1
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Dongmo Foumthuim CJ, Giacometti A. Solvent quality and solvent polarity in polypeptides. Phys Chem Chem Phys 2023; 25:4839-4853. [PMID: 36692363 DOI: 10.1039/d2cp05214h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Using molecular dynamics and thermodynamic integration, we report on the solvation process of seven polypeptides (GLY, ALA, ILE, ASN, LYS, ARG, GLU) in water and in cyclohexane. The polypeptides are selected to cover the full hydrophobic scale while varying their chain length from tri- to undeca-homopeptides, providing indications on possible non-additivity effects as well as the role of the peptide backbone in the overall stability of the polypeptides. The use of different solvents and different polypeptides allows us to investigate the relation between solvent quality - the capacity of a given solvent to fold/unfold a given biopolymer often described on a scale ranging from "good" to "poor"; and solvent polarity - related to the specific interactions of any solvent with respect to a reference solvent. Undeca-glycine is found to be the only polypeptide to have a stable collapse in water (polar solvent), with the other hydrophobic polypeptides displaying repeated folding and unfolding events in water, with polar polypeptides presenting even more complex behavior. By contrast, all polypeptides are found to keep an extended conformation in cyclohexane, irrespective of their polarity. All considered polypeptides are also found to have favorable solvation free energy independent of the solvent polarity and their intrinsic hydrophobicity, clearly highlighting the prominent stabilizing role of the peptide backbone - with the solvation process largely enthalpically dominated in polar polypeptides and partially entropically driven for hydrophobic polypeptides. Our study thus reveals the complexity of the solvation process of polypeptides defying the common view "like dissolves like", with the solute polarity playing the most prominent role. The absence of mirror symmetry upon the inversion of polarities of both the solvent and the polypeptides is confirmed.
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Affiliation(s)
- Cedrix J Dongmo Foumthuim
- Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca' Foscari di Venezia, Campus Scientifico, Edificio Alfa, via Torino 155, 30172 Venezia Mestre, Italy.
| | - Achille Giacometti
- Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca' Foscari di Venezia, Campus Scientifico, Edificio Alfa, via Torino 155, 30172 Venezia Mestre, Italy. .,European Centre for Living Technology (ECLT) Ca Bottacin, Dorsoduro 3911, Calle Crosera 30123 Venice, Italy
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2
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Data Structures and Algorithms for k-th Nearest Neighbours Conformational Entropy Estimation. BIOPHYSICA 2022. [DOI: 10.3390/biophysica2040031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Entropy of multivariate distributions may be estimated based on the distances of nearest neighbours from each sample from a statistical ensemble. This technique has been applied on biomolecular systems for estimating both conformational and translational/rotational entropy. The degrees of freedom which mostly define conformational entropy are torsion angles with their periodicity. In this work, tree structures and algorithms to quickly generate lists of nearest neighbours for periodic and non-periodic data are reviewed and applied to biomolecular conformations as described by torsion angles. The effect of dimensionality, number of samples, and number of neighbours on the computational time is assessed. The main conclusion is that using proper data structures and algorithms can greatly reduce the complexity of nearest neighbours lists generation, which is the bottleneck step in nearest neighbours entropy estimation.
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3
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Waibl F, Kraml J, Hoerschinger VJ, Hofer F, Kamenik AS, Fernández-Quintero ML, Liedl KR. Grid inhomogeneous solvation theory for cross-solvation in rigid solvents. J Chem Phys 2022; 156:204101. [PMID: 35649837 DOI: 10.1063/5.0087549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Grid Inhomogeneous Solvation Theory (GIST) has proven useful to calculate localized thermodynamic properties of water around a solute. Numerous studies have leveraged this information to enhance structure-based binding predictions. We have recently extended GIST toward chloroform as a solvent to allow the prediction of passive membrane permeability. Here, we further generalize the GIST algorithm toward all solvents that can be modeled as rigid molecules. This restriction is inherent to the method and is already present in the inhomogeneous solvation theory. Here, we show that our approach can be applied to various solvent molecules by comparing the results of GIST simulations with thermodynamic integration (TI) calculations and experimental results. Additionally, we analyze and compare a matrix consisting of 100 entries of ten different solvent molecules solvated within each other. We find that the GIST results are highly correlated with TI calculations as well as experiments. For some solvents, we find Pearson correlations of up to 0.99 to the true entropy, while others are affected by the first-order approximation more strongly. The enthalpy-entropy splitting provided by GIST allows us to extend a recently published approach, which estimates higher order entropies by a linear scaling of the first-order entropy, to solvents other than water. Furthermore, we investigate the convergence of GIST in different solvents. We conclude that our extension to GIST reliably calculates localized thermodynamic properties for different solvents and thereby significantly extends the applicability of this widely used method.
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Affiliation(s)
- Franz Waibl
- Center for Molecular Biosciences Innsbruck, Department of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, Innsbruck, Austria
| | - Johannes Kraml
- Center for Molecular Biosciences Innsbruck, Department of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, Innsbruck, Austria
| | - Valentin J Hoerschinger
- Center for Molecular Biosciences Innsbruck, Department of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, Innsbruck, Austria
| | - Florian Hofer
- Center for Molecular Biosciences Innsbruck, Department of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, Innsbruck, Austria
| | - Anna S Kamenik
- Center for Molecular Biosciences Innsbruck, Department of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, Innsbruck, Austria
| | - Monica L Fernández-Quintero
- Center for Molecular Biosciences Innsbruck, Department of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, Innsbruck, Austria
| | - Klaus R Liedl
- Center for Molecular Biosciences Innsbruck, Department of General, Inorganic and Theoretical Chemistry, University of Innsbruck, Innrain 80/82, Innsbruck, Austria
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4
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Cantarutti C, Vargas MC, Dongmo Foumthuim CJ, Dumoulin M, La Manna S, Marasco D, Santambrogio C, Grandori R, Scoles G, Soler MA, Corazza A, Fortuna S. Insights on peptide topology in the computational design of protein ligands: the example of lysozyme binding peptides. Phys Chem Chem Phys 2021; 23:23158-23172. [PMID: 34617942 DOI: 10.1039/d1cp02536h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Herein, we compared the ability of linear and cyclic peptides generated in silico to target different protein sites: internal pockets and solvent-exposed sites. We selected human lysozyme (HuL) as a model target protein combined with the computational evolution of linear and cyclic peptides. The sequence evolution of these peptides was based on the PARCE algorithm. The generated peptides were screened based on their aqueous solubility and HuL binding affinity. The latter was evaluated by means of scoring functions and atomistic molecular dynamics (MD) trajectories in water, which allowed prediction of the structural features of the protein-peptide complexes. The computational results demonstrated that cyclic peptides constitute the optimal choice for solvent exposed sites, while both linear and cyclic peptides are capable of targeting the HuL pocket effectively. The most promising binders found in silico were investigated experimentally by surface plasmon resonance (SPR), nuclear magnetic resonance (NMR), and electrospray ionization mass spectrometry (ESI-MS) techniques. All tested peptides displayed dissociation constants in the micromolar range, as assessed by SPR; however, both NMR and ESI-MS suggested multiple binding modes, at least for the pocket binding peptides. A detailed NMR analysis confirmed that both linear and cyclic pocket peptides correctly target the binding site they were designed for.
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Affiliation(s)
- Cristina Cantarutti
- Department of Medicine, University of Udine, Piazzale M. Kolbe 4, 33100 - Udine, Italy.
| | - M Cristina Vargas
- Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav), Unidad Mérida, Apartado Postal 73 "Cordemex", 97310, Mérida, Mexico
| | - Cedrix J Dongmo Foumthuim
- Department of Medicine, University of Udine, Piazzale M. Kolbe 4, 33100 - Udine, Italy. .,Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, Campus Scientifico - Via Torino 155, 30172 Mestre, Italy
| | - Mireille Dumoulin
- Centre for Protein Engineering, InBios, Department of Life Sciences, University of Liege, Liege, Belgium
| | - Sara La Manna
- Department of Pharmacy - University of Naples "Federico II", 80134, Naples, Italy
| | - Daniela Marasco
- Department of Pharmacy - University of Naples "Federico II", 80134, Naples, Italy
| | - Carlo Santambrogio
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza, Milan, Italy
| | - Rita Grandori
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza, Milan, Italy
| | - Giacinto Scoles
- Department of Medicine, University of Udine, Piazzale M. Kolbe 4, 33100 - Udine, Italy.
| | - Miguel A Soler
- Department of Medicine, University of Udine, Piazzale M. Kolbe 4, 33100 - Udine, Italy. .,Italian Institute of Technology (IIT), Via Melen - 83, B Block, 16152 - Genova, Italy
| | - Alessandra Corazza
- Department of Medicine, University of Udine, Piazzale M. Kolbe 4, 33100 - Udine, Italy.
| | - Sara Fortuna
- Department of Medicine, University of Udine, Piazzale M. Kolbe 4, 33100 - Udine, Italy. .,Italian Institute of Technology (IIT), Via Melen - 83, B Block, 16152 - Genova, Italy.,Department of Chemical and Pharmaceutical Sciences, University of Trieste, Via L. Giorgieri 1, 34127 Trieste, Italy
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5
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Fogolari F, Esposito G, Tidor B. Entropy of Two-Molecule Correlated Translational-Rotational Motions Using the kth Nearest Neighbor Method. J Chem Theory Comput 2021; 17:3039-3051. [PMID: 33856225 DOI: 10.1021/acs.jctc.1c00016] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The entropy associated with rotations, translations, and their coupled motions provides an important contribution to the free energy of many physicochemical processes such as association and solvation. The kth nearest neighbor method, which offers a convenient way to estimate the entropy in high-dimensional spaces, has been previously applied for translational-rotational entropy estimation. Here, we explore the possibility of extending the kth nearest neighbor method to the computation of the entropy of correlated translation-rotations of two molecules, i.e., in the product space of two translation-rotations, both referred to the same independent reference system, which is relevant for all cases in which the correlated translational-rotational motion of more than two molecules is involved. Numerical tests show that, albeit the relatively high dimensionality (12) of the space, the kth nearest neighbor approach provides an accurate estimate for the entropy of two correlated translational-rotational motions, even when computed from a limited number of samples.
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Affiliation(s)
- Federico Fogolari
- Dipartimento di Scienze Matematiche, Informatiche e Fisiche (DMIF), University of Udine, Via delle Scienze 206, 33100 Udine, Italy.,Istituto Nazionale Biostrutture e Biosistemi, Viale medaglie d'Oro 305, 00136 Roma, Italy
| | - Gennaro Esposito
- Istituto Nazionale Biostrutture e Biosistemi, Viale medaglie d'Oro 305, 00136 Roma, Italy.,Science and Math Division, New York University at Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates
| | - Bruce Tidor
- Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
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6
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Hanson AJ. The quaternion-based spatial-coordinate and orientation-frame alignment problems. Acta Crystallogr A Found Adv 2020; 76:432-457. [PMID: 32608360 PMCID: PMC7330932 DOI: 10.1107/s2053273320002648] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 02/25/2020] [Indexed: 12/02/2022] Open
Abstract
The general problem of finding a global rotation that transforms a given set of spatial coordinates and/or orientation frames (the `test' data) into the best possible alignment with a corresponding set (the `reference' data) is reviewed. For 3D point data, this `orthogonal Procrustes problem' is often phrased in terms of minimizing a root-mean-square deviation (RMSD) corresponding to a Euclidean distance measure relating the two sets of matched coordinates. This article focuses on quaternion eigensystem methods that have been exploited to solve this problem for at least five decades in several different bodies of scientific literature, where they were discovered independently. While numerical methods for the eigenvalue solutions dominate much of this literature, it has long been realized that the quaternion-based RMSD optimization problem can also be solved using exact algebraic expressions based on the form of the quartic equation solution published by Cardano in 1545; focusing on these exact solutions exposes the structure of the entire eigensystem for the traditional 3D spatial-alignment problem. The structure of the less-studied orientation-data context is then explored, investigating how quaternion methods can be extended to solve the corresponding 3D quaternion orientation-frame alignment (QFA) problem, noting the interesting equivalence of this problem to the rotation-averaging problem, which also has been the subject of independent literature threads. The article concludes with a brief discussion of the combined 3D translation-orientation data alignment problem. Appendices are devoted to a tutorial on quaternion frames, a related quaternion technique for extracting quaternions from rotation matrices and a review of quaternion rotation-averaging methods relevant to the orientation-frame alignment problem. The supporting information covers novel extensions of quaternion methods to the 4D Euclidean spatial-coordinate alignment and 4D orientation-frame alignment problems, some miscellaneous topics, and additional details of the quartic algebraic eigenvalue problem.
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Affiliation(s)
- Andrew J. Hanson
- Luddy School of Informatics, Computing, and Engineering, Indiana University, Bloomington, Indiana, USA
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7
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Soler MA, Medagli B, Semrau MS, Storici P, Bajc G, de Marco A, Laio A, Fortuna S. A consensus protocol for the in silico optimisation of antibody fragments. Chem Commun (Camb) 2019; 55:14043-14046. [PMID: 31690899 DOI: 10.1039/c9cc06182g] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We present an in silico mutagenetic protocol for improving the binding affinity of single domain antibodies (or nanobodies, VHHs). The method iteratively attempts random mutations in the interacting region of the protein and evaluates the resulting binding affinity towards the target by scoring, with a collection of scoring functions, short explicit solvent molecular dynamics trajectories of the binder-target complexes. The acceptance/rejection of each attempted mutation is carried out by a consensus decision-making algorithm, which considers all individual assessments derived from each scoring function. The method was benchmarked by evolving a single complementary determining region (CDR) of an anti-HER2 VHH hit obtained by direct panning of a phage display library. The optimised VHH mutant showed significantly enhanced experimental affinity with respect to the original VHH it matured from. The protocol can be employed as it is for the optimization of peptides, antibody fragments, and (given enough computational power) larger antibodies.
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Affiliation(s)
- Miguel A Soler
- International School for Advanced Studies (SISSA), Via Bonomea 265, 34136, Trieste, Italy.
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8
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Dongmo Foumthuim CJ, Corazza A, Esposito G, Fogolari F. Molecular dynamics simulations of β2-microglobulin interaction with hydrophobic surfaces. MOLECULAR BIOSYSTEMS 2018; 13:2625-2637. [PMID: 29051937 DOI: 10.1039/c7mb00464h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Hydrophobic surfaces are known to adsorb and unfold proteins, a process that has been studied only for a few proteins. Here we address the interaction of β2-microglobulin, a paradigmatic protein for the study of amyloidogenesis, with hydrophobic surfaces. A system with 27 copies of the protein surrounded by a model cubic hydrophobic box is studied by implicit solvent molecular dynamics simulations. Most proteins adsorb on the walls of the box without major distortions in local geometry, whereas free molecules maintain proper structures and fluctuations as observed in explicit solvent molecular dynamics simulations. The major conclusions from the simulations are as follows: (i) the adopted implicit solvent model is adequate to describe protein dynamics and thermodynamics; (ii) adsorption occurs readily and is irreversible on the simulated timescale; (iii) the regions most involved in molecular encounters and stable interactions with the walls are the same as those that are important in protein-protein and protein-nanoparticle interactions; (iv) unfolding following adsorption occurs at regions found to be flexible by both experiments and simulations; (v) thermodynamic analysis suggests a very large contribution from van der Waals interactions, whereas unfavorable electrostatic interactions are not found to contribute much to adsorption energy. Surfaces with different degrees of hydrophobicity may occur in vivo. Our simulations show that adsorption is a fast and irreversible process which is accompanied by partial unfolding. The results and the thermodynamic analysis presented here are consistent with and rationalize previous experimental work.
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9
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Fogolari F, Maloku O, Dongmo Foumthuim CJ, Corazza A, Esposito G. PDB2ENTROPY and PDB2TRENT: Conformational and Translational–Rotational Entropy from Molecular Ensembles. J Chem Inf Model 2018; 58:1319-1324. [DOI: 10.1021/acs.jcim.8b00143] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Federico Fogolari
- Dipartimento di Scienze Matematiche, Informatiche e Fisiche (DIMF), University of Udine, Via delle Scienze 206, 33100 Udine, Italy
- Istituto Nazionale Biostrutture e Biosistemi, Viale medaglie d’Oro 305, 00136 Roma, Italy
| | - Ornela Maloku
- Dipartimento di Scienze Matematiche, Informatiche e Fisiche (DIMF), University of Udine, Via delle Scienze 206, 33100 Udine, Italy
| | | | - Alessandra Corazza
- Istituto Nazionale Biostrutture e Biosistemi, Viale medaglie d’Oro 305, 00136 Roma, Italy
- Dipartimento di Area Medica (DAME), University of Udine, Piazzale Kolbe 4, 33100 Udine, Italy
| | - Gennaro Esposito
- Dipartimento di Scienze Matematiche, Informatiche e Fisiche (DIMF), University of Udine, Via delle Scienze 206, 33100 Udine, Italy
- Istituto Nazionale Biostrutture e Biosistemi, Viale medaglie d’Oro 305, 00136 Roma, Italy
- Science and Math Division, New York University at Abu Dhabi, PO Box 129188, Abu Dhabi, United Arab Emirates
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10
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Dynamics and Thermodynamics of Transthyretin Association from Molecular Dynamics Simulations. BIOMED RESEARCH INTERNATIONAL 2018; 2018:7480749. [PMID: 29967786 PMCID: PMC6008865 DOI: 10.1155/2018/7480749] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 05/06/2018] [Indexed: 12/15/2022]
Abstract
Molecular dynamics simulations are used in this work to probe the structural stability and the dynamics of engineered mutants of transthyretin (TTR), i.e., the double mutant F87M/L110M (MT-TTR) and the triple mutant F87M/L110M/S117E (3M-TTR), in relation to wild-type. Free energy analysis from end-point simulations and statistical effective energy functions are used to analyze trajectories, revealing that mutations do not have major impact on protein structure but rather on protein association, shifting the equilibria towards dissociated species. The result is confirmed by the analysis of 3M-TTR which shows dissociation within the first 10 ns of the simulation, indicating that contacts are lost at the dimer-dimer interface, whereas dimers (formed by monomers which pair to form two extended β-sheets) appear fairly stable. Overall the simulations provide a detailed view of the dynamics and thermodynamics of wild-type and mutant transthyretins and a rationale of the observed effects.
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11
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Fogolari F, Corazza A, Esposito G. Free Energy, Enthalpy and Entropy from Implicit Solvent End-Point Simulations. Front Mol Biosci 2018; 5:11. [PMID: 29473043 PMCID: PMC5809407 DOI: 10.3389/fmolb.2018.00011] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 01/25/2018] [Indexed: 11/13/2022] Open
Abstract
Free energy is the key quantity to describe the thermodynamics of biological systems. In this perspective we consider the calculation of free energy, enthalpy and entropy from end-point molecular dynamics simulations. Since the enthalpy may be calculated as the ensemble average over equilibrated simulation snapshots the difficulties related to free energy calculation are ultimately related to the calculation of the entropy of the system and in particular of the solvent entropy. In the last two decades implicit solvent models have been used to circumvent the problem and to take into account solvent entropy implicitly in the solvation terms. More recently outstanding advancement in both implicit solvent models and in entropy calculations are making the goal of free energy estimation from end-point simulations more feasible than ever before. We review briefly the basic theory and discuss the advancements in light of practical applications.
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Affiliation(s)
- Federico Fogolari
- Dipartimento di Scienze Matematiche, Informatiche e Fisiche, Universita' di Udine, Udine, Italy.,Istituto Nazionale Biostrutture e Biosistemi, Rome, Italy
| | - Alessandra Corazza
- Istituto Nazionale Biostrutture e Biosistemi, Rome, Italy.,Dipartimento di Area Medica, Universita' di Udine, Udine, Italy
| | - Gennaro Esposito
- Dipartimento di Scienze Matematiche, Informatiche e Fisiche, Universita' di Udine, Udine, Italy.,Istituto Nazionale Biostrutture e Biosistemi, Rome, Italy.,Science and Math Division, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
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12
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Ahmad M, Helms V, Kalinina OV, Lengauer T. Elucidating the energetic contributions to the binding free energy. J Chem Phys 2017; 146:014105. [PMID: 28063433 DOI: 10.1063/1.4973349] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
New exact equations are derived for the terms contributing to the binding free energy (ΔG0) of a ligand-receptor pair using our recently introduced formalism which we here call perturbation-divergence formalism (PDF). Specifically, ΔG0 equals the sum of the average of the perturbation (pertaining to new interactions) and additional dissipative terms. The average of the perturbation includes the sum of the average receptor-ligand interactions and the average of the change of solvation energies upon association. The Kullback-Leibler (KL) divergence quantifies the energetically dissipative terms, which are due to the configurational changes and, using the chain rule of KL divergence, can be decomposed into (i) dissipation due to limiting the external liberation (translation and rotation) of the ligand relative to the receptor and (ii) dissipation due to conformational (internal) changes inside the receptor and the ligand. We also identify all exactly canceling energetic terms which do not contribute to ΔG0. Furthermore, the PDF provides a new approach towards dimensionality reduction in the representation of the association process and towards relating the dynamic (high dimensional) with the thermodynamic (one-dimensional) changes.
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Affiliation(s)
- Mazen Ahmad
- Department for Computational Biology and Applied Algorithmics, Max Planck Institute for Informatics, Saarland Informatics Campus E1 4, 66123 Saarbrücken, Germany
| | - Volkhard Helms
- Center for Bioinformatics, Saarland University, 66123 Saarbrücken, Germany
| | - Olga V Kalinina
- Department for Computational Biology and Applied Algorithmics, Max Planck Institute for Informatics, Saarland Informatics Campus E1 4, 66123 Saarbrücken, Germany
| | - Thomas Lengauer
- Department for Computational Biology and Applied Algorithmics, Max Planck Institute for Informatics, Saarland Informatics Campus E1 4, 66123 Saarbrücken, Germany
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13
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Ben-Shalom IY, Pfeiffer-Marek S, Baringhaus KH, Gohlke H. Efficient Approximation of Ligand Rotational and Translational Entropy Changes upon Binding for Use in MM-PBSA Calculations. J Chem Inf Model 2017; 57:170-189. [DOI: 10.1021/acs.jcim.6b00373] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Ido Y. Ben-Shalom
- Institute
for Pharmaceutical and Medicinal Chemistry, Department of Mathematics
and Natural Sciences, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Stefania Pfeiffer-Marek
- LGCR/Pharmaceutical
Sciences Operations, Sanofi-Aventis Deutschland GmbH, Industriepark Höchst, 65926 Frankfurt am Main, Germany
| | - Karl-Heinz Baringhaus
- R&D Resources/Site Direction, Sanofi-Aventis Deutschland GmbH, Industriepark Höchst, 65926 Frankfurt am Main, Germany
| | - Holger Gohlke
- Institute
for Pharmaceutical and Medicinal Chemistry, Department of Mathematics
and Natural Sciences, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
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14
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Huggins DJ. Studying the role of cooperative hydration in stabilizing folded protein states. J Struct Biol 2016; 196:394-406. [PMID: 27633532 PMCID: PMC5131609 DOI: 10.1016/j.jsb.2016.09.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Revised: 09/03/2016] [Accepted: 09/07/2016] [Indexed: 01/19/2023]
Abstract
Understanding and modelling protein folding remains a key scientific and engineering challenge. Two key questions in protein folding are (1) why many proteins adopt a folded state and (2) how these proteins transition from the random coil ensemble to a folded state. In this paper we employ molecular dynamics simulations to address the first of these questions. Computational methods are well-placed to address this issue due to their ability to analyze systems at atomic-level resolution. Traditionally, the stability of folded proteins has been ascribed to the balance of two types of intermolecular interactions: hydrogen-bonding interactions and hydrophobic contacts. In this study, we explore a third type of intermolecular interaction: cooperative hydration of protein surface residues. To achieve this, we consider multiple independent simulations of the villin headpiece domain to quantify the contributions of different interactions to the energy of the native and fully extended states. In addition, we consider whether these findings are robust with respect to the protein forcefield, the water model, and the presence of salt. In all cases, we identify many cooperatively hydrated interactions that are transient but energetically favor the native state. Whilst further work on additional protein structures, forcefields, and water models is necessary, these results suggest a role for cooperative hydration in protein folding that should be explored further. Rational design of cooperative hydration on the protein surface could be a viable strategy for increasing protein stability.
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Affiliation(s)
- David J Huggins
- Theory of Condensed Matter Group, Cavendish Laboratory, University of Cambridge, 19 J J Thomson Avenue, Cambridge CB3 0HE, United Kingdom; Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom.
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15
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Ramsey S, Nguyen C, Salomon-Ferrer R, Walker RC, Gilson MK, Kurtzman T. Solvation thermodynamic mapping of molecular surfaces in AmberTools: GIST. J Comput Chem 2016; 37:2029-37. [PMID: 27317094 DOI: 10.1002/jcc.24417] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Revised: 04/19/2016] [Accepted: 05/17/2016] [Indexed: 02/06/2023]
Abstract
The expulsion of water from surfaces upon molecular recognition and nonspecific association makes a major contribution to the free energy changes of these processes. In order to facilitate the characterization of water structure and thermodynamics on surfaces, we have incorporated Grid Inhomogeneous Solvation Theory (GIST) into the CPPTRAJ toolset of AmberTools. GIST is a grid-based implementation of Inhomogeneous Fluid Solvation Theory, which analyzes the output from molecular dynamics simulations to map out solvation thermodynamic and structural properties on a high-resolution, three-dimensional grid. The CPPTRAJ implementation, called GIST-cpptraj, has a simple, easy-to-use command line interface, and is open source and freely distributed. We have also developed a set of open-source tools, called GISTPP, which facilitate the analysis of GIST output grids. Tutorials for both GIST-cpptraj and GISTPP can be found at ambermd.org. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Steven Ramsey
- Department of Chemistry, Lehman College, 205 W Bedford Pk Blvd, Bronx, New York, 10468.,Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, 365 5th Avenue, New York, New York, 10016
| | - Crystal Nguyen
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, California, 92093-0736
| | - Romelia Salomon-Ferrer
- San Diego Supercomputer Center, University of California San Diego, 9500 Gilman Drive MC0505, La Jolla, California, 92093-0505
| | - Ross C Walker
- San Diego Supercomputer Center, University of California San Diego, 9500 Gilman Drive MC0505, La Jolla, California, 92093-0505.,Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, California, 92093-0505
| | - Michael K Gilson
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, California, 92093-0736
| | - Tom Kurtzman
- Department of Chemistry, Lehman College, 205 W Bedford Pk Blvd, Bronx, New York, 10468.,Ph.D. Program in Biochemistry, The Graduate Center of the City University of New York, 365 5th Avenue, New York, New York, 10016.,Ph. D. Program in Chemistry, The Graduate Center of the City University of New York, 365 5th Avenue, New York, New York, 10016
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Chong SH, Ham S. New Computational Approach for External Entropy in Protein-Protein Binding. J Chem Theory Comput 2016; 12:2509-16. [PMID: 27153451 DOI: 10.1021/acs.jctc.6b00174] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Molecular recognition through the noncovalent association of biomolecules is of central importance in biology and pharmacology. Developing reliable computational methods for estimating binding thermodynamic parameters is therefore of great practical value. However, considerable uncertainty remains regarding the external entropy that is associated with the reduction in the external (positional and orientational) degrees of freedom upon complex formation. Here, we present a novel statistical mechanical method for computing the external entropy by extending the energetic approach we have developed for unimolecular processes to association processes. We find that, in contrary to what is postulated in most of the previous methods, intrinsic couplings between the internal and external degrees of freedom of bound complex cannot in general be neglected in the determination of the external entropy. Nevertheless, there exists the best choice of the external coordinates with which those couplings are minimized. With such a choice of the external coordinates, the lowest upper bound of the external entropy is obtained from a tractable expression, which serves as an estimate of the external entropy. Our method can be implemented in a straightforward manner with molecular dynamics simulations, and its applicability is demonstrated through the application to the barnase-barstar complex.
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Affiliation(s)
- Song-Ho Chong
- Department of Chemistry, Sookmyung Women's University , Cheongpa-ro 47-gil 100, Yongsan-Ku, Seoul 04310, Korea
| | - Sihyun Ham
- Department of Chemistry, Sookmyung Women's University , Cheongpa-ro 47-gil 100, Yongsan-Ku, Seoul 04310, Korea
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