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Seitz C, Deveci İ, McCammon JA. Glycosylation and Crowded Membrane Effects on Influenza Neuraminidase Stability and Dynamics. J Phys Chem Lett 2023; 14:9926-9934. [PMID: 37903229 PMCID: PMC10641874 DOI: 10.1021/acs.jpclett.3c02524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 10/18/2023] [Accepted: 10/24/2023] [Indexed: 11/01/2023]
Abstract
All protein simulations are conducted with varying degrees of simplification, oftentimes with unknown ramifications about how these simplifications affect the interpretability of the results. In this work, we investigated how protein glycosylation and lateral crowding effects modulate an array of properties characterizing the stability and dynamics of influenza neuraminidase. We constructed three systems: (1) glycosylated neuraminidase in a whole virion (i.e., crowded membrane) environment, (2) glycosylated neuraminidase in its own lipid bilayer, and (3) unglycosylated neuraminidase in its own lipid bilayer. We saw that glycans tend to stabilize the protein structure and reduce its conformational flexibility while restricting the solvent movement. Conversely, a crowded membrane environment encouraged exploration of the free energy landscape and a large-scale conformational change, while making the protein structure more compact. Understanding these effects informs what factors one must consider in attempting to recapture the desired level of physical accuracy.
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Affiliation(s)
- Christian Seitz
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093, United States
| | - İlker Deveci
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093, United States
| | - J. Andrew McCammon
- Department
of Chemistry and Biochemistry, University
of California, San Diego, La Jolla, California 92093, United States
- Department
of Pharmacology, University of California,
San Diego, La Jolla, California 92093, United States
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2
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Li Q, Kim G, Jing L, Ji X, Elmore DE, Radhakrishnan ML. Electrostatics-Based Computational Design and Experimental Analysis of Buforin II Antimicrobial Peptide Variants with Increased DNA Affinities. ACS OMEGA 2023; 8:33701-33711. [PMID: 37744799 PMCID: PMC10515408 DOI: 10.1021/acsomega.3c04023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 08/17/2023] [Indexed: 09/26/2023]
Abstract
Antimicrobial peptides (AMPs) are promising alternatives to traditional antibiotics in the treatment of bacterial infections in part due to their targeting of generic bacterial structures that make it more difficult to develop drug resistance. In this study, we introduce and implement a design workflow to develop more potent AMPs by improving their electrostatic interactions with DNA, which is a putative intracellular target. Using the existing membrane-translocating AMP buforin II (BF2) as a starting point, we use a computational workflow that integrates electrostatic charge optimization, continuum electrostatics, and molecular dynamics simulations to suggest peptide positions at which a neutral BF2 residue could be substituted with arginine to increase DNA-binding affinity either significantly or minimally, with the latter choice done to determine whether AMP binding affinity depends on charge distribution and not just overall monopole. Our analyses predicted that T1R and L8R BF2 variants would yield substantial and minimal increases in DNA-binding affinity, respectively. These predictions were validated with experimental peptide-DNA binding assays with additional computational analyses providing structural insights. Additionally, experimental measurements of antimicrobial potency showed that a design to increase DNA binding can also yield greater potency. As a whole, this study takes initial steps to support the idea that (i) a design strategy aimed to increase AMP binding affinity to DNA by focusing only on electrostatic interactions can improve AMP potency and (ii) the effect on DNA binding of increasing the overall peptide monopole via arginine substitution depends on the position of the substitution. More broadly, this design strategy is a novel way to increase the potency of other membrane-translocating AMPs that target nucleic acids.
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Affiliation(s)
- Qiao Li
- Biochemistry
Program, Wellesley College, Wellesley, Massachusetts 02481, United States
| | - Gabriela Kim
- Chemistry
Department, Wellesley College, Wellesley, Massachusetts 02481, United States
| | - Lisha Jing
- Chemistry
Department, Wellesley College, Wellesley, Massachusetts 02481, United States
| | - Xiaoxuan Ji
- Biochemistry
Program, Wellesley College, Wellesley, Massachusetts 02481, United States
| | - Donald E. Elmore
- Biochemistry
Program, Wellesley College, Wellesley, Massachusetts 02481, United States
- Chemistry
Department, Wellesley College, Wellesley, Massachusetts 02481, United States
| | - Mala L. Radhakrishnan
- Biochemistry
Program, Wellesley College, Wellesley, Massachusetts 02481, United States
- Chemistry
Department, Wellesley College, Wellesley, Massachusetts 02481, United States
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Seitz C, Deveci İ, McCammon JA. Glycosylation and Crowded Membrane Effects on Influenza Neuraminidase Stability and Dynamics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.10.556910. [PMID: 37745347 PMCID: PMC10515755 DOI: 10.1101/2023.09.10.556910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
All protein simulations are conducted with varying degrees of simplifications, oftentimes with unknown ramifications on how these simplifications affect the interpretability of the results. In this work we investigated how protein glycosylation and lateral crowding effects modulate an array of properties characterizing the stability and dynamics of influenza neuraminidase. We constructed three systems: 1) Glycosylated neuraminidase in a whole virion (i.e. crowded membrane) environment 2) Glycosylated neuraminidase in its own lipid bilayer 3) Unglycosylated neuraminidase in its own lipid bilayer. We saw that glycans tend to stabilize the protein structure and reduce its conformational flexibility while restricting solvent movement. Conversely, a crowded membrane environment encouraged exploration of the free energy landscape and a large scale conformational change while making the protein structure more compact. Understanding these effects informs what factors one must consider while attempting to recapture the desired level of physical accuracy.
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Affiliation(s)
- Christian Seitz
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California
| | - İlker Deveci
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California
| | - J. Andrew McCammon
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California
- Department of Pharmacology, University of California, San Diego, La Jolla, California
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Zhou S. Effective electrostatic forces between two neutral surfaces with surface charge separation: valence asymmetry and dielectric constant heterogeneity. Mol Phys 2022. [DOI: 10.1080/00268976.2022.2094296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- S. Zhou
- School of Physics and Electronics, Central South University, Changsha, People’s Republic of China
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5
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Yadav K, Sardana D, Shweta H, Clovis NS, Sen S. Molecular Picture of the Effect of Cosolvent Crowding on Ligand Binding and Dispersed Solvation Dynamics in G-Quadruplex DNA. J Phys Chem B 2022; 126:1668-1681. [PMID: 35170968 DOI: 10.1021/acs.jpcb.1c09349] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Understanding molecular interactions and dynamics of proteins and DNA in a cell-like crowded environment is crucial for predicting their functions within the cell. Noncanonical G-quadruplex DNA (GqDNA) structures adopt various topologies that were shown to be strongly affected by molecular crowding. However, it is unknown how such crowding affects the solvation dynamics in GqDNA. Here, we study the effect of cosolvent (acetonitrile) crowding on ligand (DAPI) solvation dynamics within human telomeric antiparallel GqDNA through direct comparison of time-resolved fluorescence Stokes shift (TRFSS) experiments and molecular dynamics (MD) simulations results. We show that ligand binding affinity to GqDNA is drastically affected by acetonitrile (ACN). Solvation dynamics probed by DAPI in GqDNA groove show dispersed dynamics from ∼100 fs to 10 ns in the absence and presence of 20% and 40% (v/v) ACN. The nature of dynamics remain similar in buffer and 20% ACN, although in 40% ACN, distinct dynamics is observed in <100 ps. MD simulations performed on GqDNA/DAPI complex reveal preferential solvation of ligand by ACN, particularly in 40% ACN. Simulated solvation time-correlation functions calculated from MD trajectories compare very well to the overall solvation dynamics of DAPI in GqDNA, observed in experiments. Linear response decomposition of simulated solvation correlation functions unfolds the origin of dispersed dynamics, showing that the slower dynamics is dominated by DNA-motion in the presence of ACN (and also by the ACN dynamics at higher concentration). However, water-DNA coupled motion controls the slow dynamics in the absence of ACN. Our data, thus, unravel a detailed molecular picture showing that though ACN crowding affect ligand binding affinity to GqDNA significantly, the overall dispersed solvation dynamics in GqDNA remain similar in the absence and the presence of 20% ACN, albeit with a small effect on the dynamics in the presence of 40% ACN due to preferential solvation of ligand by ACN.
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Affiliation(s)
- Kavita Yadav
- Spectroscopy Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Deepika Sardana
- Spectroscopy Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Him Shweta
- Spectroscopy Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Ndege Simisi Clovis
- Spectroscopy Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Sobhan Sen
- Spectroscopy Laboratory, School of Physical Sciences, Jawaharlal Nehru University, New Delhi 110067, India
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Speer SL, Stewart CJ, Sapir L, Harries D, Pielak GJ. Macromolecular Crowding Is More than Hard-Core Repulsions. Annu Rev Biophys 2022; 51:267-300. [PMID: 35239418 DOI: 10.1146/annurev-biophys-091321-071829] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cells are crowded, but proteins are almost always studied in dilute aqueous buffer. We review the experimental evidence that crowding affects the equilibrium thermodynamics of protein stability and protein association and discuss the theories employed to explain these observations. In doing so, we highlight differences between synthetic polymers and biologically relevant crowders. Theories based on hard-core interactions predict only crowding-induced entropic stabilization. However, experiment-based efforts conducted under physiologically relevant conditions show that crowding can destabilize proteins and their complexes. Furthermore, quantification of the temperature dependence of crowding effects produced by both large and small cosolutes, including osmolytes, sugars, synthetic polymers, and proteins, reveals enthalpic effects that stabilize or destabilize proteins. Crowding-induced destabilization and the enthalpic component point to the role of chemical interactions between and among the macromolecules, cosolutes, and water. We conclude with suggestions for future studies. Expected final online publication date for the Annual Review of Biophysics, Volume 51 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Shannon L Speer
- Department of Chemistry, University of North Carolina at Chapel Hill, North Carolina, USA;
| | - Claire J Stewart
- Department of Chemistry, University of North Carolina at Chapel Hill, North Carolina, USA;
| | - Liel Sapir
- Thomas Lord Department of Mechanical Engineering and Materials Science, Duke University, Durham, North Carolina, USA
| | - Daniel Harries
- Institute of Chemistry and The Fritz Haber Research Center, The Hebrew University, Jerusalem, Israel
| | - Gary J Pielak
- Department of Chemistry, University of North Carolina at Chapel Hill, North Carolina, USA; .,Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, North Carolina, USA.,Lineberger Cancer Research Center, University of North Carolina at Chapel Hill, North Carolina, USA
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Radhakrishnan ML. How to Model for a Living: The CSGF as a Catalyst for Supermodels. Comput Sci Eng 2021; 23:34-41. [DOI: 10.1109/mcse.2021.3119764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Affiliation(s)
- Michael Feig
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, United States
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Kim R, Radhakrishnan ML. Macromolecular crowding effects on electrostatic binding affinity: Fundamental insights from theoretical, idealized models. J Chem Phys 2021; 154:225101. [PMID: 34241219 DOI: 10.1063/5.0042082] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The crowded cellular environment can affect biomolecular binding energetics, with specific effects depending on the properties of the binding partners and the local environment. Often, crowding effects on binding are studied on particular complexes, which provide system-specific insights but may not provide comprehensive trends or a generalized framework to better understand how crowding affects energetics involved in molecular recognition. Here, we use theoretical, idealized molecules whose physical properties can be systematically varied along with samplings of crowder placements to understand how electrostatic binding energetics are altered through crowding and how these effects depend on the charge distribution, shape, and size of the binding partners or crowders. We focus on electrostatic binding energetics using a continuum electrostatic framework to understand effects due to depletion of a polar, aqueous solvent in a crowded environment. We find that crowding effects can depend predictably on a system's charge distribution, with coupling between the crowder size and the geometry of the partners' binding interface in determining crowder effects. We also explore the effect of crowder charge on binding interactions as a function of the monopoles of the system components. Finally, we find that modeling crowding via a lowered solvent dielectric constant cannot account for certain electrostatic crowding effects due to the finite size, shape, or placement of system components. This study, which comprehensively examines solvent depletion effects due to crowding, complements work focusing on other crowding aspects to help build a holistic understanding of environmental impacts on molecular recognition.
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Affiliation(s)
- Rachel Kim
- Department of Chemistry, Wellesley College, Wellesley, Massachusetts 02481, USA
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