{"title":"Temperature-Dependent Coarse-Grained Model for Simulations of Intrinsically Disordered Protein LCST and UCST Liquid-Liquid Phase Separations.","authors":"Yingmin Jiang,Tâp Ha-Duong","doi":"10.1021/acs.jctc.5c00212","DOIUrl":"https://doi.org/10.1021/acs.jctc.5c00212","url":null,"abstract":"Many intrinsically disordered proteins (IDPs) can undergo a liquid-liquid phase separation (LLPS) in water, depending on solution conditions (temperature, pH, and ionic strength). There are two types of LLPS that are controlled by temperature: those occurring above a lower critical solution temperature (LCST) and those occurring below an upper critical solution temperature (UCST). IDP coarse-grained (CG) models are particularly appropriate for investigating the physical and chemical factors that govern their LLPS and supramolecular organization. However, the development of CG models allowing simulations of both LCST and UCST behavior of temperature-sensitive IDPs is still in its infancy. In this context, we present here a novel temperature-dependent (TD) CG model for IDP simulations based on the MARTINI 3 force field. The model was developed by modifying the Lennard-Jones potentials between apolar or charged solute beads and water with a TD rescaling factor. It was parametrized to fit the TD potentials of mean force (PMF) between two apolar or two charged molecules computed using all-atom (AA) simulations. We show that the TD CG model is able to reproduce the experimentally known LLPS of both LCST and UCST low-complexity sequences and to estimate phase transition temperatures comparable to experimental measurements.","PeriodicalId":45,"journal":{"name":"Journal of Chemical Theory and Computation","volume":"64 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143876472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Stability of the Long-Range Corrected Exchange-Correlation Functional and the Proca Procedural Functional in Time-Dependent Density-Functional Theory.","authors":"Jared R Williams,Carsten A Ullrich","doi":"10.1021/acs.jctc.5c00122","DOIUrl":"https://doi.org/10.1021/acs.jctc.5c00122","url":null,"abstract":"Excitonic effects in the optical absorption spectra of solids can be described with time-dependent density-functional theory (TDDFT) in the linear-response regime, using a simple class of approximate, long-range corrected (LRC) exchange-correlation functionals. It was recently demonstrated that the LRC approximation can also be employed in real-time TDDFT to describe exciton dynamics. Here, we investigate the numerical stability of the time-dependent LRC approach using a two-dimensional model solid. It is found that the time-dependent Kohn-Sham equation with an LRC vector potential becomes more and more prone to instabilities for increasing exciton binding energies. The origin of these instabilities is traced back to time-averaged violations of the zero-force theorem, which leads to a simple and robust numerical stabilization scheme. This explains and justifies a recently proposed method by Dewhurst, J. K. [ Phys. Rev. B 2025, 111, L060302] to stabilize the LRC vector potential, known as the Proca procedural functional.","PeriodicalId":45,"journal":{"name":"Journal of Chemical Theory and Computation","volume":"69 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143872102","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Revisiting Machine Learning Potentials for Silicate Glasses: The Missing Role of Dispersion Interactions.","authors":"Alfonso Pedone,Marco Bertani,Matilde Benassi","doi":"10.1021/acs.jctc.5c00218","DOIUrl":"https://doi.org/10.1021/acs.jctc.5c00218","url":null,"abstract":"Machine learning interatomic potentials (MLIPs) offer a promising alternative to traditional force fields and ab initio methods for simulating complex materials such as oxide glasses. In this work, we present the first evaluation of the pretrained MACE (Multi-ACE) model [D.P. Kovács et al., J. Chem. Phys. 159(2023), 044118] for silicate glasses, using sodium silicates as a test case. We compare its performance with a DeePMD-based MLIP specifically trained on sodium silicate compositions [M. Bertani et al., J. Chem. Theory Comput. 20(2024), 1358-1370] and assess their accuracy in reproducing structural and dynamical properties. Additionally, we investigate the role of dispersion interactions by incorporating the D3(BJ) correction in both models. Our results show that while MACE accurately reproduces neutron structure factors, pair distribution functions, and Si[Qn] speciation, it performs slightly worst for elastic properties calculations. However, it is suitable for the simulations of sodium silicate glasses. The inclusion of dispersion interactions significantly improves the reproduction of density and elastic properties for both MLIPs, highlighting their critical role in glass modeling. These findings provide insight into the transferability of general MLIPs to disordered systems and emphasize the need for dispersion-aware training data sets in developing accurate force fields for oxide glasses.","PeriodicalId":45,"journal":{"name":"Journal of Chemical Theory and Computation","volume":"35 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143872106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"ANI-1xBB: An ANI-Based Reactive Potential for Small Organic Molecules.","authors":"Shuhao Zhang,Roman Zubatyuk,Yinuo Yang,Adrian Roitberg,Olexandr Isayev","doi":"10.1021/acs.jctc.5c00347","DOIUrl":"https://doi.org/10.1021/acs.jctc.5c00347","url":null,"abstract":"Reactive potentials serve as essential tools for investigating chemical reactions with moderate computational costs. However, traditional reactive potentials often depend on fixed, semiempirical parameters, which limits their accuracy and transferability. Overcoming these limitations can significantly expand the applicability of reactive potentials, enabling the simulation of a broader range of reactions under diverse conditions and the prediction of reaction properties, such as barrier heights. This work introduces ANI-1xBB, a novel ANI-based reactive ML potential trained on off-equilibrium molecular conformers generated through an automated bond-breaking workflow. ANI-1xBB significantly enhances the prediction of reaction energetics, barrier heights, and bond dissociation energies, surpassing those of conventional ANI models. Our results show that ANI-1xBB improves transition state modeling and reaction pathway prediction while generalizing effectively to pericyclic reactions and radical-driven processes. Furthermore, the automated data generation strategy supports the efficient construction of large-scale, high-quality reactive data sets, reducing reliance on expensive QM calculations. This work highlights ANI-1xBB as a practical model for accelerating the development of reactive machine learning potentials, offering new opportunities for modeling reaction phenomena.","PeriodicalId":45,"journal":{"name":"Journal of Chemical Theory and Computation","volume":"7 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143872023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Modeling Enzyme Reaction and Mutation by Direct Machine Learning/Molecular Mechanics Simulations.","authors":"Xinhu Sha,Zhuo Chen,Daiqian Xie,Yanzi Zhou","doi":"10.1021/acs.jctc.5c00149","DOIUrl":"https://doi.org/10.1021/acs.jctc.5c00149","url":null,"abstract":"Accurately modeling enzyme reactions through direct machine learning/molecular mechanics simulations remains challenging in describing the electrostatic coupling between the QM and MM subsystems. In this work, we proposed a reweighting ME (mechanic embedding) REANN (recursively embedded atom neural network) method that trains the potential and point charges of the QM subsystem in vacuo. The charge equilibration approach has been encoded into REANN to ensure conservation of the total charge of the QM subsystem. Electrostatic coupling is measured by point charges, and the polarization of the MM subsystem on the coupling can be corrected by thermodynamic perturbation after molecular dynamics simulations. We first constructed the REANN surfaces of potential energy and charges for the acylation of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) by aspirin. These surfaces allowed us to reproduce the free energy curves of B3LYP/MM-MD with a chemical accuracy. Subsequently, they were successfully applied to R513A of COX-2, reproducing the free energy barrier simulated by B3LYP/MM MD with a difference of less than 0.5 kcal mol-1 and a speedup of 80-fold, revealing our method can predict the activity of mutants accurately and rapidly. This method is expected to be applied in virtual screening in the future.","PeriodicalId":45,"journal":{"name":"Journal of Chemical Theory and Computation","volume":"136 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143876474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zeyu Zhang,Yangyang Zhang,Weitong Ren,Weiwei Zhang,Wenfei Li,Wei Wang
{"title":"Allosteric Regulation of Enzymatic Catalysis through Mechanical Force.","authors":"Zeyu Zhang,Yangyang Zhang,Weitong Ren,Weiwei Zhang,Wenfei Li,Wei Wang","doi":"10.1021/acs.jctc.5c00250","DOIUrl":"https://doi.org/10.1021/acs.jctc.5c00250","url":null,"abstract":"Mechanical force has been increasingly recognized to play crucial roles in regulating various cellular processes, which has inspired wide interest in elucidating the biophysical mechanism underlying these mechanobiological processes. In this work, we investigate the mechanical regulation of enzyme catalysis by developing a residue-resolved computational model capable of describing the full catalytic cycle of enzymes under mechanical force. Intriguingly, for a model enzyme, adenylate kinase, we showed that applying tensile forces with biologically relevant strength can increase the enzymatic activity. Further analysis showed that mechanical tensile force allosterically modifies the global free energy landscape and conformational dynamics of the protein, which then promotes the rate-limiting product release step of the enzymatic cycle. The effect of mechanical allostery on enzyme catalysis depends on the intrinsic conformational propensity of the enzymes. The crucial role of mechanical allostery in enzymatic catalysis elucidated in this work sheds important insights into the biophysical principle of enzymatic regulation and suggests a possible strategy for fine-tuning the functioning dynamics of biological enzymes.","PeriodicalId":45,"journal":{"name":"Journal of Chemical Theory and Computation","volume":"128 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Spatial and Sequential Topological Analysis of Molecular Dynamics Simulations of IgG1 Fc Domains.","authors":"Melinda Kleczynski,Christina Bergonzo,Anthony J Kearsley","doi":"10.1021/acs.jctc.5c00161","DOIUrl":"https://doi.org/10.1021/acs.jctc.5c00161","url":null,"abstract":"Monoclonal antibodies are utilized in a wide range of biomedical applications. The NIST monoclonal antibody is a resource for developing analysis methods for monoclonal antibody based biopharmaceutical platforms. Techniques from topological data analysis quantify structural features such as loops and tunnels which are not easily measured by classical data analysis methods. In this paper, we introduce the Gaussian CROCKER column differences (GCCD) matrix, which augments standard topological data analysis summaries with biological sequence information. We use GCCD matrices to successfully differentiate between glycosylated and aglycosylated conformations from molecular dynamics simulations of the NIST monoclonal antibody Fc domain. We are optimistic that other researchers will be able to utilize GCCD matrices to quantify multiscale spatial and sequential features.","PeriodicalId":45,"journal":{"name":"Journal of Chemical Theory and Computation","volume":"7 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Unitary Block-Correlated Coupled Cluster Ansatz Based on the Generalized Valence Bond Wave Function for Quantum Simulation.","authors":"Jiaqi Hu,Qingchun Wang,Shuhua Li","doi":"10.1021/acs.jctc.5c00239","DOIUrl":"https://doi.org/10.1021/acs.jctc.5c00239","url":null,"abstract":"Strongly correlated (SC) systems present significant challenges for classical quantum chemistry methods. Quantum computing, particularly the variational quantum eigensolver (VQE), offers a promising framework to address these challenges by inherently supporting exponentially large configuration spaces. However, its application to SC systems remains limited due to the single-reference nature of the widely used ansatzes such as unitary coupled cluster (UCC). To address this challenge, we propose the generalized valence bond-based unitary block correlated coupled cluster (GVB-UBCCC) method. This novel ansatz incorporates the multiconfigurational nature of generalized valence bond (GVB) and the accuracy of block correlated coupled cluster (BCCC) methods, making it well-suited for SC systems. We have implemented the GVB-UBCCC method with up to two-block correlation (GVB-UBCCC2) and applied it to investigate ground-state energies for several SC systems, including H4, the water dimer, N2H2, and S6, at most described by 24 qubits. Our approach demonstrates that for these systems, GVB-UBCCC2 can achieve more accurate ground-state energies than UCCSD in most cases while requiring only O(N2) quantum gates and parameters, as opposed to the O(N4) scaling of UCCSD. The results highlight the effectiveness and potential advantages of GVB-UBCCC in SC systems.","PeriodicalId":45,"journal":{"name":"Journal of Chemical Theory and Computation","volume":"21 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ensemble Adaptive Sampling Scheme: Identifying an Optimal Sampling Strategy via Policy Ranking.","authors":"Hassan Nadeem,Diwakar Shukla","doi":"10.1021/acs.jctc.4c01488","DOIUrl":"https://doi.org/10.1021/acs.jctc.4c01488","url":null,"abstract":"Efficient sampling in biomolecular simulations is critical for accurately capturing the complex dynamic behaviors of biological systems. Adaptive sampling techniques aim to improve efficiency by focusing computational resources on the most relevant regions of the phase space. In this work, we present a framework for identifying the optimal sampling policy through metric-driven ranking. Our approach systematically evaluates the policy ensemble and ranks the policies based on their ability to explore the conformational space effectively. Through a series of biomolecular simulation case studies, we demonstrate that the choice of a different adaptive sampling policy at each round significantly outperforms single policy sampling, leading to faster convergence and improved sampling performance. This approach takes an ensemble of adaptive sampling policies and identifies the optimal policy for the next round based on current data. Beyond presenting this ensemble view of adaptive sampling, we also propose two sampling algorithms that approximate this ranking framework on the fly. The modularity of this framework allows incorporation of any adaptive sampling policy, making it versatile and suitable as a comprehensive adaptive sampling scheme.","PeriodicalId":45,"journal":{"name":"Journal of Chemical Theory and Computation","volume":"5 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alexander A Sadamune,Robert R Lucchese,C William McCurdy,Frank L Yip
{"title":"Extraction of Double Photoionization Amplitudes from Full-Scattered Wave Functions.","authors":"Alexander A Sadamune,Robert R Lucchese,C William McCurdy,Frank L Yip","doi":"10.1021/acs.jctc.5c00197","DOIUrl":"https://doi.org/10.1021/acs.jctc.5c00197","url":null,"abstract":"Although cross sections for double photoionization (DPI) are much smaller than single photoionization cross sections, DPI by a single photon is a sensitive means of probing correlated electron dynamics. We extend a rigorous method for computing double ionization amplitudes in both time-independent and time-dependent computational formalisms by eliminating the requirement that the one-electron testing functions used to extract DPI amplitudes are continuum eigenfunctions that are orthogonal to the singly ionized states of the target. It is demonstrated that simple Coulomb testing functions can be used in an integral for the DPI amplitude restricted to the interaction region if few low-energy bound states of the singly charged ion are projected out of the full-scattered wave solution, resulting in surprisingly accurate triply and singly differential cross sections. These findings will simplify calculations of DPI amplitudes in more complicated polyatomic molecular targets than the benchmark two-electron systems considered here.","PeriodicalId":45,"journal":{"name":"Journal of Chemical Theory and Computation","volume":"52 1","pages":""},"PeriodicalIF":5.5,"publicationDate":"2025-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143857337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}