obtaining quantitative information on orientation of fluorescent molecules associated with cellular features. Such information can provide insights into protein structure, aid in development of genetically encoded probes, and allow determinations of lipid membrane properties. However, quantitating and interpreting linear dichroism in biological systems has been laborious and unreliable. Here we present a set of open source ImageJ-based software tools that allow fast and easy linear dichroism visualization and quantitation, as well as extraction of quantitative information on molecular orientations, even in living systems. The tools were tested on model synthetic lipid vesicles and applied to a variety of biological systems, including observations of conformational changes during G-protein signaling in living cells, using fluorescent proteins. Our results show that our tools and model systems are applicable to a wide range of molecules and polarization-resolved microscopy techniques, and represent a significant step towards making polarization microscopy a mainstream tool of biological imaging.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7881160 | PMC |
http://dx.doi.org/10.1038/s42003-021-01694-1 | DOI Listing |
J Synchrotron Radiat
November 2025
State Key Laboratory of Chemical Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, People's Republic of China.
This study develops an integrated X-ray absorption spectroscopy (XAS) photoemission electron microscopy (PEEM) platform on beamline BL09U at the Shanghai Synchrotron Radiation Facility (SSRF), enabling nanoscale characterization of complex materials through energy-resolved imaging and local-area XAS. By using the wide range of energy tunability, full access to different polarizations and PEEM's surface sensitivity, we have established a gap-monochromator control system under the EPICS framework to synchronize the elliptically polarized undulator (EPU) gap and monochromator energy dynamically, optimizing photon flux stability for absorption fine structure analysis. Combining X-ray magnetic circular dichroism (XMCD) and X-ray magnetic linear dichroism (XMLD) with PEEM and local-area XAS, this platform achieves concurrent mapping of electronic structures and magnetic domains in ferromagnetic nano-patterns, as demonstrated through our studies of NiFe Permalloy using this system.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2025
Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur 208016, India.
Agonist-induced interaction of G protein-coupled receptors (GPCRs) with β-arrestins (βarrs) is a critical mechanism that regulates the spatiotemporal pattern of receptor localization and signaling. While the underlying mechanism governing GPCR-βarr interaction is primarily conserved and involves receptor activation and phosphorylation, there are several examples of receptor-specific fine-tuning of βarr-mediated functional outcomes. Considering the key contribution of conformational plasticity of βarrs in driving receptor-specific functional responses, it is important to develop novel sensors capable of reporting distinct βarr conformations in cellular context.
View Article and Find Full Text PDFAnal Chem
August 2025
Department Guangzhou Key Laboratory of Analytical Chemistry for Biomedicine, GDMPA Key Laboratory for Process Control and Quality Evaluation of Chiral Pharmaceuticals, School of Chemistry, South China Normal University, Guangzhou 510006, Guangdong, China.
To address the challenges in detecting chloramphenicol (CAP) in complex food matrices, this study developed a magnetic solid-phase microextraction coupled with a high-performance liquid chromatography (MSPME-HPLC) system that integrates machine learning and molecular recognition. The system employs magnetic SiO@FeO nanoparticles as the carrier and combines the dual recognition functions of carboxylated pillar[5]arene (CP[5]A) and aptamer (Apt) to create a nanocomposite separation material, Apt-MIP-CP[5]A@SiO@FeO (AC-MSF). Bayesian optimization and six machine learning models (e.
View Article and Find Full Text PDFJ Am Chem Soc
August 2025
Department of Chemistry, Graduate School of Advanced Science and Engineering, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan.
To understand the vortex flow-directed circular dichroism (CD) effect observed in homogeneous solutions containing supramolecular structures, the macroscopic order formed by supramolecular structures oriented within a flow must be visualized. In this study, a bis(phenylisoxazolyl)benzene-attached platinum complex was found to self-assemble to form uniform anisotropic platelet nanostructures that are oriented within a flow, thereby generating a chiral macroscopic order that is responsible for CD and linear dichroism (LD) effects only in the vortex flow regime. Cooperative self-assembly of a bis(phenylisoxazolyl)benzene-attached platinum complex via controlled supramolecular polymerization produced anisotropic platelet nanostructures with a narrow polydispersity index.
View Article and Find Full Text PDFCoherent coupling between optical modes plays a vital role in manipulating the light field and its interaction with matter. Here, we investigate the chirality-induced strong coupling between leaky guided modes (GMs) with orthogonal polarizations in a chiral metasurface waveguide in the near-infrared frequencies, which consists of a square lattice of Ge dimers with broken symmetry and an underlying SiN waveguide layer deposited on a silica substrate. We find that mode coupling between two orthogonal GMs can be induced by introducing chirality to the metasurface waveguide when illuminated with circularly polarized light.
View Article and Find Full Text PDF