Mechanistic Insights into Loop Dynamics in Reshaping the Conformation of YB-1 Cold Shock Domain.

The human Y-box binding protein 1 (YB-1) plays a crucial role in various cellular processes. The cold shock domain (CSD) of YB-1 is responsible for specific nucleic acid recognition and exhibits a unique β-barrel structure. While the CSD alone is unstable, the addition of 11 residues at the C-terminus significantly stabilizes the structure.

NMR Based Methods for Metabolites Analysis.

Metabolite analysis is essential for understanding the biochemical processes and pathways that sustain life, providing insights into the complex interactions within cellular systems and clinical examinations. This review explores recent applications of nuclear magnetic resonance (NMR) spectroscopy in metabolite studies. Various methods enhancing analytical accuracy for metabolome profiling and metabolic pathway studies, including spectral simplification techniques, quantitative NMR, high-resolution MAS NMR, and isotopic labeling, are discussed.

Structural insights into a highly flexible zinc finger module unravel INSM1 function in transcription regulation.

Orderly development of neuroendocrine and nervous system of mammals requires INSM1, a key regulator for cell differentiation. Ectopic expression of INSM1 is closely correlated with human neuroendocrine tumorigenesis, which makes INSM1 a reliable diagnostic biomarker and potential therapeutic target. To date, INSM1 is known as a transcription repressor binding to GGGG-contained DNA element and TEAD1 using its five zinc fingers (ZFs), while the binding mechanism remains unknown.

MRI Motion Correction Through Disentangled CycleGAN Based on Multi-Mask K-Space Subsampling.

This work proposes a new retrospective motion correction method, termed DCGAN-MS, which employs disentangled CycleGAN based onmulti-mask k-space subsampling (DCGAN-MS) to address the image domain translation challenge. The multi-mask k-space subsampling operator is utilized to decrease the complexity of motion artifacts by randomly discarding motion-affected k-space lines. The network then disentangles the subsampled, motion-corrupted images into content and artifact features using specialized encoders, and generates motion-corrected images by decoding the content features.

Aromatic-aromatic interactions drive fold switch of GA95 and GB95 with three residue difference.

Proteins typically adopt a single fold to carry out their function, but metamorphic proteins, with multiple folding states, defy this norm. Deciphering the mechanism of conformational interconversion of metamorphic proteins is challenging. Herein, we employed nuclear magnetic resonance (NMR), circular dichroism (CD), and all-atom molecular dynamics (MD) simulations to elucidate the mechanism of fold switching in proteins GA95 and GB95, which share 95% sequence homology.

Visualizing Dynamic Weak Interaction Networks of Fluorine Atoms within Proteins via NMR.

The utilization of fluorine probes in protein research has advanced our understanding of the nature of macromolecules. The diverse activities of proteins are governed by intricate weak interaction networks, yet the experimental detection presents a challenge. Herein, we have developed an NMR analytical method based on quantum coherent operations to characterize the weak chemical bonds of fluorine atoms within proteins that are bound to metal fluorides or labeled with fluorinated amino acids.

Deep learning enabled ultra-high quality NMR chemical shift resolved spectra.

High quality chemical shift resolved spectra have long been pursued in nuclear magnetic resonance (NMR). In order to obtain chemical shift information with high resolution and sensitivity, a neural network named spin echo to obtain chemical shifts network (SE2CSNet) is developed to process the NMR data acquired by the spin echo pulse sequence. Through detecting the change of phase in the spin echo spectra, SE2CSNet can accurately detect the chemical shift position of spectral signals.

Protein Condensates Unfold G-Quadruplex Resembling a Helicase Activity.

Membrane-less organelles, formed by liquid-liquid phase separation, participate in many vital cellular processes and have received extensive attention recently. A notable form of noncanonical nucleic acid secondary structure, G-quadruplex (G4), interacts with the scaffolding proteins in these membrane-less organelles and becomes an integral part of this condensed phase. However, the structure and stability features of the integrated G4 remain poorly characterized.

ATP promotes protein coacervation through conformational compaction.

Adenosine triphosphate (ATP) has been recognized as a hydrotrope in the phase separation process of intrinsically disordered proteins (IDPs). Surprisingly, when using the disordered Arg-Gly/Arg-Gly-Gly (RG/RGG) rich motif from the HNRNPG protein as a model system, we discover a biphasic relationship between the ATP concentration and IDP phase separation. We show that, at a relatively low ATP concentration, ATP dynamically interacts with the IDP, which neutralizes protein surface charges, promotes intermolecular interactions, and consequently promotes phase separation.

Rapid Targeted Screening and Identification of Active Ingredients in Herbal Extracts through Ligand-Detected NMR and Database Matching.

Herbal extracts are rich sources of active compounds that can be used for drug screening due to their diverse and unique chemical structures. However, traditional methods for screening these compounds are notably laborious and time-consuming. In this manuscript, we introduce a new high-throughput approach that combines nuclear magnetic resonance (NMR) spectroscopy with a tailored database and algorithm to rapidly identify bioactive components in herbal extracts.

Detecting biomarkers by dynamic nuclear polarization enhanced magnetic resonance.

Hyperpolarization stands out as a technique capable of significantly enhancing the sensitivity of nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI). Dynamic nuclear polarization (DNP), among various hyperpolarization methods, has gained prominence for its efficacy in real-time monitoring of metabolism and physiology. By administering a hyperpolarized substrate through dissolution DNP (dDNP), the biodistribution and metabolic changes of the DNP agent can be visualized spatiotemporally.

Using neural networks to obtain NMR spectra of both small and macromolecules from blood samples in a single experiment.

Metabolomics plays a crucial role in understanding metabolic processes within biological systems. Using specific pulse sequences, NMR-based metabolomics detects small and macromolecular metabolites that are altered in blood samples. Here we proposed a method called spectral editing neural network, which can effectively edit and separate the spectral signals of small and macromolecules in H NMR spectra of serum and plasma based on the linewidth of the peaks.

Microbial Tryptophan Metabolites Ameliorate Ovariectomy-Induced Bone Loss by Repairing Intestinal AhR-Mediated Gut-Bone Signaling Pathway.

Microbial tryptophan (Trp) metabolites acting as aryl hydrocarbon receptor (AhR) ligands are shown to effectively improve metabolic diseases via regulating microbial community. However, the underlying mechanisms by which Trp metabolites ameliorate bone loss via gut-bone crosstalk are largely unknown. In this study, supplementation with Trp metabolites, indole acetic acid (IAA), and indole-3-propionic acid (IPA), markedly ameliorate bone loss by repairing intestinal barrier integrity in ovariectomy (OVX)-induced postmenopausal osteoporosis mice in an AhR-dependent manner.

Trimethylamine N-oxide (TMAO) doubly locks the hydrophobic core and surfaces of protein against desiccation stress.

Interactions between proteins and osmolytes are ubiquitous within cells, assisting in response to environmental stresses. However, our understanding of protein-osmolyte interactions underlying desiccation tolerance is limited. Here, we employ solid-state NMR (ssNMR) to derive information about protein conformation and site-specific interactions between the model protein, SH3, and the osmolyte trimethylamine N-oxide (TMAO).

Targeting New Functions and Applications of Bacterial Two-Component Systems.

Two-component signal transduction systems (TCSs) are regulatory systems widely distributed in eubacteria, archaea, and a few eukaryotic organisms, but not in mammalian cells. A typical TCS consists of a histidine kinase and a response regulator protein. Functional and mechanistic studies on different TCSs have greatly advanced the understanding of cellular phosphotransfer signal transduction mechanisms.

Fast collective motions of backbone in transmembrane α helices are critical to water transfer of aquaporin.

Fast collective motions are widely present in biomolecules, but their functional relevance remains unclear. Herein, we reveal that fast collective motions of backbone are critical to the water transfer of aquaporin Z (AqpZ) by using solid-state nuclear magnetic resonance (ssNMR) spectroscopy and molecular dynamics (MD) simulations. A total of 212 residue site-specific dipolar order parameters and 158 N spin relaxation rates of the backbone are measured by combining the C- and H-detected multidimensional ssNMR spectra.

Studying protein stability in crowded environments by NMR.

Most proteins perform their functions in crowded and complex cellular environments where weak interactions are ubiquitous between biomolecules. These complex environments can modulate the protein folding energy landscape and hence affect protein stability. NMR is a nondestructive and effective method to quantify the kinetics and equilibrium thermodynamic stability of proteins at an atomic level within crowded environments and living cells.

Prediction of order parameters based on protein NMR structure ensemble and machine learning.

The fast motions of proteins at the picosecond to nanosecond timescale, known as fast dynamics, are closely related to protein conformational entropy and rearrangement, which in turn affect catalysis, ligand binding and protein allosteric effects. The most used NMR approach to study fast protein dynamics is the model free method, which uses order parameter S to describe the amplitude of the internal motion of local group. However, to obtain order parameter through NMR experiments is quite complex and lengthy.

Progress, Challenges and Opportunities of NMR and XL-MS for Cellular Structural Biology.

The validity of protein structures and interactions, whether determined under ideal laboratory conditions or predicted by AI tools such as Alphafold2, to precisely reflect those found in living cells remains to be examined. Moreover, understanding the changes in protein structures and interactions in response to stimuli within living cells, under both normal and disease conditions, is key to grasping proteins' functionality and cellular processes. Nevertheless, achieving high-resolution identification of these protein structures and interactions within living cells presents a technical challenge.

Combined NMR and MS-based metabonomics and real-time PCR analyses reveal dynamic metabolic changes of Ganoderma lucidum during fruiting body growing.

Ganoderma lucidum (G. lucidum) is a rare medicinal fungus with various beneficial properties. One of its main components, ganoderic acids (GAs), are important triterpenoids known for their sedative and analgesic, hepatoprotective, and anti-tumor activities.

F Nuclear Magnetic Resonance Fingerprinting Technique for Identifying and Quantifying G-Quadruplex Topology in Human Telomeric Overhangs.

G-quadruplexes (G4s) are noncanonical nucleic acid secondary structures with diverse topological features and biological roles. Human telomeric (Htelo) overhangs consisting of TTAGGG repeats can fold into G4s that adopt different topologies under physiological conditions. These G4s are potential targets for anticancer drugs.