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Bae S, Kim JS. Potential of Mean Force for DNA Wrapping Around a Cationic Nanoparticle. J Chem Theory Comput 2021; 17:7952-7961. [PMID: 34792353 DOI: 10.1021/acs.jctc.1c00797] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Sharp bending and wrapping of DNA around proteins and nanoparticles (NPs) has been of extensive research interest. Here, we present the potential of mean force (PMF) for wrapping a DNA double helix around a cationic NP using coarse-grained models of a double-stranded DNA and a cationic NP. Starting from a NP wrapped around by DNA, the PMF was calculated along the distance between the center of the NP and one end of the DNA molecule. A relationship between the distance and the extent of DNA wrapping is used to calculate the PMF as a function of DNA wrapping around a NP. In particular, the PMF was compared for two DNA sequences of (AT)25/(AT)25 and (AC)25/(GT)25, for which the persistence lengths are different by ∼10 nm. The simulation results provide solid evidence of the thermodynamic preference for complex formation of a cationic NP with more flexible DNA over the less flexible DNA. Furthermore, we estimated the elastic energy of DNA bending, which was in good order-of-magnitude agreement with the theoretical prediction of elastic rods. This work suggests that the variation of sequence-dependent DNA flexibility can be utilized in DNA nanotechnologies, in which the position and dynamics of NPs are regulated on large-scale DNA structures, or the structural transformation of DNA is triggered by the sequence-dependent binding of NPs.
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Affiliation(s)
- Sehui Bae
- Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 03760, Republic of Korea
| | - Jun Soo Kim
- Department of Chemistry and Nanoscience, Ewha Womans University, Seoul 03760, Republic of Korea
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2
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Róg T, Girych M, Bunker A. Mechanistic Understanding from Molecular Dynamics in Pharmaceutical Research 2: Lipid Membrane in Drug Design. Pharmaceuticals (Basel) 2021; 14:1062. [PMID: 34681286 PMCID: PMC8537670 DOI: 10.3390/ph14101062] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 11/17/2022] Open
Abstract
We review the use of molecular dynamics (MD) simulation as a drug design tool in the context of the role that the lipid membrane can play in drug action, i.e., the interaction between candidate drug molecules and lipid membranes. In the standard "lock and key" paradigm, only the interaction between the drug and a specific active site of a specific protein is considered; the environment in which the drug acts is, from a biophysical perspective, far more complex than this. The possible mechanisms though which a drug can be designed to tinker with physiological processes are significantly broader than merely fitting to a single active site of a single protein. In this paper, we focus on the role of the lipid membrane, arguably the most important element outside the proteins themselves, as a case study. We discuss work that has been carried out, using MD simulation, concerning the transfection of drugs through membranes that act as biological barriers in the path of the drugs, the behavior of drug molecules within membranes, how their collective behavior can affect the structure and properties of the membrane and, finally, the role lipid membranes, to which the vast majority of drug target proteins are associated, can play in mediating the interaction between drug and target protein. This review paper is the second in a two-part series covering MD simulation as a tool in pharmaceutical research; both are designed as pedagogical review papers aimed at both pharmaceutical scientists interested in exploring how the tool of MD simulation can be applied to their research and computational scientists interested in exploring the possibility of a pharmaceutical context for their research.
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Affiliation(s)
- Tomasz Róg
- Department of Physics, University of Helsinki, 00014 Helsinki, Finland;
| | - Mykhailo Girych
- Department of Physics, University of Helsinki, 00014 Helsinki, Finland;
| | - Alex Bunker
- Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, 00014 Helsinki, Finland;
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3
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Wang X, Limpouchová Z, Procházka K, Liu Y, Min Y. Phase equilibria and conformational behavior of dendrimers in porous media: Towards chromatographic analysis of dendrimers. J Colloid Interface Sci 2021; 608:830-839. [PMID: 34689112 DOI: 10.1016/j.jcis.2021.09.177] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 09/16/2021] [Accepted: 09/27/2021] [Indexed: 02/08/2023]
Abstract
HYPOTHESIS The intricate entropy-enthalpy interplay of dendrimers confined in pores affects their conformation and retention in the porous stationary phase. This work aims at providing important insights into its impacts on partitioning and chromatographic separation in both size-exclusion chromatography (SEC) and interaction chromatography (IC) regimes. SIMULATIONS Using Monte Carlo (MC) simulations, we investigated the bulk-pore phase equilibria and the conformational behavior of flexible dendrimers differing in generation, in spacer length and in fraction of modified terminal groups interacting differently with pore walls than the majority building units. FINDINGS With increasing interaction strength, a distinct transition from a roughly spherical shape caused by simultaneous interactions with two walls to an ellipsoidal (or even disklike) conformation tenaciously adhering to only one wall was observed for moderately confined dendrimers. The strongly deformed dendrimers subjected to severe confinement gain high energy and the samples differing in the degree of modification become chromatographically discernable thanks to large energy differences. Consequently, our results suggest that the column fillings with fairly narrow pores which are ineffective in SEC, are highly efficient separation media for dendrimer studies by IC above the critical adsorption point (CAP). Overall, our simulations reveal useful information for advancing and optimizing experimental liquid chromatography studies of dendrimers.
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Affiliation(s)
- Xiu Wang
- School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, Guangdong, China.
| | - Zuzana Limpouchová
- Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova 8, Prague 2 128 43, Czech Republic.
| | - Karel Procházka
- Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova 8, Prague 2 128 43, Czech Republic.
| | - Yidong Liu
- School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, Guangdong, China.
| | - Yonggang Min
- School of Materials and Energy, Guangdong University of Technology, Guangzhou 510006, Guangdong, China.
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Fernandes G, Pandey A, Kulkarni S, Mutalik SP, Nikam AN, Seetharam RN, Kulkarni SS, Mutalik S. Supramolecular dendrimers based novel platforms for effective oral delivery of therapeutic moieties. J Drug Deliv Sci Technol 2021. [DOI: 10.1016/j.jddst.2021.102647] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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5
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Bae S, Oh I, Yoo J, Kim JS. Effect of DNA Flexibility on Complex Formation of a Cationic Nanoparticle with Double-Stranded DNA. ACS OMEGA 2021; 6:18728-18736. [PMID: 34337212 PMCID: PMC8319935 DOI: 10.1021/acsomega.1c01709] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 07/05/2021] [Indexed: 06/13/2023]
Abstract
We present extensive molecular dynamics simulations of a cationic nanoparticle and a double-stranded DNA molecule to discuss the effect of DNA flexibility on the complex formation of a cationic nanoparticle with double-stranded DNA. Martini coarse-grained models were employed to describe double-stranded DNA molecules with two different flexibilities and cationic nanoparticles with three different electric charges. As the electric charge of a cationic nanoparticle increases, the degree of DNA bending increases, eventually leading to the wrapping of DNA around the nanoparticle at high electric charges. However, a small increase in the persistence length of DNA by 10 nm requires a cationic nanoparticle with a markedly increased electric charge to bend and wrap DNA around. Thus, a more flexible DNA molecule bends and wraps around a cationic nanoparticle with an intermediate electric charge, whereas a less flexible DNA molecule binds to a nanoparticle with the same electric charge without notable bending. This work provides solid evidence that a small difference in DNA flexibility (as small as 10 nm in persistence length) has a substantial influence on the complex formation of DNA with proteins from a biological perspective and suggests that the variation of sequence-dependent DNA flexibility can be utilized in DNA nanotechnology as a new tool to manipulate the structure of DNA molecules mediated by nanoparticle binding.
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Affiliation(s)
- Sehui Bae
- Department
of Chemistry and Nanoscience, Ewha Womans
University, Seoul 03760, Republic of Korea
| | - Inrok Oh
- LG
Chem Ltd., LG Science Park, Seoul 07796, Republic of Korea
| | - Jejoong Yoo
- Department
of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea
| | - Jun Soo Kim
- Department
of Chemistry and Nanoscience, Ewha Womans
University, Seoul 03760, Republic of Korea
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6
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Bunker A, Róg T. Mechanistic Understanding From Molecular Dynamics Simulation in Pharmaceutical Research 1: Drug Delivery. Front Mol Biosci 2020; 7:604770. [PMID: 33330633 PMCID: PMC7732618 DOI: 10.3389/fmolb.2020.604770] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 11/02/2020] [Indexed: 12/12/2022] Open
Abstract
In this review, we outline the growing role that molecular dynamics simulation is able to play as a design tool in drug delivery. We cover both the pharmaceutical and computational backgrounds, in a pedagogical fashion, as this review is designed to be equally accessible to pharmaceutical researchers interested in what this new computational tool is capable of and experts in molecular modeling who wish to pursue pharmaceutical applications as a context for their research. The field has become too broad for us to concisely describe all work that has been carried out; many comprehensive reviews on subtopics of this area are cited. We discuss the insight molecular dynamics modeling has provided in dissolution and solubility, however, the majority of the discussion is focused on nanomedicine: the development of nanoscale drug delivery vehicles. Here we focus on three areas where molecular dynamics modeling has had a particularly strong impact: (1) behavior in the bloodstream and protective polymer corona, (2) Drug loading and controlled release, and (3) Nanoparticle interaction with both model and biological membranes. We conclude with some thoughts on the role that molecular dynamics simulation can grow to play in the development of new drug delivery systems.
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Affiliation(s)
- Alex Bunker
- Division of Pharmaceutical Biosciences, Drug Research Program, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Tomasz Róg
- Department of Physics, University of Helsinki, Helsinki, Finland
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7
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Abstract
Using fully atomistic molecular dynamics simulation that are several hundred nanoseconds long, we demonstrate the pH-controlled sponge action of PAMAM dendrimer. We show how at varying pH levels, the PAMAM dendrimer acts as a wet sponge; at neutral or low pH levels, the dendrimer expands noticeably and the interior of the dendrimer opens up to host several hundreds to thousands of water molecules depending on the generation number. Increasing the pH (i.e., going from low pH to high pH) leads to the collapse of the dendrimer size, thereby expelling the inner water, which mimics the ‘sponge’ action. As the dendrimer size swells up at a neutral pH or low pH due to the electrostatic repulsion between the primary and tertiary amines that are protonated at this pH, there is dramatic increase in the available solvent accessible surface area (SASA), as well as solvent accessible volume (SAV).
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Affiliation(s)
- Prabal K. Maiti
- Center for Condensed Matter Theory, Department of Physics, Bangalore, India, 560012
- Center for Condensed Matter Theory, Department of Physics, Bangalore, India, 560012
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Abstract
Gene therapy is an important therapeutic strategy in the treatment of a wide range of genetic disorders. Polymers forming stable complexes with nucleic acids (NAs) are non-viral gene carriers. The self-assembly of polymers and nucleic acids is typically a complex process that involves many types of interaction at different scales. Electrostatic interaction, hydrophobic interaction, and hydrogen bonds are three important and prevalent interactions in the polymer/nucleic acid system. Electrostatic interactions and hydrogen bonds are the main driving forces for the condensation of nucleic acids, while hydrophobic interactions play a significant role in the cellular uptake and endosomal escape of polymer-nucleic acid complexes. To design high-efficiency polymer candidates for the DNA and siRNA delivery, it is necessary to have a detailed understanding of the interactions between them in solution. In this chapter, we survey the roles of the three important interactions between polymers and nucleic acids during the formation of polyplexes and summarize recent understandings of the linear polyelectrolyte-NA interactions and dendrimer-NA interactions. We also review recent progress optimizing the gene delivery system by tuning these interactions.
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9
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Binding of single stranded nucleic acids to cationic ligand functionalized gold nanoparticles. Biointerphases 2016; 11:04B305. [PMID: 27835922 DOI: 10.1116/1.4966653] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The interactions of nanoparticles (NPs) with single stranded nucleic acids (NAs) have important implications in gene delivery, and nanotechnological and biomedical applications. Here, the complexation of cationic ligand functionalized gold nanoparticles with single stranded deoxyribose nucleic acid (DNA) and ribonucleic acid (RNA) are examined using all atom molecular dynamics simulations. The results indicated that complexation depends mostly on charge of nanoparticle, and, to lesser extent, sequence and type of nucleic acid. For cationic nanoparticles, electrostatic interactions between charged ligands and the nucleic acid backbone dominate binding regardless of nanoparticle charge. Highly charged nanoparticles bind more tightly and cause compaction of the single-stranded NAs through disruption of intrastrand π-π stacking and hydrogen bonding. However, poly-purine strands (polyA-DNA, polyA-RNA) show less change in structure than poly-pyrimidine strands (polyT-DNA, polyU-RNA). Overall, the results show that control over ssNA structure may be achieved with cationic NPs with a charge of more than 30, but the extent of the structural changes depends on sequence.
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10
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Bunker A, Magarkar A, Viitala T. Rational design of liposomal drug delivery systems, a review: Combined experimental and computational studies of lipid membranes, liposomes and their PEGylation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2334-2352. [DOI: 10.1016/j.bbamem.2016.02.025] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 02/09/2016] [Accepted: 02/10/2016] [Indexed: 01/22/2023]
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11
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Ramezanpour M, Leung SSW, Delgado-Magnero KH, Bashe BYM, Thewalt J, Tieleman DP. Computational and experimental approaches for investigating nanoparticle-based drug delivery systems. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:1688-709. [PMID: 26930298 DOI: 10.1016/j.bbamem.2016.02.028] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 02/20/2016] [Accepted: 02/23/2016] [Indexed: 12/21/2022]
Abstract
Most therapeutic agents suffer from poor solubility, rapid clearance from the blood stream, a lack of targeting, and often poor translocation ability across cell membranes. Drug/gene delivery systems (DDSs) are capable of overcoming some of these barriers to enhance delivery of drugs to their right place of action, e.g. inside cancer cells. In this review, we focus on nanoparticles as DDSs. Complementary experimental and computational studies have enhanced our understanding of the mechanism of action of nanocarriers and their underlying interactions with drugs, biomembranes and other biological molecules. We review key biophysical aspects of DDSs and discuss how computer modeling can assist in rational design of DDSs with improved and optimized properties. We summarize commonly used experimental techniques for the study of DDSs. Then we review computational studies for several major categories of nanocarriers, including dendrimers and dendrons, polymer-, peptide-, nucleic acid-, lipid-, and carbon-based DDSs, and gold nanoparticles. This article is part of a Special Issue entitled: Membrane Proteins edited by J.C. Gumbart and Sergei Noskov.
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Affiliation(s)
- M Ramezanpour
- Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - S S W Leung
- Department of Physics, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - K H Delgado-Magnero
- Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - B Y M Bashe
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - J Thewalt
- Department of Physics, Simon Fraser University, Burnaby, BC V5A 1S6, Canada; Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 1S6, Canada
| | - D P Tieleman
- Centre for Molecular Simulation, Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
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12
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Abstract
We investigate the electrostatics, energetics, and dynamics of dendrimer-DNA interactions that mimic protein-DNA complexes as a means to design facilitated mechanisms by which dendrimers can slide and search DNA for targets. By using all-atom molecular dynamics simulations, we calculated the free energy profiles of dendrimer-binding around the DNA via umbrella sampling. We also calculated electrostatic interaction maps in comparison to proteins, as well as the dynamical changes induced by DNA-dendrimer interactions via NMR-measurable order parameters. Our results show that for dendrimers to go around DNA, there is a free-energy barrier of 8.5 kcal/mol from the DNA major groove to DNA minor groove, with a minimum in the major groove. This barrier height makes it unlikely for an all-amine dendrimer to slide along DNA longitudinally, but following a helical path may be possible along the major groove. Comparison of the nonbonded interaction energy and the interaction free-energy profiles reveal a considerable entropic cost as the dendrimer binds to DNA. This is also supported by the mobility patterns obtained from NMR-measurable order parameter values, which show a decreased mobility of the dendrimer N-H bond vectors in the DNA-binding mode.
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Affiliation(s)
- Emel Ficici
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Ioan Andricioaei
- Department of Chemistry, University of California, Irvine, California 92697, United States
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13
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Bellini RG, Guimarães AP, Pacheco MAC, Dias DM, Furtado VR, de Alencastro RB, Horta BAC. Association of the anti-tuberculosis drug rifampicin with a PAMAM dendrimer. J Mol Graph Model 2015; 60:34-42. [PMID: 26093506 DOI: 10.1016/j.jmgm.2015.05.012] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Revised: 05/03/2015] [Accepted: 05/22/2015] [Indexed: 12/19/2022]
Abstract
The association of the anti-tuberculosis drug rifampicin (RIF) with a 4th-generation poly(amidoamine) (G4-PAMAM) dendrimer was investigated by means of molecular dynamics simulations. The RIF load capacity was estimated to be around 20 RIF per G4-PAMAM at neutral pH. The complex formed by 20 RIF molecules and the dendrimer (RIF20-PAMAM) was subjected to 100 ns molecular dynamics (MD) simulations at two different pH conditions (neutral and acidic). The complex was found to be significantly more stable in the simulation at neutral pH compared to the simulation at low pH in which the RIF molecules were rapidly and almost simultaneously expelled to the solvent bulk. The high stability of the RIF-PAMAM complex under physiological pH and the rapid release of RIF molecules under acidic medium provide an interesting switch for drug targeting since the Mycobacterium resides within acidic domains of the macrophage. Altogether, these results suggest that, at least in terms of stability and pH-dependent release, PAMAM-like dendrimers may be considered suitable drug delivery systems for RIF and derivatives.
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Affiliation(s)
| | - Ana P Guimarães
- Departamento de Química, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Marco A C Pacheco
- Departamento de Engenharia Elétrica, PUC-Rio, Rio de Janeiro, Brazil
| | - Douglas M Dias
- Departamento de Engenharia Elétrica, PUC-Rio, Rio de Janeiro, Brazil
| | - Vanessa R Furtado
- Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Bruno A C Horta
- Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
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14
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Dzieciuch M, Rissanen S, Szydłowska N, Bunker A, Kumorek M, Jamróz D, Vattulainen I, Nowakowska M, Róg T, Kepczynski M. PEGylated Liposomes as Carriers of Hydrophobic Porphyrins. J Phys Chem B 2015; 119:6646-57. [DOI: 10.1021/acs.jpcb.5b01351] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Monika Dzieciuch
- Faculty
of Chemistry, Jagiellonian University, Krakow 31-007, Poland
| | - Sami Rissanen
- Department
of Physics, Tampere University of Technology, Tampere 33720, Finland
| | | | - Alex Bunker
- Centre
for Drug Research, Faculty of Pharmacy, University of Helsinki, Helsinki 00100, Finland
| | - Marta Kumorek
- Faculty
of Chemistry, Jagiellonian University, Krakow 31-007, Poland
| | - Dorota Jamróz
- Faculty
of Chemistry, Jagiellonian University, Krakow 31-007, Poland
| | - Ilpo Vattulainen
- Department
of Physics, Tampere University of Technology, Tampere 33720, Finland
- MEMPHYS-Center
for Biomembrane Physics, University of Southern Denmark, Odense 5230, Denmark
| | - Maria Nowakowska
- Faculty
of Chemistry, Jagiellonian University, Krakow 31-007, Poland
| | - Tomasz Róg
- Department
of Physics, Tampere University of Technology, Tampere 33720, Finland
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15
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Pavan GM. Modeling the Interaction between Dendrimers and Nucleic Acids: a Molecular Perspective through Hierarchical Scales. ChemMedChem 2014; 9:2623-31. [DOI: 10.1002/cmdc.201402280] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Indexed: 01/02/2023]
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16
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Li NK, Kim HS, Nash JA, Lim M, Yingling YG. Progress in molecular modelling of DNA materials. MOLECULAR SIMULATION 2014. [DOI: 10.1080/08927022.2014.913792] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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17
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Yang CC, Huang YC, Chen CY, Su CJ, Chen HL, Ivanov VA. Structure of the Electrostatic Complex of DNA with Cationic Dendrimer of Intermediate Generation: The Role of Counterion Entropy. Macromolecules 2014. [DOI: 10.1021/ma500546h] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Cheng-Che Yang
- Department
of Chemical Engineering and Frontier Research Center on Fundamental
and Applied Sciences of Matters, National Tsing Hua University, Hsin-Chu 30013, Taiwan
| | - Yen-Chih Huang
- National Synchrotron Radiation Research Center, Hsin-Chu, Taiwan
| | - Chun-Yu Chen
- National Synchrotron Radiation Research Center, Hsin-Chu, Taiwan
| | - Chun-Jen Su
- National Synchrotron Radiation Research Center, Hsin-Chu, Taiwan
| | - Hsin-Lung Chen
- Department
of Chemical Engineering and Frontier Research Center on Fundamental
and Applied Sciences of Matters, National Tsing Hua University, Hsin-Chu 30013, Taiwan
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18
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Simanek EE, Enciso AE, Pavan GM. Computational design principles for the discovery of bioactive dendrimers: [s]-triazines and other examples. Expert Opin Drug Discov 2013; 8:1057-69. [PMID: 23826946 DOI: 10.1517/17460441.2013.813479] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Chemistry yields dendrimers of many classes and compositions. Translating this synthetic success to bioactivity is significantly aided by the use of computational modeling and our knowledge of the three-dimensional shapes of these macromolecules. AREAS COVERED This review discusses the lessons learned during the investigations of [s]-triazine dendrimers. Specifically, the article focuses on the evolving role that computational models have taken in the exploration of these macromolecules. These lessons, furthermore, can be generalized across many dendrimer classes. EXPERT OPINION Computational models and the resulting structural data from molecular dynamics simulations provide insights into: shape, solvent penetration, shielding of biolabile linkers, and the density of hydrophobic patches. These models have evolved from artistic representations, through bases for rationalization, to hypothesis-generating tools that drive synthesis. With further advances expected in both software and hardware the answer to the question, 'What does a specific dendrimer look like in solution?' is becoming increasingly clear. Moreover, the authors believe that answer to this question lies at the heart of the design of bioactive dendrimers.
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Affiliation(s)
- Eric E Simanek
- Texas Christian University, Department of Chemistry , 2800 South University Drive, Fort Worth, TX 76129, USA.
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19
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Feng Z, Hou T, Li Y. Transport of nucleosides in the vcCNT facilitated by sodium gradients from molecular dynamics simulations. MOLECULAR BIOSYSTEMS 2013; 9:2142-53. [PMID: 23722168 DOI: 10.1039/c3mb70126c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nucleosides are required for DNA and RNA synthesis, and the nucleoside adenosine has a function in a variety of signaling processes. Nucleosides require a specialized class of integral membrane proteins, known as nucleoside transporters (NTs), for specific transport across cell membranes. NTs are also important determinants for the transport of nucleoside-derived drugs across cell membranes. Recently, the crystal structure of the vcCNT (Vibrio cholerae Concentrative Nucleoside Transporter) was reported. Here we perform molecular dynamics (MD) simulations for the vcCNT structure in the presence of various sodium gradients, since CNTs are sodium-coupled transporters. The results highlight the important role of sodium bound to the vcCNT in the transport of uridine. Our MD simulations show that, without NaCl, uridine remains stable in the binding pocket of the vcCNT. In the presence of 20 mM NaCl, uridine moves from the binding pocket and approaches the entrance of the intracellular side. In the presence of 100 mM NaCl, uridine passes through most part of the entrance and approaches the intracellular side. The polar/charged amino acids in the binding pocket are important in the transport process. They first "fix" the ribose and allow the uracil base of uridine to approach the entrance of the intracellular side, and then "release" the ribose to allow uridine to move freely into the intracellular side coupled with the movement of sodium ions and HP1b. Finally, we propose a detailed mechanism of the nucleoside transport from the binding pocket to the intracellular side of the vcCNT.
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Affiliation(s)
- Zhiwei Feng
- Institute of Functional Nano & Soft Materials FUNSOM and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, Jiangsu 215123, China
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