Dynamics Of Complexes Research Articles

Exploring the antisnake venom Potential of Zingiber officinale and its bioactive compounds against Naja nigricollis venom through computational approaches and experimental validation.

Snakebite envenomation remains a significant medical challenge, particularly in tropical and subtropical regions. The present study investigates the inhibitory potential of Zingiber officinale (ginger) and its bioactive compounds against Naja nigricollis venom using in silico approaches and animal models. No protection was observed in the in vivo studies but the extract of the plant was able to prolong the time of death with mean survival time ranging from 2.01 - 2.83 hours. In terms of the in vitro studies, the extract was able to significantly (p<0.05) detoxify the N. nigricollis venom by 80 % at the graded doses; standard antisnake venom (ASV) offered 100 % protection to mice. Molecular docking analysis revealed strong binding affinities between the bioactive compounds and the PLA2 enzyme, indicating potential inhibitory effects. The stability and dynamics of the protein-ligand complexes were further validated through molecular dynamics (MD) simulations, which confirmed the persistence of these interactions over time. In conclusion, the findings suggest that the bioactive compounds from Z. officinale could serve as promising inhibitors of PLA2, providing a foundation for the development of novel snakebite envenomation therapies.

New targets and biomarkers for doxorubicin-induced cardiotoxicity in humans: implications drawn from toxicogenomic data and molecular modelling

The doxorubicin-induced cardiotoxicity continues to be a life-threatening adverse effect in the clinic. Doxorubicin-induced acute cardiotoxicity is reversible, whereas chronic cardiotoxicity is irreversible, leading to dilated cardiomyopathy and heart failure. The aim of this study was to identify the molecular mechanisms associated with doxorubicin metabolites in doxorubicin-induced chronic cardiotoxicity. For this purpose, literature searches and in silico toxicogenomic analyses were conducted using various tools, including the Comparative Toxicogenomic Database, GeneMANIA, Metascape, MIENTURNET, ChEA3, and AutoDock. Additionally, molecular dynamics simulations were performed for 500 ns using Schrödinger software to assess the stability and dynamics of the representative docked complexes. We observed that doxorubicin biotransformed into five metabolites in the human heart and identified 11 common genes related to doxorubicin, its metabolites, dilated cardiomyopathy, and heart failure. Our findings revealed that doxorubicin and its metabolites primarily exhibited binding affinity to the beta-1 adrenergic receptor and fatty acid synthase. Furthermore, we identified several key transcription factors, especially the Homeobox protein Nkx-2.6, and hsa-miR-183-3p associated with this cardiotoxicity. Finally, we observed that, in addition to doxorubicinol, 7-deoxidoxorubicinone, another metabolite of doxorubicin, may also contribute to this cardiotoxicity. These findings contribute to our understanding of the processes underlying doxorubicin-induced chronic cardiotoxicity.

Molecular insights from structural dynamics of HER2-inhibitor complexes pave the way for new breast cancer drugs

The human epidermal growth factor receptor 2 (HER2) is closely associated with the development and progression of breast cancer, making it a critical target for therapeutic interventions. In this study, we employed a comprehensive computational drug discovery strategy to identify potential inhibitors of HER2. Our approach combined virtual screening, re-docking procedures, molecular dynamics (MD) simulations, and free energy landscape analysis using principal component analysis (PCA). From the extensive PubChem library, we initially screened 733 compounds for their binding potential to HER2, using docking scores as a primary filter. These scores ranged notably from −11.172 to −7.028 kcal/mol, indicating substantial binding capacities. Following this screening, we selected four promising compounds (PubChem CID 166029206, 166544027, 21031510, and 11712721) along with a control compound (70I) for in-depth analysis. Utilizing the Amber software suite for MD simulations, we conducted 200-nanosecond simulations to assess the interactions and binding efficiencies of these selected compounds with HER2. We analysed the molecular interactions through various parameters such as root mean square deviation (RMSD), root mean square fluctuation (RMSF), and hydrogen bond formation patterns, free binding energy calculations. The PCA-based free energy landscape analysis revealed that these compounds consistently occupied a distinct low-energy basin, indicating their high stability and strong binding affinity for the HER2. This detailed analysis provided insights into the stability and conformational dynamics of these potential inhibitors when bound to the HER2. Our findings pave the way for further experimental validation and development of these compounds as therapeutic agents in breast cancer treatment.

In-silico and in-vitro studies to identify potential inhibitors of SARS-CoV-2 spike protein from Omani medicinal plants

In the quest for novel therapeutic agents against SARS-CoV-2, the proposed study explores the potential of traditional Omani medicinal plants, focusing on the efficacy of natural ligands against the virus's Spike protein. Among 437 identified medicinal plants across Oman, 47 species that are documented for their traditional use in treating respiratory infections, with 30 species' ligands available were chosen for analysis. Molecular docking was performed using Autodock Vina on these ligands, yielding 406 unique ligands post-duplication removal. The binding affinities of target-ligand complexes were precisely determined, ranking them by interaction strength. This process identified Corilagin, a phytochemical from the Acalypha indica plant (locally known as Aeyan Al Aqrada), as the most promising inhibitor. Subsequent analyses using GROMACS for molecular dynamics simulation confirmed its binding stability and interaction dynamics of the Corilagin-protein complex. The in-vitro studies further validated Corilagin's inhibitory effect on SARS-CoV-2, demonstrating a remarkable 92 % inhibition at 0.5 mM concentration. Dilution studies to ascertain the IC50 value revealed Corilagin's high potency at a micromolar level (IC50 = 2.15 ± 0.13 μM), underscoring its potential as a drug candidate for SARS-CoV-2 treatment. These findings highlight the significance of ethnomedicine and in-silico methodologies in drug discovery, offering promising directions for future antiviral research.

The leucine-rich repeat receptor kinase QSK1 regulates PRR-RBOHD complexes targeted by the bacterial effector HopF2Pto.

Plants detect pathogens using cell-surface pattern recognition receptors (PRRs) such as ELONGATION Factor-TU (EF-TU) RECEPTOR (EFR) and FLAGELLIN SENSING 2 (FLS2), which recognize bacterial EF-Tu and flagellin, respectively. These PRRs belong to the leucine-rich repeat receptor kinase (LRR-RK) family and activate the production of reactive oxygen species via the NADPH oxidase RESPIRATORY BURST OXIDASE HOMOLOG D (RBOHD). The PRR-RBOHD complex is tightly regulated to prevent unwarranted or exaggerated immune responses. However, certain pathogen effectors can subvert these regulatory mechanisms, thereby suppressing plant immunity. To elucidate the intricate dynamics of the PRR-RBOHD complex, we conducted a comparative coimmunoprecipitation analysis using EFR, FLS2, and RBOHD in Arabidopsis thaliana. We identified QIAN SHOU KINASE 1 (QSK1), an LRR-RK, as a PRR-RBOHD complex-associated protein. QSK1 downregulated FLS2 and EFR abundance, functioning as a negative regulator of PRR-triggered immunity (PTI). QSK1 was targeted by the bacterial effector HopF2Pto, a mono-ADP ribosyltransferase, reducing FLS2 and EFR levels through both transcriptional and transcription-independent pathways, thereby inhibiting PTI. Furthermore, HopF2Pto transcriptionally downregulated PROSCOOP genes encoding important stress-regulated phytocytokines and their receptor MALE DISCOVERER 1-INTERACTING RECEPTOR-LIKE KINASE 2. Importantly, HopF2Pto requires QSK1 for its accumulation and virulence functions within plants. In summary, our results provide insights into the mechanism by which HopF2Pto employs QSK1 to desensitize plants to pathogen attack.

Metastasis-Associated Lung Adenocarcinoma Transcript 1 (MALAT1) lncRNA Conformational Dynamics in Complex with RNA-Binding Protein with Serine-Rich Domain 1 (RNPS1) in the Pan-cancer Splicing and Gene Expression.

Alternative splicing events increase the transcriptomic and proteomic complexity in cancers. Overexpression of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a highly conserved lncRNA, is widely known to promote cancer development, one mechanism for which may be through the regulation of alternative splicing and, thereby, gene expression. Its regulatory interactions with proteins have been a subject of much interest, yet little research has been carried out on the mechanisms adopted. It has been observed that MALAT1 binds to RNA-binding protein with serine-rich domain 1 (RNPS1), being colocalized in the nuclear speckles, and together, these two binding partners may regulate alternative splicing. Upregulated RNPS1 is predicted to play a key role in the pan-cancer development. Experimental tertiary structure of full-length MALAT1 is currently lacking despite the availability of the 3D structure of 3' expression and nuclear retention element. We hypothesize that the computationally modeled tertiary structures of the specific binding motifs in the M-region, E-region, and full-length structures of MALAT1 may adopt a modular structure and bind to the RNPS1 loop region of RS/P domain involved in exon skipping, interacting in a manner fully consistent with the biochemical experiments. Extensive observations using the powerful molecular dynamics (MD) simulations of MALAT1 regions bound to RNPS1 suggested that all three regions form interactive, yet stable complexes. The ranking of the MM-GBSA- and MM-PBSA-derived binding free energies between these complexes corroborated well in the MD simulations and experiments. Energy decomposition analyses suggested that arginines in the RNPS1 protein are among the major contributors toward the binding free energies as calculated by MM-GBSA present in the Amber package; while among the nucleotides, the major contributors were nucleotides with G and A nucleobases, with more contributory effect in comparison to arginines, across the bound M-region, E-region, and full-length MALAT1. This suggests that specific purines play a greater role in the complex formation, in a loop-specific manner, and the more proactive approach in complexation tilts toward MALAT1. To the best of our knowledge, our studies are the first studies taking a unique approach, utilizing the binding motifs to deduce a tertiary structure of MALAT1, toward our understanding of the lncRNA-protein interactions, stability, and binding on a structural basis. The therapeutic implications of targeting this complex formation to regulate splicing and hence, oncogenesis, is further envisaged.

Visualization of Type IV-A1 CRISPR-mediated repression of gene expression and plasmid replication.

Type IV CRISPR-Cas (clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins) effector complexes are often encoded on plasmids and are proposed to prevent the replication of competing plasmids. The Type IV-A1 CRISPR-Cas system of Pseudomonas oleovorans additionally harbors a CRISPR RNA (crRNA) that tightly regulates the transcript levels of a chromosomal target and represents a natural CRISPR interference (CRISPRi) tool. This study investigates CRISPRi effects of this system using synthetic crRNAs against genome and plasmid sequences. Targeting of reporter genes revealed extended interference in P. oleovorans and Escherichia coli cells producing recombinant CRISPR ribonucleoprotein (crRNP) complexes. RNA sequencing (RNA-seq) analyses of Type IV-A1 CRISPRi-induced transcriptome alterations demonstrated highly effective long-range downregulation of histidine operon expression, whereas CRISPRi effects of dCas9 remained limited to the vicinity of its binding site. Single-molecule microscopy uncovered the localization dynamics of crRNP complexes. The tracks of fluorescently labeled crRNPs co-localized with regions of increased plasmid replication, supporting efficient plasmid targeting. These results identify mechanistic principles that facilitate the application of Type IV-A1 CRISPRi for the regulation of gene expression and plasmid replication.

Integrating computational methods and in vitro experimental validation reveals the pharmacological mechanism of Selaginella bryopteris (L.) Baker targeting major proteins in breast cancer

Breast cancer remains a significant global health challenge, necessitating the exploration of novel therapeutic options. The present study employs an integrated approach encompassing network pharmacology, molecular docking, molecular dynamics simulations, and in-vitro validation to investigate the potential of Selaginella bryopteris in breast cancer treatment. Initial network pharmacology analysis revealed different potential targets and pathways associated with breast cancer that could be modulated by S. bryopteris phytochemical constituents. Molecular docking and dynamics simulations further elucidated the stability and dynamics of protein-ligand complexes (lanaroflavone–EGFR and sequoiaflavone-CTNNB1). The in-vitro assays demonstrated the ability of S. bryopteris crude extract to inhibit cancer cell growth (IC50 - 78.34 μg/mL) migration and invasion, supporting the computational predictions. The integrated approach employed in the present study offers a robust framework for the systematic exploration of S. bryopteris in drug discovery as a promising candidate for breast cancer treatment.

Molecular architecture and functional dynamics of the pre-incision complex in nucleotide excision repair

Nucleotide excision repair (NER) is vital for genome integrity. Yet, our understanding of the complex NER protein machinery remains incomplete. Combining cryo-EM and XL-MS data with AlphaFold2 predictions, we build an integrative model of the NER pre-incision complex(PInC). Here TFIIH serves as a molecular ruler, defining the DNA bubble size and precisely positioning the XPG and XPF nucleases for incision. Using simulations and graph theoretical analyses, we unveil PInC’s assembly, global motions, and partitioning into dynamic communities. Remarkably, XPG caps XPD’s DNA-binding groove and bridges both junctions of the DNA bubble, suggesting a novel coordination mechanism of PInC’s dual incision. XPA rigging interlaces XPF/ERCC1 with RPA, XPD, XPB, and 5′ ssDNA, exposing XPA’s crucial role in licensing the XPF/ERCC1 incision. Mapping disease mutations onto our models reveals clustering into distinct mechanistic classes, elucidating xeroderma pigmentosum and Cockayne syndrome disease etiology.

Photoinduced Nonadiabatic Dynamics of a Single-Walled Carbon Nanotube-Porphyrin Complex.

Single-walled carbon nanotubes (SWCNTs) have gained a lot of attention in the past few decades due to their promising optoelectronic properties. In addition, SWCNTs can form complexes that have good chemical stability and transport properties with other optical functional materials through noncovalent interactions. Elucidating the detailed mechanism of these complexes is of great significance for improving their optoelectronic properties. Nevertheless, simulating the photoinduced dynamics of these complexes accurately is rather challenging since they usually contain hundreds of atoms. To save computational efforts, most of the previous works have ignored the excitonic effects by employing nonadiabatic carrier (electron and hole) dynamics simulations. To properly consider the influence of excitonic effects on the photoinduced ultrafast processes of the SWCNT-tetraphenyl porphyrin (H2TPP) complex and to further improve the computational efficiency, we developed the nonadiabatic molecular dynamics (NAMD) method based on the extended tight binding-based simplified Tamm-Dancoff approximation (sTDA-xTB), which is applied to study the ultrafast photoinduced dynamics of the noncovalent SWCNT-porphyrin complex. In combination with statically electronic structure calculations, the present work successfully reveals the detailed microscopic mechanism of the ultrafast excitation energy transfer process of the complex. Upon local excitation on the H2TPP molecule, an ultrafast energy transfer process occurs from H2TPP (SWCNT-H2TPP*) to SWCNT (SWCNT*-H2TPP) within 10 fs. Then, two slower processes corresponding to the energy transfer from H2TPP to SWCNT and hole transfer from H2TPP to SWCNT take place in the 1 ps time scale. The sTDA-xTB-based electronic structure calculation and NAMD simulation results not only match the previous experimental observations from static and transient spectra but also provide more insights into the detailed information on the complex's photoinduced dynamics. Therefore, the sTDA-xTB-based NAMD method is a powerful theoretical tool for studying the ultrafast photoinduced dynamics in large extended systems with a large number of electronically excited states, which could be helpful for the subsequent design of SWCNT-based functional materials.

Mpsqd: A matrix product state based Python package to simulate closed and open system quantum dynamics.

We introduce a Python package based on matrix product states (MPS) to simulate both the time-dependent Schrödinger equation (TDSE) and the hierarchical equations of motion (HEOM). The wave function in the TDSE or the reduced density operator/auxiliary density operators in the HEOM are represented using MPS. A matrix product operator (MPO) is then constructed to represent the Hamiltonian in the TDSE or the generalized Liouvillian in the HEOM. The fourth-order Runge-Kutta method and the time-dependent variational principle are used to propagate the MPS. Several examples, including the nonadiabatic interconversion dynamics of the pyrazine molecule, excitation energy transfer dynamics in molecular aggregates and photosynthetic light-harvesting complexes, the spin-boson model, a laser driven two-state model, the Holstein model, and charge transport in the Anderson impurity model, are presented to demonstrate the capability of the package.

The adverse effect of ciprofloxacin treatment can be related to the increased thermal stability of monomeric actin

AbstractActin is a major component of all sarcomere and cytoskeletal systems and thus plays a crucial role in muscle and cellular movement. The molecular dynamics of actomyosin complexes are obtaining the central machinery of force generation during contraction. Nalidixic acid, discovered in 1962—the primary compound of the quinolone, fluoroquinolone-type antibiotics—in the forms of its improved derivatives are still widely used today. One of the most commonly used drugs in this class is ciprofloxacin (CF). It was observed that after the use of these drugs—during longer or shorter administration or even after their use—several side effects such as muscle pain (myalgia), muscle spasms, and muscle atrophy also occur, and muscle damage and rupture may be associated with muscle cell death (rhabdomyolysis). In medical cases, muscle weakness after CF treatment can be related to the CF-actin interaction. Here, we studied the effect of CF on skeletal muscle actin using differential scanning calorimetry (DSC). We obtained evident data that CF binding increases the structural stability of G actin and slightly weakens the F actin filaments. The stability change of actin in myofilaments can lead to the adverse effect of CF.

Ultrafast temporal-spectral analysis probes isomeric dynamics in a dissipative soliton resonator

Self-assembly of dissipative solitons arouses versatile configurations of molecular complexes, enriching intriguing dynamics in mode-locked lasers. The ongoing studies fuel the analogy between matter physics and optical solitons, and stimulate frontier developments of ultrafast optics. However, the behaviors of multiple constituents within soliton molecules still remain challenging to be precisely unveiled, regarding both the intramolecular and intermolecular motions. Here, we introduce the concept of “soliton isomer” to elucidate the molecular dynamics of multisoliton complexes. The time-lens and time-stretch techniques assisted temporal-spectral analysis reveals the diversity of assembly patterns, reminiscent of the “isomeric molecule”. Particularly, we study the fine energy exchange during the intramolecular motions, therefore gaining insights into the degrees of freedom of isomeric dynamics beyond temporal molecular patterns. All these findings further answer the question of how far the matter-soliton analogy reaches and pave an efficient route for assisting the artificial manipulation of multisoliton structures.

Nanoscale dynamics of the cadherin–catenin complex bound to vinculin revealed by neutron spin echo spectroscopy

We report a neutron spin echo (NSE) study of the nanoscale dynamics of the cell-cell adhesion cadherin-catenin complex bound to vinculin. Our measurements and theoretical physics analyses of the NSE data reveal that the dynamics of full-length α-catenin, β-catenin, and vinculin residing in the cadherin-catenin-vinculin complex become activated, involving nanoscale motions in this complex. The cadherin-catenin complex is the central component of the cell-cell adherens junction (AJ) and is fundamental to embryogenesis, tissue wound healing, neuronal plasticity, cancer metastasis, and cardiovascular health and disease. A highly dynamic cadherin-catenin-vinculin complex provides the molecular dynamics basis for the flexibility and elasticity that are necessary for the AJs to function as force transducers. Our theoretical physics analysis provides a way to elucidate these driving nanoscale motions within the complex without requiring large-scale numerical simulations, providing insights not accessible by other techniques. We propose a three-way "motorman" entropic spring model for the dynamic cadherin-catenin-vinculin complex, which allows the complex to function as a flexible and elastic force transducer.

Spatio-temporal breather dynamics in microcomb soliton crystals

Solitons, the distinct balance between nonlinearity and dispersion, provide a route toward ultrafast electromagnetic pulse shaping, high-harmonic generation, real-time image processing, and RF photonic communications. Here we uniquely explore and observe the spatio-temporal breather dynamics of optical soliton crystals in frequency microcombs, examining spatial breathers, chaos transitions, and dynamical deterministic switching – in nonlinear measurements and theory. To understand the breather solitons, we describe their dynamical routes and two example transitional maps of the ensemble spatial breathers, with and without chaos initiation. We elucidate the physical mechanisms of the breather dynamics in the soliton crystal microcombs, in the interaction plane limit cycles and in the domain-wall understanding with parity symmetry breaking from third-order dispersion. We present maps of the accessible nonlinear regions, the breather frequency dependences on third-order dispersion and avoided-mode crossing strengths, and the transition between the collective breather spatio-temporal states. Our range of measurements matches well with our first-principles theory and nonlinear modeling. To image these soliton ensembles and their breathers, we further constructed panoramic temporal imaging for simultaneous fast- and slow-axis two-dimensional mapping of the breathers. In the phase-differential sampling, we present two-dimensional evolution maps of soliton crystal breathers, including with defects, in both stable breathers and breathers with drift. Our fundamental studies contribute to the understanding of nonlinear dynamics in soliton crystal complexes, their spatio-temporal dependences, and their stability-existence zones.

Simulation of the non-adiabatic dynamics of an enone-Lewis acid complex in an explicit solvent.

Unlocking the full potential of Lewis acid catalysis for photochemical transformations requires a comprehensive understanding of the ultrafast dynamics of substrate-Lewis acid complexes. In a previous article [Peschel et al., Angew. Chem. Int. Ed., 2021, 60, 10155], time-resolved spectroscopy supported by static calculations revealed that the Lewis acid remains attached during the relaxation of the model complex cyclohexenone-BF3. In contrast to the experimental observation, surface-hopping dynamics in the gas phase predicted ultrafast heterolytic dissociation. We attributed the discrepancy to missing solvent interactions. Thus, in this work, we present an interface between the SHARC and FermiONs++ program packages, which enables us to investigate the ultrafast dynamics of cyclohexenone-BF3 in an explicit solvent environment. Our simulations demonstrate that the solvent prevents the dissociation of the complex, leading to an intriguing dissociation-reassociation mechanism. Comparing the dynamics with and without triplet states highlights their role in the relaxation process and shows that the Lewis acid inhibits intersystem crossing. These findings provide a clear picture of the relaxation process, which may aid in designing future Lewis acid catalysts for photochemical applications. They underscore that an explicit solvent model is required to describe relaxation processes in weakly bound states, as energy transfer to the solvent is crucial for the system to reach its minimum geometries.

Rate-Engineered Plasmon-Enhanced Fluorescence for Real-Time Microsecond Dynamics of Single Biomolecules.

Single-molecule fluorescence has revealed a wealth of biochemical processes but does not give access to submillisecond dynamics involved in transient interactions and molecular dynamics. Here we overcome this bottleneck and demonstrate record-high photon count rates of >107 photons/s from single plasmon-enhanced fluorophores. This is achieved by combining two conceptual novelties: first, we balance the excitation and decay rate enhancements by the antenna's volume, resulting in maximum fluorescence intensity. Second, we enhance the triplet decay rate using a multicomponent surface chemistry that minimizes microsecond blinking. We demonstrate applications to two exemplary molecular processes: we first reveal transient encounters and hybridization of DNA with a 1 μs temporal resolution. Second, we exploit the field gradient around the nanoparticle as a molecular ruler to reveal microsecond intramolecular dynamics of multivalent complexes. Our results pave the way toward real-time microsecond studies of biochemical processes using an implementation compatible with existing single-molecule fluorescence methods.

In silico Molecular Docking and Dynamic Study of MDM2-p53 Inhibitor Alkaloids Extracted from Withania somnifera Against Tumor Growth

In today’s world, human tumor growth has become a critical health issue. Many patients experience ineffective chemotherapeutic treatments, prompting the need for alternative methods. Our recent research has explored active alkaloid extracts from Withania somnifera as potential inhibitors of the MDM2-p53 interaction, a key factor in tumor growth. Using in silico molecular docking and dynamic approaches, we identified eight effective alkaloids with high docking score are WithanolideD (–10.0Kcal/mol), Withanolide (–10.0Kcal/mol), WithaferinA ( ̶ 9.9Kcal/mol), WithanolideB ( ̶ 9.5Kcal/mol), WithalongolideA ( –9.4Kcal/mol), WithanolideE ( ̶ 9.4Kcal/mol), WithanolideA ( ̶ 9.0Kcal/mol), Withanone ( ̶ 8.9Kcal/mol). Among them, WithaferinA, WithanolideA, WithanolideD, WithanolideE, and Withanone demonstrated the most stable hydrogen bonding, stable RMSD, and RMSF. Lipinski’s rule of five, which assesses drug-like qualities, confirmed their potential through canonical SMILES verification. Molecular dynamics of the protein-ligand complex revealed that these docked complexes remain thermally stable, with consistent bond energy, dihedral angles, and stereochemical conformation over a 100 ns time frame. Our findings suggest that these alkaloids from Withania somnifera hold promise as effective treatments against tumor growth. Further investigation and exploration are necessary to confirm their efficacy in clinical settings.

The Unusual Functional Role of Protein Flexibility in Photosynthetic Light Harvesting: Protein Dynamics Studied Using Neutron Scattering

In addition to investigations of the three-dimensional protein structure, information on the dynamical properties of proteins is indispensable for an understanding of protein function in general. Correlations between protein dynamics and function are typically anticipated when both molecular mobility and function are concurrently affected under specific temperatures or hydration conditions. In contrast, excitation energy transfer within the major photosynthetic light-harvesting complex II (LHC II) presents an atypical case, as it remains fully operational even at cryogenic temperatures, primarily depending on the interactions between electronic states and involving harmonic protein vibrations only. This review summarizes recent work on vibrational and conformational protein dynamics of LHC II and directly relates these findings to its light-harvesting function. In addition, we give a comprehensive introduction into the use of neutron spectroscopy and molecular dynamics simulations to investigate the protein dynamics of photosynthetic protein complexes in solution, which is information complementary to that obtained by protein crystallography.

ALS-FUS mutations cause abnormal PARylation and histone H1.2 interaction, leading to pathological changes

The majority of severe early-onset and juvenile cases of amyotrophic lateral sclerosis (ALS) are caused by mutations in the FUS gene, resulting in rapid disease progression. Mutant FUS accumulates within stress granules (SGs), thereby affecting the dynamics of these ribonucleoprotein complexes. Here, we define the interactome of the severe mutant FUSP525L variant in human induced pluripotent stem cell (iPSC)-derived motor neurons. We find increased interaction of FUSP525L with the PARP1 enzyme, promoting poly-ADP-ribosylation (PARylation) and binding of FUS to histone H1.2. Inhibiting PARylation or reducing H1.2 levels alleviates mutant FUS aggregation, SG alterations, and apoptosis in human motor neurons. Conversely, elevated H1.2 levels exacerbate FUS-ALS phenotypes, driven by the internally disordered terminal domains of H1.2. In C.elegans models, knockdown of H1.2 and PARP1 orthologs also decreases FUSP525L aggregation and neurodegeneration, whereas H1.2 overexpression worsens ALS-related changes. Our findings indicate a link between PARylation, H1.2, and FUS with potential therapeutic implications.