Institute for Chemical Research (IIQ), Scientific Research Center "Isla de la Cartuja" (cicCartuja), University of Seville - CSIC, Seville, Spain.
Published: August 2024
AI Article Synopsis
Article Abstract
Compartmentalization of proteins by liquid-liquid phase separation (LLPS) is used by cells to control biochemical reactions spatially and temporally. Among them, the recruitment of proteins to DNA foci and nucleolar trafficking occur by biomolecular condensation. Within this frame, the oncoprotein SET/TAF-Iβ plays a key role in both chromatin remodeling and DNA damage response, as does nucleophosmin (NPM1) which indeed participates in nucleolar ribosome synthesis. Whereas phase separation by NPM1 is widely characterized, little is known about that undergone by SET/TAF-Iβ. Here, we show that SET/TAF-Iβ experiences phase separation together with respiratory cytochrome (C), which translocates to the nucleus upon DNA damage. Here we report the molecular mechanisms governing C-induced phase separation of SET/TAF-Iβ and NPM1, where two lysine-rich clusters of C are essential to recognize molecular surfaces on both partners in a specific and coordinated manner. C thus emerges as a small, globular protein with sequence-encoded heterotypic phase-separation properties.
Gut immunity is essential for maintaining intestinal health. Recent studies have identified that intracellular liquid-liquid phase separation (LLPS) may play a significant role in regulating gut immunity, however, the underlying mechanisms remain unclear. LLPS refers to droplet condensates formed through intracellular molecular interactions, which are crucial for the formation of membraneless organelles and biomolecules.
The pristine phases SS1(ZnO), SS2(MnO), and SS3 (CuO) photocatalysts and mixed phases of ZnO-based nanocomposites were synthesized by the sol-gel method. Whereas SS4 (g-CN) was prepared through polymerization of urea. The synthesized photocatalysts were characterized using TGA-DTA, XRD, DRS, PL, DLS, FTIR, SEM, TEM, and HRTEM.
Alloy nanocatalysts exhibit enhanced activity, selectivity, and stability mainly due to their versatile phases and atomic structures. However, nanocatalysts' "real" functional structures may vary from their as-synthesized status due to the structural and chemical changes during the activation and reaction conditions. Herein, we studied the activated CuPd/CeO nanocatalysts under the CO oxidation reaction featuring an atomic-scale phase separation process, resulting in a notable "hysteresis" in catalyst performance.
Nucleocapsid protein (N) of SARS-CoV-2 is a multivalent protein, which is responsible for viral replication, assembly, packaging and modulates host immune response. In this study, we report conformational measurements of N protein at different pH by observing transition in secondary and tertiary structural contents by biophysical and computational approaches. Spectroscopic measurements revealed that N protein loses its secondary and tertiary structure at extreme acidic pH while maintaining its native conformation at mild acidic and alkaline pH.
Proton transfer reaction mass spectrometry (PTR-MS) is often employed to characterize gas-phase compounds in both indoor and outdoor environments. PTR-MS measurements are usually made without upstream chromatographic separation, so it can be challenging to differentiate between an ion of interest, its isomers, and fragmentation products from other species all detected at the same mass-to-charge ratio. These isomeric contributions and fragmentation interferences can confound the determination of accurate compound mixing ratios, the assignment of accurate chemical properties, and corresponding analyses of chemical fate.
