1
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Nguyen SV, Levintov L, Planalp RP, Vashisth H. Interactions and Transport of a Bioconjugated Peptide Targeting the Mitomembrane. Bioconjug Chem 2024; 35:371-380. [PMID: 38404183 PMCID: PMC10961729 DOI: 10.1021/acs.bioconjchem.3c00561] [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: 12/21/2023] [Revised: 02/10/2024] [Accepted: 02/13/2024] [Indexed: 02/27/2024]
Abstract
The Szeto-Schiller (SS) peptides are a subclass of cell-penetrating peptides that can specifically target mitochondria and mediate conditions caused by mitochondrial dysfunction. In this work, we constructed an iron-chelating SS peptide and studied its interaction with a mitochondrial-mimicking membrane using atomistic molecular dynamics (MD) simulations. We report that the peptide/membrane interaction is thermodynamically favorable, and the localization of the peptide to the membrane is driven by electrostatic interactions between the cationic residues and the anionic phospholipid headgroups. The insertion of the peptide into the membrane is driven by hydrophobic interactions between the aromatic side chains in the peptide and the lipid acyl tails. We also probed the translocation of the peptide across the membrane by applying nonequilibrium steered MD simulations and resolved the translocation pathway, free energy profile, and metastable states. We explored four distinct orientations of the peptide along the translocation pathway and found that one orientation was energetically more favorable than the other orientations. We tested a significantly slower pulling velocity on the most thermodynamically favorable system and compared metastable states during peptide translocation. We found that the peptide can optimize hydrophobic interactions with the membrane by having aromatic side chains interacting with the lipid acyl tails instead of forming π-π interactions with each other. The mechanistic insights emerging from our work will potentially facilitate improved peptide design with enhanced activity.
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Affiliation(s)
- Son V. Nguyen
- Department
of Chemistry, University of New Hampshire, Durham, New Hampshire 03824, United States
| | - Lev Levintov
- Department
of Chemical Engineering & Bioengineering, University of New Hampshire, Durham, New Hampshire 03824, United States
| | - Roy P. Planalp
- Department
of Chemistry, University of New Hampshire, Durham, New Hampshire 03824, United States
| | - Harish Vashisth
- Department
of Chemistry, University of New Hampshire, Durham, New Hampshire 03824, United States
- Department
of Chemical Engineering & Bioengineering, University of New Hampshire, Durham, New Hampshire 03824, United States
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2
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Ivánczi M, Balogh B, Kis L, Mándity I. Molecular Dynamics Simulations of Drug-Conjugated Cell-Penetrating Peptides. Pharmaceuticals (Basel) 2023; 16:1251. [PMID: 37765059 PMCID: PMC10535489 DOI: 10.3390/ph16091251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 08/08/2023] [Accepted: 08/11/2023] [Indexed: 09/29/2023] Open
Abstract
Cell-penetrating peptides (CPPs) are small peptides capable of translocating through biological membranes carrying various attached cargo into cells and even into the nucleus. They may also participate in transcellular transport. Our in silico study intends to model several peptides and their conjugates. We have selected three CPPs with a linear backbone, including penetratin, a naturally occurring oligopeptide; two of its modified sequence analogues (6,14-Phe-penetratin and dodeca-penetratin); and three natural CPPs with a cyclic backbone: Kalata B1, the Sunflower trypsin inhibitor 1 (SFT1), and Momordica cochinchinensis trypsin inhibitor II (MCoTI-II). We have also built conjugates with the small-molecule drug compounds doxorubicin, zidovudine, and rasagiline for each peptide. Molecular dynamics (MD) simulations were carried out with explicit membrane models. The analysis of the trajectories showed that the interaction of penetratin with the membrane led to spectacular rearrangements in the secondary structure of the peptide, while cyclic peptides remained unchanged due to their high conformational stability. Membrane-peptide and membrane-conjugate interactions have been identified and compared. Taking into account well-known examples from the literature, our simulations demonstrated the utility of computational methods for CPP complexes, and they may contribute to a better understanding of the mechanism of penetration, which could serve as the basis for delivering conjugated drug molecules to their intracellular targets.
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Affiliation(s)
- Márton Ivánczi
- Institute of Organic Chemistry, Semmelweis University, Hőgyes Endre Utca 7., H-1092 Budapest, Hungary (L.K.)
| | - Balázs Balogh
- Institute of Organic Chemistry, Semmelweis University, Hőgyes Endre Utca 7., H-1092 Budapest, Hungary (L.K.)
| | - Loretta Kis
- Institute of Organic Chemistry, Semmelweis University, Hőgyes Endre Utca 7., H-1092 Budapest, Hungary (L.K.)
| | - István Mándity
- Institute of Organic Chemistry, Semmelweis University, Hőgyes Endre Utca 7., H-1092 Budapest, Hungary (L.K.)
- Artificial Transporters Research Group, Institute of Materials and Environmental Chemistry, Research Centre for Natural Sciences, Magyar Tudósok Körútja 2., H-1117 Budapest, Hungary
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3
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Spoorthi Shetty S, Halagali P, Johnson AP, Spandana KMA, Gangadharappa HV. Oral insulin delivery: Barriers, strategies, and formulation approaches: A comprehensive review. Int J Biol Macromol 2023:125114. [PMID: 37263330 DOI: 10.1016/j.ijbiomac.2023.125114] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 05/23/2023] [Accepted: 05/24/2023] [Indexed: 06/03/2023]
Abstract
Diabetes Mellitus is characterized by a hyperglycemic condition which can either be caused by the destruction of the beta cells or by the resistance developed against insulin in the cells. Insulin is a peptide hormone that regulates the metabolism of carbohydrates, proteins, and fats. Type 1 Diabetes Mellitus needs the use of Insulin for efficient management. However invasive methods of administration may lead to reduced adherence by the patients. Hence there is a need for a non-invasive method of administration. Oral Insulin has several merits over the conventional method including patient compliance, and reduced cost, and it also mimics endogenous insulin and hence reaches the liver by the portal vein at a higher concentration and thereby showing improved efficiency. However oral Insulin must pass through several barriers in the gastrointestinal tract. Some strategies that could be utilized to bypass these barriers include the use of permeation enhancers, absorption enhancers, use of suitable polymers, use of suitable carriers, and other agents. Several formulation types have been explored for the oral delivery of Insulin like hydrogels, capsules, tablets, and patches which have been described briefly by the article. A lot of attempts have been made for developing oral insulin delivery however none of them have been commercialized due to numerous shortcomings. Currently, there are several formulations from the companies that are still in the clinical phase, the success or failure of some is yet to be seen in the future.
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Affiliation(s)
- S Spoorthi Shetty
- Department of Pharmaceutics, JSS College of Pharmacy, JSS Academy of Higher Education and Research, Mysuru 570015, Karnataka, India
| | - Praveen Halagali
- Department of Pharmaceutics, JSS College of Pharmacy, JSS Academy of Higher Education and Research, Mysuru 570015, Karnataka, India
| | - Asha P Johnson
- Department of Pharmaceutics, JSS College of Pharmacy, JSS Academy of Higher Education and Research, Mysuru 570015, Karnataka, India
| | - K M Asha Spandana
- Department of Pharmaceutics, JSS College of Pharmacy, JSS Academy of Higher Education and Research, Mysuru 570015, Karnataka, India
| | - H V Gangadharappa
- Department of Pharmaceutics, JSS College of Pharmacy, JSS Academy of Higher Education and Research, Mysuru 570015, Karnataka, India.
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4
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Xiao X, Ji J, Wang H, Nangia S, Wang H, Libera M. Self-Defensive Antimicrobial Surfaces Using Polymyxin-Loaded Poly(styrene sulfonate) Microgels. ACS Biomater Sci Eng 2022; 8:4827-4837. [PMID: 36256955 DOI: 10.1021/acsbiomaterials.2c00783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Self-defensive antimicrobial surfaces are of interest because they can inhibit bacterial colonization while minimizing unnecessary antimicrobial release in the absence of a bacterial challenge. One self-defensive approach uses self-assembly to first deposit a submonolayer coating of polyelectrolyte microgels and subsequently load those microgels by complexation with small-molecule antimicrobials. The microgel/antimicrobial complexation strength is a key parameter that controls the ability of the antimicrobial both to remain sequestered within the microgels when exposed to medium and to release in response to a bacterial challenge. Here we study the relative complexation strengths of two FDA-approved cationic antibiotics─colistin (polymyxin E) and polymyxin B─with microgels of poly(styrene sulfonate) (PSS). These polymyxins are similar cyclic polypeptides with +5 charge at pH 7.4. However, polymyxin B substitutes an aromatic ring for a dimethyl moiety in colistin, and this aromaticity can influence complexation via π and hydrophobic interactions. Coarse-grained molecular dynamics shows that the free-energy change associated with polymyxin B/PSS complexation is more negative than that of colistin/PSS complexation. Experimentally, in situ optical microscopy of microgel deswelling shows that both antibiotics load quickly from low-ionic-strength phosphate buffer. The enhanced polymyxin B/PSS complexation strength is then manifested by subsequent exposure to flowing antibiotic-free buffer with varying NaCl concentration. Microgels loaded with polymyxin B remain stably deswollen to higher salt concentrations than do colistin/PSS microgels. Importantly, exposing loaded microgels to E. coli in nutrient-free-flowing phosphate buffer shows that bacteria are killed by physical contact with the loaded microgels consistent with the contact-transfer mechanism of self-defensiveness. In vitro culture experiments show that these same surfaces, nevertheless, support the adhesion, spreading and proliferation of human fetal osteoblasts. These findings suggest a pathway to create a self-defensive antimicrobial surface effective under physiological conditions based on the nonmetabolic bacteria-triggered release of FDA-approved antibiotics.
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Affiliation(s)
- Xixi Xiao
- Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey07030, United States
| | - Jingjing Ji
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York13244, United States
| | - Haoyu Wang
- Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, New Jersey07030, United States
| | - Shikha Nangia
- Department of Biomedical and Chemical Engineering, Syracuse University, Syracuse, New York13244, United States
| | - Hongjun Wang
- Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, New Jersey07030, United States.,Center for Healthcare Innovation, Stevens Institute of Technology, Hoboken, New Jersey07030, United States
| | - Matthew Libera
- Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey07030, United States
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5
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Povilaitis SC, Fathizadeh A, Kogan M, Elber R, Webb LJ. Design of Peptides for Membrane Insertion: The Critical Role of Charge Separation. J Phys Chem B 2022; 126:6454-6463. [PMID: 35997537 PMCID: PMC9541189 DOI: 10.1021/acs.jpcb.2c04615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A physical understanding of membrane permeation and translocation by small, positively charged molecules can illuminate cell penetrating peptide mechanisms of entry and inform drug design. We have previously investigated the permeation of the doubly charged peptide WKW and proposed a defect-assisted permeation mechanism where a small molecule with +2 charge can achieve a metastable state spanning the bilayer by forming a membrane defect with charges stabilized by phospholipid phosphate groups. Here, we investigate the membrane permeation of two doubly charged peptides, WWK and WWWK, with charges separated by different lengths. Through complementary experiments and molecular dynamics simulations, we show that membrane permeation was an order of magnitude more favorable when charges were separated by an ∼2-3 Å greater distance on WWWK compared to WWK. These results agree with the previously proposed defect-assisted permeation mechanism, where a greater distance between positive charges would require a less extreme membrane defect to stabilize the membrane-spanning metastable state. We discuss the implications of these results in understanding the membrane permeation of cell-penetrating peptides and other small, positively charged membrane permeants.
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Affiliation(s)
- Sydney C. Povilaitis
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, United States
| | - Arman Fathizadeh
- Oden Institute for Computational Engineering and Science, University of Texas at Austin, Austin, Texas 78712, United States
| | - Molly Kogan
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, United States
| | - Ron Elber
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, United States
- Oden Institute for Computational Engineering and Science, University of Texas at Austin, Austin, Texas 78712, United States
| | - Lauren J. Webb
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, United States
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6
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Cell-penetrating peptide for targeted macromolecule delivery into plant chloroplasts. Appl Microbiol Biotechnol 2022; 106:5249-5259. [PMID: 35821432 DOI: 10.1007/s00253-022-12053-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 06/24/2022] [Accepted: 06/26/2022] [Indexed: 12/30/2022]
Abstract
Reports on chloroplast-targeted protein delivery using cell-penetrating peptides are scarce. In this study, a novel peptide-based macromolecule delivery strategy targeting chloroplasts was successfully developed in wheat mesophyll protoplasts. A peptide derived from the signal sequence of the chloroplast-targeted protein of ferredoxin-thioredoxin reductase catalytic chain of Spinacia oleracea with UniProtKB Id-P41348 exhibits properties of cellular internalization. DNase I was efficiently delivered into the chloroplast using 10 μM cTP with an efficiency of more than 90%. This cell-penetrating peptide-mediated approach offers various advantages over the existing chloroplast targeting methods, such as non-invasiveness, biocompatibility, low-toxicity, and target-specific delivery. The present study shows that peptide-based strategies hold tremendous potential in the field of chloroplast biotechnology. KEY POINTS: • Screening of database of chloroplast targeting peptides in order to develop an efficient cell-penetrating peptide termed as cTP. • cTP efficiently crosses the cell barrier and demonstrated chloroplast-localization. • cTP can be incorporated as a promising strategy for delivering macromolecules for crop improvement.
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7
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Modeling Adsorption, Conformation, and Orientation of the Fis1 Tail Anchor at the Mitochondrial Outer Membrane. MEMBRANES 2022; 12:membranes12080752. [PMID: 36005667 PMCID: PMC9413518 DOI: 10.3390/membranes12080752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/28/2022] [Accepted: 07/28/2022] [Indexed: 12/04/2022]
Abstract
Proteins can be targeted to organellar membranes by using a tail anchor (TA), a stretch of hydrophobic amino acids found at the polypeptide carboxyl-terminus. The Fis1 protein (Fis1p), which promotes mitochondrial and peroxisomal division in the yeast Saccharomyces cerevisiae, is targeted to those organelles by its TA. Substantial evidence suggests that Fis1p insertion into the mitochondrial outer membrane can occur without the need for a translocation machinery. However, recent findings raise the possibility that Fis1p insertion into mitochondria might be promoted by a proteinaceous complex. Here, we have performed atomistic and coarse-grained molecular dynamics simulations to analyze the adsorption, conformation, and orientation of the Fis1(TA). Our results support stable insertion at the mitochondrial outer membrane in a monotopic, rather than a bitopic (transmembrane), configuration. Once inserted in the monotopic orientation, unassisted transition to the bitopic orientation is expected to be blocked by the highly charged nature of the TA carboxyl-terminus and by the Fis1p cytosolic domain. Our results are consistent with a model in which Fis1p does not require a translocation machinery for insertion at mitochondria.
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8
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Pal T, Paul R, Paul S. Phenylpropanoids on the Inhibition of β-Amyloid Aggregation and the Movement of These Molecules through the POPC Lipid Bilayer. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:7775-7790. [PMID: 35687701 DOI: 10.1021/acs.langmuir.2c00827] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Alzheimer's disease (AD), caused by Aβ aggregation, is a major concern in medical research. It is a neurodegenerative disorder, leading to a loss of cognitive abilities, which is still claiming the lives of many people all over the world. This poses a challenge before the scientific community to discover effective drugs which can prevent such toxic aggregation. Recent experimental findings suggest the potency of two naturally-occurring phenylpropanoids, Schizotenuin A (SCH) and Lycopic Acid B (LAB) which can effectively combat the deleterious effects of Aβ aggregation, although nothing is known about their mechanism of inhibition. In this work, we deal with an extensive computational study on the inhibitory effects of these inhibitors by using an all-atom molecular dynamics simulation to interpret the underlying mechanism of their inhibitory processes. A series of investigations is carried out while studying the various structural and conformational changes of the peptide chains in the absence and presence of inhibitors. To investigate the details of the interactions between the peptide residues and inhibitors, nonbonding energy calculations, the radial distribution function, the coordination number of water and inhibitor molecules around the peptide residues, and hydrogen-bonding interactions are calculated. The potential of mean force (PMF) is calculated to estimate aggregate formation from their free-energy profiles. It is seen that the hydrophobic core of the KLVFFAE undergoes aggregation and that these inhibitors show great promise in preventing the onset of AD in the future by preventing Aβ aggregation. Also, the translocation studies on these inhibitors through a model POPC lipid bilayer shed light on their permeation properties and biocompatibility.
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Affiliation(s)
- Triasha Pal
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam, India 781039
| | - Rabindranath Paul
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam, India 781039
| | - Sandip Paul
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam, India 781039
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9
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Kang Z, Liu Q, Zhang Z, Zheng Y, Wang C, Pan Z, Li Q, Liu Y, Shi L. Arginine-Rich Polymers with Pore-Forming Capability Enable Efficient Intracellular Delivery via Direct Translocation Across Cell Membrane. Adv Healthc Mater 2022; 11:e2200371. [PMID: 35460333 DOI: 10.1002/adhm.202200371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 04/06/2022] [Indexed: 11/07/2022]
Abstract
Efficient delivery of biomacromolecules or drugs across the cell membrane via endocytosis usually encounters inevitable entrapment in endosomes and subsequent degradation in lyso-endosomes. To address this issue, a series of arginine-rich cell penetrating polymers is designed and synthesized, which internalize into cells by inducing the formation of pores on the cell membrane, thereby crossing the cell membrane via direct translocation that fundamentally avoids endo/lysosomal entrapment. The structure-activity relationship studies show that PTn-R2-C6, which is a type of polymer that has two arginine residues and a flexible hexanoic acid linker in each side chain, exhibits excellent pore-formation ability on the cell membrane. Further investigations indicate that PTn-R2-C6 rapidly transports plasmid DNAs into cytosol through a similar endocytosis-independent pathway, thereby achieving significantly higher transfection efficiency and lower cytotoxicity than the gold-standard transfection reagent PEI 25K. These results suggest the great potential of PTn-R2-C6 as a safe and efficient gene transfection reagent for wide applications including disease treatments, vaccine development, and biomedical research purposes.
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Affiliation(s)
- Ziyao Kang
- State Key Laboratory of Medicinal Chemical Biology Key Laboratory of Functional Polymer Materials of Ministry of Education College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Tianjin 300071 P. R. China
| | - Qi Liu
- State Key Laboratory of Medicinal Chemical Biology Key Laboratory of Functional Polymer Materials of Ministry of Education College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Tianjin 300071 P. R. China
| | - Zhanzhan Zhang
- State Key Laboratory of Medicinal Chemical Biology Key Laboratory of Functional Polymer Materials of Ministry of Education College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Tianjin 300071 P. R. China
| | - Yadan Zheng
- State Key Laboratory of Medicinal Chemical Biology Key Laboratory of Functional Polymer Materials of Ministry of Education College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Tianjin 300071 P. R. China
| | - Chun Wang
- State Key Laboratory of Medicinal Chemical Biology Key Laboratory of Functional Polymer Materials of Ministry of Education College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Tianjin 300071 P. R. China
| | - Zheng Pan
- State Key Laboratory of Medicinal Chemical Biology Key Laboratory of Functional Polymer Materials of Ministry of Education College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Tianjin 300071 P. R. China
| | - Qiushi Li
- State Key Laboratory of Medicinal Chemical Biology Key Laboratory of Functional Polymer Materials of Ministry of Education College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Tianjin 300071 P. R. China
| | - Yang Liu
- State Key Laboratory of Medicinal Chemical Biology Key Laboratory of Functional Polymer Materials of Ministry of Education College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Tianjin 300071 P. R. China
| | - Linqi Shi
- State Key Laboratory of Medicinal Chemical Biology Key Laboratory of Functional Polymer Materials of Ministry of Education College of Chemistry Frontiers Science Center for New Organic Matter Nankai University Tianjin 300071 P. R. China
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10
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Cardenas AE, Drexler CI, Nechushtai R, Mittler R, Friedler A, Webb LJ, Elber R. Peptide Permeation across a Phosphocholine Membrane: An Atomically Detailed Mechanism Determined through Simulations and Supported by Experimentation. J Phys Chem B 2022; 126:2834-2849. [PMID: 35388695 PMCID: PMC9074375 DOI: 10.1021/acs.jpcb.1c10966] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cell-penetrating peptides (CPPs) facilitate translocation across biological membranes and are of significant biological and medical interest. Several CPPs can permeate into specific cells and organelles. We examine the incorporation and translocation of a novel anticancer CPP in a dioleoylphosphatidylcholine (DOPC) lipid bilayer membrane. The peptide, NAF-144-67, is a short fragment of a transmembrane protein, consisting of hydrophobic N-terminal and charged C-terminal segments. Experiments using fluorescently labeled NAF-144-67 in ∼100 nm DOPC vesicles and atomically detailed simulations conducted with Milestoning support a model in which a significant barrier for peptide-membrane entry is found at the interface between the aqueous solution and membrane. The initial step is the insertion of the N-terminal segment and the hydrophobic helix into the membrane, passing the hydrophilic head groups. Both experiments and simulations suggest that the free energy difference in the first step of the permeation mechanism in which the hydrophobic helix crosses the phospholipid head groups is -0.4 kcal mol-1 slightly favoring motion into the membrane. Milestoning calculations of the mean first passage time and the committor function underscore the existence of an early polar barrier followed by a diffusive barrierless motion in the lipid tail region. Permeation events are coupled to membrane fluctuations that are examined in detail. Our study opens the way to investigate in atomistic resolution the molecular mechanism, kinetics, and thermodynamics of CPP permeation to diverse membranes.
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Affiliation(s)
- Alfredo E Cardenas
- Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Chad I Drexler
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Rachel Nechushtai
- The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat-Ram, Jerusalem 91904, Israel
| | - Ron Mittler
- The Department of Surgery, University of Missouri School of Medicine, Christopher S. Bond Life Sciences Center, University of Missouri, 1201 Rollins Street, Columbia, Missouri 65201, United States
| | - Assaf Friedler
- The Institute of Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat-Ram, Jerusalem 91904, Israel
| | - Lauren J Webb
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Ron Elber
- Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, Texas 78712, United States.,Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
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11
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Paul R, Bera S, Devi M, Paul S. Inhibition of Aβ 16–22 Peptide Aggregation by Small Molecules and Their Permeation through POPC Lipid Bilayer: Insight from Molecular Dynamics Simulation Study. J Chem Inf Model 2022; 62:5193-5207. [DOI: 10.1021/acs.jcim.1c01366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Rabindranath Paul
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam, India 781039
| | - Siddhartha Bera
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam, India 781039
| | - Madhusmita Devi
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam, India 781039
| | - Sandip Paul
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam, India 781039
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12
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Negi S, Hamori M, Kawahara-Nakagawa Y, Imanishi M, Kurehara M, Kitada C, Kawahito Y, Kishi K, Manabe T, Kawamura N, Kitagishi H, Mashimo M, Shibata N, Sugiura Y. Importance of two-dimensional cation clusters induced by protein folding in intrinsic intracellular membrane permeability. RSC Chem Biol 2022; 3:1076-1084. [PMID: 35975000 PMCID: PMC9347356 DOI: 10.1039/d2cb00098a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 07/11/2022] [Indexed: 11/21/2022] Open
Abstract
Two-dimensional cation clusters formed on the surface of proteins play an important role in their intracellular translocation.
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Affiliation(s)
- Shigeru Negi
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto 610-0395, Japan
| | - Mami Hamori
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto 610-0395, Japan
| | - Yuka Kawahara-Nakagawa
- Graduate School of Life Science, University of Hyogo, 3-2-1 Kouto, Kamigori-cho, Ako-gun, Hyogo, 678-1297, Japan
| | - Miki Imanishi
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Miku Kurehara
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto 610-0395, Japan
| | - Chieri Kitada
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto 610-0395, Japan
| | - Yuri Kawahito
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto 610-0395, Japan
| | - Kanae Kishi
- Graduate School of Biomedical and Health Sciences, Hiroshima University, 1-2-3 Kasumi Minami-ku, Hiroshima, 734-8553, Japan
| | - Takayuki Manabe
- Clinical Research Support Center, Asahikawa Medical University Hospital, 2-1-1-1 Midorigaokahigashi, Asahikawa 078-8510, Japan
| | - Nobuyuki Kawamura
- Education Center for Pharmacy, Faculty of Pharmaceutical Sciences, Niigata University of Pharmacy and Applied Life Sciences, 265-1 Higashijima, Akiha-ku, Niigata City, Niigata 956-8603, Japan
| | - Hiroaki Kitagishi
- Department of Molecular Chemistry and Biochemistry, Faculty of Science and Engineering, Doshisha University, Kyotanabe, Kyoto 610-0321, Japan
| | - Masato Mashimo
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto 610-0395, Japan
| | - Nobuhito Shibata
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto 610-0395, Japan
| | - Yukio Sugiura
- Faculty of Pharmaceutical Science, Doshisha Women's University, Koudo, Kyotanabe, Kyoto 610-0395, Japan
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13
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Le HH, Cinaroglu SS, Manalo EC, Ors A, Gomes MM, Duan Sahbaz B, Bonic K, Origel Marmolejo CA, Quentel A, Plaut JS, Kawashima TE, Ozdemir ES, Malhotra SV, Ahiska Y, Sezerman U, Bayram Akcapinar G, Saldivar JC, Timucin E, Fischer JM. Molecular modelling of the FOXO4-TP53 interaction to design senolytic peptides for the elimination of senescent cancer cells. EBioMedicine 2021; 73:103646. [PMID: 34689087 PMCID: PMC8546421 DOI: 10.1016/j.ebiom.2021.103646] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 10/07/2021] [Accepted: 10/08/2021] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Senescent cells accumulate in tissues over time as part of the natural ageing process and the removal of senescent cells has shown promise for alleviating many different age-related diseases in mice. Cancer is an age-associated disease and there are numerous mechanisms driving cellular senescence in cancer that can be detrimental to recovery. Thus, it would be beneficial to develop a senolytic that acts not only on ageing cells but also senescent cancer cells to prevent cancer recurrence or progression. METHODS We used molecular modelling to develop a series of rationally designed peptides to mimic and target FOXO4 disrupting the FOXO4-TP53 interaction and releasing TP53 to induce apoptosis. We then tested these peptides as senolytic agents for the elimination of senescent cells both in cell culture and in vivo. FINDINGS Here we show that these peptides can act as senolytics for eliminating senescent human cancer cells both in cell culture and in orthotopic mouse models. We then further characterized one peptide, ES2, showing that it disrupts FOXO4-TP53 foci, activates TP53 mediated apoptosis and preferentially binds FOXO4 compared to TP53. Next, we show that intratumoural delivery of ES2 plus a BRAF inhibitor results in a significant increase in apoptosis and a survival advantage in mouse models of melanoma. Finally, we show that repeated systemic delivery of ES2 to older mice results in reduced senescent cell numbers in the liver with minimal toxicity. INTERPRETATION Taken together, our results reveal that peptides can be generated to specifically target and eliminate FOXO4+ senescent cancer cells, which has implications for eradicating residual disease and as a combination therapy for frontline treatment of cancer. FUNDING This work was supported by the Cancer Early Detection Advanced Research Center at Oregon Health & Science University.
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Affiliation(s)
- Hillary H Le
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health & Science University, USA
| | - Suleyman S Cinaroglu
- Institute of Health Sciences, Acibadem Mehmet Ali Aydinlar University, Atasehir Istanbul 34752, Turkey; Eternans Ltd., UK
| | - Elise C Manalo
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health & Science University, USA
| | - Aysegul Ors
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health & Science University, USA
| | - Michelle M Gomes
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health & Science University, USA
| | | | - Karla Bonic
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health & Science University, USA
| | - Carlos A Origel Marmolejo
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health & Science University, USA
| | - Arnaud Quentel
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health & Science University, USA
| | - Justin S Plaut
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health & Science University, USA; Dept of Bioengineering, University of California San Diego, USA
| | - Taryn E Kawashima
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health & Science University, USA
| | - E Sila Ozdemir
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health & Science University, USA
| | - Sanjay V Malhotra
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health & Science University, USA; Dept of Cell, Developmental and Cancer Biology, Oregon Health & Science University, USA
| | | | - Ugur Sezerman
- Eternans Ltd., UK; School of Medicine, Acibadem Mehmet Ali Aydinlar University, Atasehir Istanbul 34752, Turkey
| | - Gunseli Bayram Akcapinar
- Institute of Health Sciences, Acibadem Mehmet Ali Aydinlar University, Atasehir Istanbul 34752, Turkey; Eternans Ltd., UK
| | - Joshua C Saldivar
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health & Science University, USA; Division of Oncological Sciences, Knight Cancer Institute, Oregon Health & Science University, USA
| | - Emel Timucin
- Eternans Ltd., UK; School of Medicine, Acibadem Mehmet Ali Aydinlar University, Atasehir Istanbul 34752, Turkey
| | - Jared M Fischer
- Cancer Early Detection Advanced Research Center, Knight Cancer Institute, Oregon Health & Science University, USA; Dept of Molecular and Medical Genetics, Oregon Health & Science University, USA.
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14
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Herrera R, Rosbe K, Tugizov SM. Inactivation of HIV-1 in Polarized Infant Tonsil Epithelial Cells by Human Beta-Defensins 2 and 3 Tagged with the Protein Transduction Domain of HIV-1 Tat. Viruses 2021; 13:v13102043. [PMID: 34696473 PMCID: PMC8538026 DOI: 10.3390/v13102043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/04/2021] [Accepted: 10/06/2021] [Indexed: 11/16/2022] Open
Abstract
Mother-to-child transmission (MTCT) of HIV-1 may occur during pregnancy, labor, and breastfeeding; however, the molecular mechanism of MTCT of virus remains poorly understood. Infant tonsil mucosal epithelium may sequester HIV-1, serving as a transient reservoir, and may play a critical role in MTCT. Innate immune proteins human beta-defensins 2 (hBD-2) and -3 may inactivate intravesicular virions. To establish delivery of hBD-2 and -3 into vesicles containing HIV-1, we tagged hBDs with the protein transduction domain (PTD) of HIV-1 Tat, which facilitates an efficient translocation of proteins across cell membranes. Our new findings showed that hBD-2 and -3 proteins tagged with PTD efficiently penetrated polarized tonsil epithelial cells by endocytosis and direct penetration. PTD-initiated internalization of hBD-2 and -3 proteins into epithelial cells led to their subsequent penetration of multivesicular bodies (MVB) and vacuoles containing HIV-1. Furthermore, PTD played a role in the fusion of vesicles containing HIV-1 with lysosomes, where virus was inactivated. PTD-initiated internalization of hBD-2 and -3 proteins into ex vivo tonsil tissue explants reduced the spread of virus from epithelial cells to CD4+ T lymphocytes, CD68+ macrophages, and CD1c+ dendritic cells, suggesting that this approach may serve as an antiviral strategy for inactivating intraepithelial HIV-1 and reducing viral MTCT.
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Affiliation(s)
- Rossana Herrera
- Department of Medicine, University of California–San Francisco, 513 Parnassus Ave., San Francisco, CA 94143, USA;
| | - Kristina Rosbe
- Department of Otolaryngology, University of California–San Francisco, San Francisco, CA 94115, USA;
| | - Sharof M. Tugizov
- Department of Medicine, University of California–San Francisco, 513 Parnassus Ave., San Francisco, CA 94143, USA;
- Correspondence: ; Tel.: +1-(415)-514-3177; Fax: +1-(415)-476-9364
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15
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Paul R, Paul S. Translocation of Endo-Functionalized Molecular Tubes across Different Lipid Bilayers: Atomistic Molecular Dynamics Simulation Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:10376-10387. [PMID: 34415773 DOI: 10.1021/acs.langmuir.1c01594] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Various artificial receptors, such as calixarenes, cyclodextrins, cucurbit[n]urils, and their acyclic compounds, pliiar[n]arenes, deep cavitands, and molecular tweezers, can permeate the lipid membranes and they are used as drug carriers to improve the drug solubility, stability, and bioavailability. Inspired by these, we have employed atomistic molecular dynamics simulation to examine the effects of endo-functionalized molecular tubes or naphthotubes (host-1a and host-1b) on seven different types of model lipid bilayers and the permeation properties of these receptors through these model lipid bilayers. Lipid types include six model lipid bilayers (POPC, POPE, DOPC, POPG, DPPE, POPE/POPG) and one realistic membrane (Yeast). We observe that these receptors are spontaneously translocated toward these model lipid bilayer head regions and do not proceed further into these lipid bilayer tail regions (reside at the interface between lipid head and lipid tail region), except for the DPPE-containing systems. In the DPPE model lipid bilayer-containing systems (1a-dppe and 1b-dppe), receptor molecules are only adsorbed on the bilayer surface and reside at the interface between lipid head and water. This finding is also supported by the biased free-energy profiles of these translocation processes. Passive transport of these receptors may be possible through these model lipid bilayers (due to low barrier height), except for DPPE bilayer-containing systems (that have a very high energy barrier at the center). The results from these simulations provide insight into the biocompatibility of host-1a or host-1b in microscopic detail. Based on this work, more research is needed to fully comprehend the role of these synthesized receptors as a prospective drug carrier.
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Affiliation(s)
- Rabindranath Paul
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam 781039, India
| | - Sandip Paul
- Department of Chemistry, Indian Institute of Technology, Guwahati, Assam 781039, India
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16
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Chen P, Vorobyov I, Roux B, Allen TW. Molecular Dynamics Simulations Based on Polarizable Models Show that Ion Permeation Interconverts between Different Mechanisms as a Function of Membrane Thickness. J Phys Chem B 2021; 125:1020-1035. [PMID: 33493394 DOI: 10.1021/acs.jpcb.0c08613] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Different mechanisms have been proposed to explain the permeation of charged compounds through lipid membranes. Overall, it is expected that an ion-induced defect permeation mechanism, where substantial membrane deformations accompany ion movement, should be dominant in thin membranes but that a solubility-diffusion mechanism, where ions partition into the membrane core with large associated dehydration energy costs, becomes dominant in thicker membranes. However, while this physical picture is intuitively reasonable, capturing the interconversion between these two permeation mechanisms in molecular dynamics (MD) simulations based on atomic models is challenging. In particular, simulations relying on nonpolarizable force fields are artificially unfavorable to the solubility-diffusion mechanism, as induced polarization of the nonpolar hydrocarbon is ignored, causing overestimated free energy costs for charged molecules to enter into this region of the membrane. In this study, all-atom MD simulations based on nonpolarizable and polarizable force fields are used to quantitatively characterize the permeation process for the arginine side chain analog methyl-guanidinium through bilayer membranes of mono-unsaturated phosphatidylcholine lipids with and without cholesterol, resulting in thicknesses spanning from ∼24 to ∼42 Å. With simulations based on a nonpolarizable force field, ion translocation can take place solely through an ion-induced defect mechanism, with free energy barriers increasing linearly from 14 to 40 kcal/mol, depending on the thickness. However, with simulations based on a polarizable force field, ion translocation is predominantly dominated by an ion-induced defect mechanism in thin membranes, which progressively converts to a solubility-diffusion mechanism as the membranes get thicker. The transition between the two mechanisms occurs at a thickness of ∼29 Å, with lipid tails of 22 or more carbon atoms. This situation appears to represent the upper limit for ion-induced defect permeation within the current polarizable models. Beyond this thickness, it becomes energetically preferable for the ion to dehydrate and partition into the membrane core-a phenomenon that cannot be captured using the nonpolarizable models. Induced electronic polarizability therefore leads not just to a shift in permeation energetics but to an interconversion between two strikingly different physical mechanisms. The result highlights the importance of induced polarizability in modeling lipid membranes.
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Affiliation(s)
- Peiran Chen
- Department of Chemistry, University of California, Davis, California 95616, United States
| | - Igor Vorobyov
- Department of Physiology & Membrane Biology, Department of Pharmacology, University of California, Davis, California 95616, United States
| | - Benoît Roux
- Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States
| | - Toby W Allen
- School of Science, RMIT University, Melbourne 3001, Australia
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17
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Young CC, Vedadghavami A, Bajpayee AG. Bioelectricity for Drug Delivery: The Promise of Cationic Therapeutics. Bioelectricity 2020; 2:68-81. [PMID: 32803148 DOI: 10.1089/bioe.2020.0012] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Biological systems overwhelmingly comprise charged entities generating electrical activity that can have significant impact on biological structure and function. This intrinsic bio-electrical activity can also be harnessed for overcoming the tissue matrix and cell membrane barriers, which have been outstanding challenges for targeted drug delivery, by using rationally designed cationic carriers. The weak and reversible long-range electrostatic interactions with fixed negatively charged groups facilitate electro-diffusive transport of cationic therapeutics through full-tissue thickness to effectively reach intra-tissue, cellular, and intracellular target sites. This article presents a perspective on the promise of using rationally designed cationic biomaterials in targeted drug delivery, the underlying charge-based mechanisms, and bio-transport phenomena while addressing outstanding concerns around toxicity and methods to mitigate them. We also discuss electrically charged drugs that are currently being evaluated in clinical trials and identify areas of further development that have the potential to usher in new treatments.
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Affiliation(s)
- Cameron C Young
- Department of Chemical Engineering, Northeastern University, Boston, Massachusetts, USA
| | - Armin Vedadghavami
- Department of Bioengineering, Northeastern University, Boston, Massachusetts, USA
| | - Ambika G Bajpayee
- Department of Bioengineering, Northeastern University, Boston, Massachusetts, USA.,Department of Mechanical and Industrial Engineering, Northeastern University, Boston, Massachusetts, USA
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18
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Lee MW, de Anda J, Kroll C, Bieniossek C, Bradley K, Amrein KE, Wong GCL. How do cyclic antibiotics with activity against Gram-negative bacteria permeate membranes? A machine learning informed experimental study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183302. [PMID: 32311341 DOI: 10.1016/j.bbamem.2020.183302] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 03/26/2020] [Accepted: 03/30/2020] [Indexed: 12/30/2022]
Abstract
All antibiotics have to engage bacterial amphiphilic barriers such as the lipopolysaccharide-rich outer membrane or the phospholipid-based inner membrane in some manner, either by disrupting them outright and/or permeating them and thereby allow the antibiotic to get into bacteria. There is a growing class of cyclic antibiotics, many of which are of bacterial origin, that exhibit activity against Gram-negative bacteria, which constitute an urgent problem in human health. We examine a diverse collection of these cyclic antibiotics, both natural and synthetic, which include bactenecin, polymyxin B, octapeptin, capreomycin, and Kirshenbaum peptoids, in order to identify what they have in common when they interact with bacterial lipid membranes. We find that they virtually all have the ability to induce negative Gaussian curvature (NGC) in bacterial membranes, the type of curvature geometrically required for permeation mechanisms such as pore formation, blebbing, and budding. This is interesting since permeation of membranes is a function usually ascribed to antimicrobial peptides (AMPs) from innate immunity. As prototypical test cases of cyclic antibiotics, we analyzed amino acid sequences of bactenecin, polymyxin B, and capreomycin using our recently developed machine-learning classifier trained on α-helical AMP sequences. Although the original classifier was not trained on cyclic antibiotics, a modified classifier approach correctly predicted that bactenecin and polymyxin B have the ability to induce NGC in membranes, while capreomycin does not. Moreover, the classifier was able to recapitulate empirical structure-activity relationships from alanine scans in polymyxin B surprisingly well. These results suggest that there exists some common ground in the sequence design of hybrid cyclic antibiotics and linear AMPs.
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Affiliation(s)
- Michelle W Lee
- Department of Bioengineering, Department of Chemistry, California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, United States
| | - Jaime de Anda
- Department of Bioengineering, Department of Chemistry, California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, United States
| | - Carsten Kroll
- Roche Pharma Research and Early Development Pharmaceutical Science, Roche, Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
| | - Christoph Bieniossek
- Roche Pharma Research and Early Development Pharmaceutical Science, Roche, Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
| | - Kenneth Bradley
- Roche Pharma Research and Early Development Pharmaceutical Science, Roche, Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
| | - Kurt E Amrein
- Roche Pharma Research and Early Development Pharmaceutical Science, Roche, Innovation Center Basel, F. Hoffmann-La Roche Ltd, 4070 Basel, Switzerland
| | - Gerard C L Wong
- Department of Bioengineering, Department of Chemistry, California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, United States.
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19
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Wong CY, Al-Salami H, Dass CR. Cellular assays and applied technologies for characterisation of orally administered protein nanoparticles: a systematic review. J Drug Target 2020; 28:585-599. [DOI: 10.1080/1061186x.2020.1726356] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Chun Y. Wong
- School of Pharmacy and Biomedical Science, Curtin University, Bentley, Australia
- Curtin Health Innovation Research Institute, Bentley, Australia
| | - Hani. Al-Salami
- School of Pharmacy and Biomedical Science, Curtin University, Bentley, Australia
- Curtin Health Innovation Research Institute, Bentley, Australia
- Biotechnology and Drug Development Research Laboratory, Curtin University, Bentley, Australia
| | - Crispin R. Dass
- School of Pharmacy and Biomedical Science, Curtin University, Bentley, Australia
- Curtin Health Innovation Research Institute, Bentley, Australia
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20
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Pilkington AW, Schupp J, Nyman M, Valentine SJ, Smith DM, Legleiter J. Acetylation of Aβ 40 Alters Aggregation in the Presence and Absence of Lipid Membranes. ACS Chem Neurosci 2020; 11:146-161. [PMID: 31834770 DOI: 10.1021/acschemneuro.9b00483] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
A hallmark of Alzheimer's disease (AD) is the formation of senile plaques comprised of the β-amyloid (Aβ) peptide. Aβ fibrillization is a complex nucleation-dependent process involving a variety of metastable intermediate aggregates and features the formation of inter- and intramolecular salt bridges involving lysine residues, K16 and K28. Cationic lysine residues also mediate protein-lipid interactions via association with anionic lipid headgroups. As several toxic mechanisms attributed to Aβ involve membrane interactions, the impact of acetylation on Aβ40 aggregation in the presence and absence of membranes was determined. Using chemical acetylation, varying mixtures of acetylated and nonacetylated Aβ40 were produced. With increasing acetylation, fibril and oligomer formation decreased, eventually completely arresting fibrillization. In the presence of total brain lipid extract (TBLE) vesicles, acetylation reduced the interaction of Aβ40 with membranes; however, fibrils still formed at near complete levels of acetylation. Additionally, the combination of TBLE and acetylated Aβ promoted annular aggregates. Finally, toxicity associated with Aβ40 was reduced with increasing acetylation in a cell culture assay. These results suggest that in the absence of membranes that the cationic character of lysine plays a major role in fibril formation. However, acetylation promotes unique aggregation pathways in the presence of lipid membranes.
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Affiliation(s)
- Albert W. Pilkington
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Jane Schupp
- Department of Biochemistry, West Virginia University, Morgantown, West Virginia 26506, United States
| | - Morgan Nyman
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - Stephen J. Valentine
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
| | - David M. Smith
- Department of Biochemistry, West Virginia University, Morgantown, West Virginia 26506, United States
- Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Drive, P.O. Box 9303, Morgantown, West Virginia 26505, United States
- Department of Neuroscience, West Virginia University, 1 Medical Center Drive, P.O. Box
9303, Morgantown, West Virginia 26505, United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry, West Virginia University, 217 Clark Hall, Morgantown, West Virginia 26506, United States
- Rockefeller Neurosciences Institutes, West Virginia University, 1 Medical Center Drive, P.O. Box 9303, Morgantown, West Virginia 26505, United States
- Department of Neuroscience, West Virginia University, 1 Medical Center Drive, P.O. Box
9303, Morgantown, West Virginia 26505, United States
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21
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Reid LM, Verma CS, Essex JW. The role of molecular simulations in understanding the mechanisms of cell-penetrating peptides. Drug Discov Today 2019; 24:1821-1835. [DOI: 10.1016/j.drudis.2019.06.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 05/12/2019] [Accepted: 06/17/2019] [Indexed: 01/06/2023]
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22
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Pilkington AW, Donohoe GC, Akhmedov NG, Ferrebee T, Valentine SJ, Legleiter J. Hydrogen Peroxide Modifies Aβ-Membrane Interactions with Implications for Aβ 40 Aggregation. Biochemistry 2019; 58:2893-2905. [PMID: 31187978 DOI: 10.1021/acs.biochem.9b00233] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Alzheimer's disease (AD) is pathologically characterized by the formation of extracellular senile plaques, predominately comprised of aggregated β-amyloid (Aβ), deposited in the brain. Aβ aggregation can result in a myriad of distinct aggregate species, from soluble oligomers to insoluble fibrils. Aβ strongly interacts with membranes, which can be linked to a variety of potential toxic mechanisms associated with AD. Oxidative damage accompanies the formation of Aβ aggregates, with a 10-50% proportion of Aβ aggregates being oxidized in vivo. Hydrogen peroxide (H2O2) is a reactive oxygen species implicated in a number of neurodegenerative diseases. Recent evidence has demonstrated that the H2O2 concentration fluctuates rapidly in the brain, resulting in large concentration spikes, especially in the synaptic cleft. Here, the impact of environmental H2O2 on Aβ aggregation in the presence and absence of lipid membranes is investigated. Aβ40 was exposed to H2O2, resulting in the selective oxidation of methionine 35 (Met35) to produce Aβ40Met35[O]. While oxidation mildly reduced the rate of Aβ aggregation and produced a distinct fibril morphology at high H2O2 concentrations, H2O2 had a much more pronounced impact on Aβ aggregation in the presence of total brain lipid extract vesicles. The impact of H2O2 on Aβ aggregation in the presence of lipids was associated with a reduced affinity of Aβ for the vesicle surface. However, this reduced vesicle affinity was predominately associated with lipid peroxidation rather than Aβ oxidation.
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Affiliation(s)
- Albert W Pilkington
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Gregory C Donohoe
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Novruz G Akhmedov
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Timothy Ferrebee
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Stephen J Valentine
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States
| | - Justin Legleiter
- The C. Eugene Bennett Department of Chemistry , West Virginia University , 217 Clark Hall , Morgantown , West Virginia 26506 , United States.,Blanchette Rockefeller Neurosciences Institutes , West Virginia University , 1 Medical Center Drive , P.O. Box 9303, Morgantown , West Virginia 26505 , United States.,Department of Neuroscience , West Virginia University , 1 Medical Center Drive , P.O. Box 9303, Morgantown , West Virginia 26505 , United States
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23
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Liang J, Wang H, Libera M. Biomaterial surfaces self-defensive against bacteria by contact transfer of antimicrobials. Biomaterials 2019; 204:25-35. [PMID: 30875516 PMCID: PMC10755758 DOI: 10.1016/j.biomaterials.2019.03.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 03/04/2019] [Accepted: 03/07/2019] [Indexed: 11/17/2022]
Abstract
Despite extensive engineering of tissue-contacting biomedical devices to control healing, these devices remain susceptible to bacterial colonization, biofilm formation, and chronic infection. The threat of selecting for resistance genes largely precludes sustained antimicrobial elution as a wide-spread clinical solution. In response, self-defensive surfaces have been developed where antimicrobial is released only when and where there is a bacterial challenge. We explore a new self-defensive approach using anionic microgels into which small-molecule cationic antimicrobials are loaded by complexation. We identify conditions where antimicrobial remains sequestered within the microgels for periods as long as weeks. However, bacterial contact triggers release and leads to local bacterial killing. We speculate that the close proximity of bacteria alters the local thermodynamic environment and interferes with the microgel-antimicrobial complexation. The contact-transfer approach does not require bacterial metabolism but instead appears to be driven by differences between the microgels and the bacterial cell envelope where there is a high concentration of negative charge and hydrophobicity. Contact with metabolizing macrophages or osteoblasts is, however, insufficient to trigger antimicrobial release, indicating that contact transfer can be specific to bacteria and suggesting an avenue to biomedical device surfaces that can simultaneously promote healing and resist infection.
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Affiliation(s)
- Jing Liang
- Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey, 07030, USA
| | - Hongjun Wang
- Department of Biomedical Engineering, Stevens Institute of Technology, Hoboken, NJ, 07030, USA
| | - Matthew Libera
- Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Hoboken, New Jersey, 07030, USA.
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24
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Ramírez PG, Del Pópolo MG, Vila JA, Szleifer I, Longo GS. Adsorption and insertion of polyarginine peptides into membrane pores: The trade-off between electrostatics, acid-base chemistry and pore formation energy. J Colloid Interface Sci 2019; 552:701-711. [PMID: 31176053 DOI: 10.1016/j.jcis.2019.05.087] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 05/24/2019] [Accepted: 05/25/2019] [Indexed: 12/21/2022]
Abstract
The mechanism that arginine-rich cell penetrating peptides (ARCPPs) use to translocate lipid membranes is not entirely understood. In the present work, we develop a molecular theory that allows to investigate the adsorption and insertion of ARCPPs on membranes bearing hydrophilic pores. This method accounts for size, shape, conformation, protonation state and charge distribution of the peptides; it also describes the state of protonation of acidic membrane lipids. We present a systematic investigation of the effect of pore size, peptide concentration and sequence length on the extent of peptide adsorption and insertion into the pores. We show that adsorption on the intact (non-porated) lipid membrane plays a key role on peptide translocation. For peptides shorter than nona-arginine, adsorption on the intact membrane increases significantly with chain length, but it saturates for longer peptides. However, this adsorption behavior only occurs at relatively low peptide concentrations; increasing peptide concentration favors adsorption of the shorter molecules. Adsorption of longer peptides increases the intact membrane negative charge as a result of further deprotonation of acidic lipids. Peptide insertion into the pores depends non-monotonically on pore radius, which reflects the short range nature of the effective membrane-peptide interactions. The size of the pore that promotes maximum adsorption depends on the peptide chain length. Peptide translocation is a thermally activated process, so we complement our thermodynamic approach with a simple kinetic model that allows to rationalize the ARCPPs translocation rate in terms of the free energy gain of adsorption, and the energy cost of creating a transmembrane pore with peptides in it. Our results indicate that strategies to improve translocation efficiency should focus on enhancing peptide adsorption.
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Affiliation(s)
- Pedro G Ramírez
- Instituto de Matemática Aplicada San Luis (IMASL), UNSL-CONICET, San Luis, Argentina
| | - Mario G Del Pópolo
- IICB-CONICET & Facultad de Ciencias Exactas y Naturales (FCEN), UNCuyo, Mendoza, Argentina
| | - Jorge A Vila
- Instituto de Matemática Aplicada San Luis (IMASL), UNSL-CONICET, San Luis, Argentina
| | - I Szleifer
- Department of Biomedical Engineering, Department of Chemistry and Chemistry of Life Processes Institute, Northwestern University, Evanston IL, USA
| | - Gabriel S Longo
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), UNLP-CONICET, La Plata, Argentina.
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25
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Ohgita T, Takechi-Haraya Y, Nadai R, Kotani M, Tamura Y, Nishikiori K, Nishitsuji K, Uchimura K, Hasegawa K, Sakai-Kato K, Akaji K, Saito H. A novel amphipathic cell-penetrating peptide based on the N-terminal glycosaminoglycan binding region of human apolipoprotein E. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:541-549. [DOI: 10.1016/j.bbamem.2018.12.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 11/17/2018] [Accepted: 12/13/2018] [Indexed: 11/15/2022]
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26
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Cellular internalization of a cell-penetrating peptide conjugated gastrin-releasing peptide receptor antagonist. J Radioanal Nucl Chem 2019. [DOI: 10.1007/s10967-019-06418-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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27
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Anderson CM, Cardenas A, Elber R, Webb LJ. Preferential Equilibrium Partitioning of Positively Charged Tryptophan into Phosphatidylcholine Bilayer Membranes. J Phys Chem B 2018; 123:170-179. [PMID: 30481465 PMCID: PMC6331081 DOI: 10.1021/acs.jpcb.8b09872] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
The interactions between small molecules
and lipid bilayers play
a critical role in the function of cellular membranes. Understanding
how a small molecule interacts with the lipid bilayer differently
based on its charge reveals primordial mechanisms of transport across
membranes and assists in the design of drug molecules that can penetrate
cells. We have previously reported that tryptophan permeated through
a phosphatidylcholine lipid bilayer membrane at a faster rate when
it was positively charged (Trp+) than when negatively charged (Trp−),
which corresponded to a lower potential of mean force (PMF) barrier
determined through simulations. In this report, we demonstrate that
Trp+ partitions into the lipid bilayer membrane to a greater degree
than Trp– by interacting with the ester linkage of a phosphatidylcholine
lipid, where it is stabilized by the electron withdrawing glycerol
functional group. These results are in agreement with tryptophan’s
known role as an anchor for transmembrane proteins, though the tendency
for binding of a positively charged tryptophan is surprising. We discuss
the implications of our results on the mechanisms of unassisted permeation
and penetration of small molecules within and across lipid bilayer
membranes based on molecular charge, shape, and molecular interactions
within the bilayer structure.
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28
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Chen F, Manandhar P, Ahmed MS, Chang S, Panday N, Zhang H, Moon JH, He J. Extracellular Surface Potential Mapping by Scanning Ion Conductance Microscopy Revealed Transient Transmembrane Pore Formation Induced by Conjugated Polymer Nanoparticles. Macromol Biosci 2018; 19:e1800271. [PMID: 30548770 DOI: 10.1002/mabi.201800271] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 11/24/2018] [Indexed: 12/30/2022]
Abstract
In-depth understanding of the biophysicochemical interactions at the nano-bio interface is important for basic cell biology and applications in nanomedicine and nanobiosensors. Here, the extracellular surface potential and topography changes of live cell membranes interacting with polymeric nanomaterials using a scanning ion conductance microscopy-based potential imaging technique are investigated. Two structurally similar amphiphilic conjugated polymer nanoparticles (CPNs) containing different functional groups (i.e., primary amine versus guanidine) are used to study incubation time and functional group-dependent extracellular surface potential and topographic changes. Transmembrane pores, which induce significant changes in potential, only appear transiently in the live cell membranes during the initial interactions. The cells are able to self-repair the damaged membrane and become resilient to prolonged CPN exposure. This study provides an important observation on how the cells interact with and respond to extracellular polymeric nanomaterials at the early stage. This study also demonstrates that extracellular surface potential imaging can provide a new insight to help understand the complicated interactions at the nano-bio interface and the following cellular responses.
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Affiliation(s)
- Feng Chen
- Department of Physics, Biomolecular Sciences Institute, Florida International University, FL, 33199, USA
| | - Prakash Manandhar
- Department of Chemistry and Biochemistry, Biomolecular Sciences Institute, Florida International University, FL, 33199, USA
| | - Md Salauddin Ahmed
- Department of Chemistry and Biochemistry, Biomolecular Sciences Institute, Florida International University, FL, 33199, USA
| | - Shuai Chang
- The State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan, 430081, China
| | - Namuna Panday
- Department of Physics, Biomolecular Sciences Institute, Florida International University, FL, 33199, USA
| | - Haiqian Zhang
- College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China
| | - Joong Ho Moon
- Department of Chemistry and Biochemistry, Biomolecular Sciences Institute, Florida International University, FL, 33199, USA
| | - Jin He
- Department of Physics, Biomolecular Sciences Institute, Florida International University, FL, 33199, USA
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29
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Faya M, Kalhapure RS, Dhumal D, Agrawal N, Omolo C, Akamanchi KG, Govender T. Antimicrobial cell penetrating peptides with bacterial cell specificity: pharmacophore modelling, quantitative structure activity relationship and molecular dynamics simulation. J Biomol Struct Dyn 2018; 37:2370-2380. [PMID: 30047310 DOI: 10.1080/07391102.2018.1484814] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Current research has shown cell-penetrating peptides and antimicrobial peptides (AMPs) as probable vectors for use in drug delivery and as novel antibiotics. It has been reported that the higher the therapeutic index (TI) the higher would be the bacterial cell penetrating ability. To the best of our knowledge, no in-silico study has been performed to determine bacterial cell specificity of the antimicrobial cell penetrating peptides (aCPP's) based on their TI. The aim of this study was to develop a quantitative structure activity relationship (QSAR) model, which can estimate antimicrobial potential and cell-penetrating ability of aCPPs against S. aureus, to confirm the relationship between the TI and aCPPs and to identify specific descriptors responsible for aCPPs penetrating ability. Molecular dynamics (MD) simulation was also performed to confirm the membrane insertion of the most active aCPPs obtained from the QSAR study. The most appropriate pharmacophore was identified to predict the aCPP's activity. The statistical results confirmed the validity of the model. The QSAR model was successful in identifying the optimal aCPP with high activity prediction and provided insights into the structural requirements to correlate their TI to cell penetrating ability. MD simulation of the best aCPP with 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) bilayer confirmed its interaction with the membrane and the C-terminal residues of the aCPP played a key role in membrane penetration. The strategy of combining QSAR and molecular dynamics, allowed for optimal estimation of ligand-target interaction and confirmed the importance of Trp and Lys in interacting with the POPC bilayer. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Mbuso Faya
- a Department of Pharmaceutical Sciences , University of KwaZulu-Natal , Private Bag , Durban , South Africa
| | - Rahul S Kalhapure
- a Department of Pharmaceutical Sciences , University of KwaZulu-Natal , Private Bag , Durban , South Africa
| | - Dinesh Dhumal
- b Department of Pharmaceutical Sciences and Technology , Institute of Chemical Technology , Mumbai , India
| | - Nikhil Agrawal
- a Department of Pharmaceutical Sciences , University of KwaZulu-Natal , Private Bag , Durban , South Africa
| | - Calvin Omolo
- a Department of Pharmaceutical Sciences , University of KwaZulu-Natal , Private Bag , Durban , South Africa
| | - Krishnacharya G Akamanchi
- b Department of Pharmaceutical Sciences and Technology , Institute of Chemical Technology , Mumbai , India
| | - Thirumala Govender
- a Department of Pharmaceutical Sciences , University of KwaZulu-Natal , Private Bag , Durban , South Africa
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30
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Abstract
Recent studies with murine models of cell-specific loss- or gain-of-function of FoxOs have provided novel insights into the function and signaling of these transcription factors on the skeleton. They have revealed that FoxO actions in chondrocytes are critical for normal skeletal development, and FoxO actions in cells of the osteoclast or osteoblast lineage greatly influence bone resorption and formation and, consequently, bone mass. FoxOs also act in osteoblast progenitors to inhibit Wnt signaling and bone formation. Additionally, FoxOs decrease bone resorption via direct antioxidant effects on osteoclasts and upregulation of the antiosteoclastogenic cytokine OPG in cells of the osteoblast lineage. Deacetylation of FoxOs by the NAD-dependent histone deacetylase Sirt1 in both osteoblasts and osteoclasts stimulates bone formation and inhibits bone resorption, making Sirt1 activators promising therapeutic agents for diseases of low bone mass. In this chapter, we review these advances and discuss their implications for the pathogenesis and treatment of estrogen deficiency-, Type 1 diabetes-, and age-related osteoporosis.
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Affiliation(s)
- Ha-Neui Kim
- Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Srividhya Iyer
- University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Rebecca Ring
- Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| | - Maria Almeida
- Center for Osteoporosis and Metabolic Bone Diseases, University of Arkansas for Medical Sciences, Little Rock, AR, United States; University of Arkansas for Medical Sciences, Little Rock, AR, United States.
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31
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Lee BL, Kuczera K. Simulating the free energy of passive membrane permeation for small molecules. MOLECULAR SIMULATION 2017. [DOI: 10.1080/08927022.2017.1407029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Brent L. Lee
- Department of Chemistry, The University of Kansas , Lawrence, KS, USA
| | - Krzysztof Kuczera
- Department of Chemistry, The University of Kansas , Lawrence, KS, USA
- Department of Molecular Biosciences, The University of Kansas , Lawrence, KS, USA
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32
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Gedawy A, Martinez J, Al-Salami H, Dass CR. Oral insulin delivery: existing barriers and current counter-strategies. J Pharm Pharmacol 2017; 70:197-213. [DOI: 10.1111/jphp.12852] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Accepted: 10/24/2017] [Indexed: 12/21/2022]
Abstract
Abstract
Objectives
The chronic and progressive nature of diabetes is usually associated with micro- and macrovascular complications where failure of pancreatic β-cell function and a general condition of hyperglycaemia is created. One possible factor is failure of the patient to comply with and adhere to the prescribed insulin due to the inconvenient administration route. This review summarizes the rationale for oral insulin administration, existing barriers and some counter-strategies trialled.
Key findings
Oral insulin mimics the physiology of endogenous insulin secreted by pancreas. Following the intestinal absorption of oral insulin, it reaches the liver at high concentration via the portal vein. Oral insulin on the other hand has the potential to protect pancreatic β-cells from autoimmune destruction. Structural modification, targeting a particular tissue/receptor, and the use of innovative pharmaceutical formulations such as nanoparticles represent strategies introduced to improve oral insulin bioavailability. They showed promising results in overcoming the hurdles facing oral insulin delivery, although delivery is far from ideal.
Summary
The use of advanced pharmaceutical technologies and further research in particulate carrier system delivery predominantly nanoparticle utilization would offer useful tools in delivering insulin via the oral route which in turn would potentially improve diabetic patient compliance to insulin and the overall management of diabetes.
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Affiliation(s)
- Ahmed Gedawy
- School of Pharmacy and Biomedical Science, Curtin University, Bentley, WA, Australia
| | - Jorge Martinez
- School of Pharmacy and Biomedical Science, Curtin University, Bentley, WA, Australia
| | - Hani Al-Salami
- School of Pharmacy and Biomedical Science, Curtin University, Bentley, WA, Australia
- Curtin Health Innovation Research Institute, Bentley, WA, Australia
| | - Crispin R Dass
- School of Pharmacy and Biomedical Science, Curtin University, Bentley, WA, Australia
- Curtin Health Innovation Research Institute, Bentley, WA, Australia
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33
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Lee MW, Han M, Bossa GV, Snell C, Song Z, Tang H, Yin L, Cheng J, May S, Luijten E, Wong GCL. Interactions between Membranes and "Metaphilic" Polypeptide Architectures with Diverse Side-Chain Populations. ACS NANO 2017; 11:2858-2871. [PMID: 28212487 DOI: 10.1021/acsnano.6b07981] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
At physiological conditions, most proteins or peptides can fold into relatively stable structures that present on their molecular surfaces specific chemical patterns partially smeared out by thermal fluctuations. These nanoscopically defined patterns of charge, hydrogen bonding, and/or hydrophobicity, along with their elasticity and shape stability (folded proteins have Young's moduli of ∼1 × 108 Pa), largely determine and limit the interactions of these molecules, such as molecular recognition and allosteric regulation. In this work, we show that the membrane-permeating activity of antimicrobial peptides (AMPs) and cell-penetrating peptides (CPPs) can be significantly enhanced using prototypical peptides with "molten" surfaces: metaphilic peptides with quasi-liquid surfaces and adaptable shapes. These metaphilic peptides have a bottlebrush-like architecture consisting of a rigid helical core decorated with mobile side chains that are terminated by cationic or hydrophobic groups. Computer simulations show that these flexible side chains can undergo significant rearrangement in response to different environments, giving rise to adaptable surface chemistry of the peptide. This quality makes it possible to control their hydrophobicity over a broad range while maintaining water solubility, unlike many AMPs and CPPs. Thus, we are able to show how the activity of these peptides is amplified by hydrophobicity and cationic charge, and rationalize these results using a quantitative mean-field theory. Computer simulations show that the shape-changing properties of the peptides and the resultant adaptive presentation of chemistry play a key enabling role in their interactions with membranes.
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Affiliation(s)
| | | | - Guilherme Volpe Bossa
- Department of Physics, North Dakota State University , Fargo, North Dakota 58108, United States
| | - Carly Snell
- Department of Physics, North Dakota State University , Fargo, North Dakota 58108, United States
| | - Ziyuan Song
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Haoyu Tang
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Lichen Yin
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Jianjun Cheng
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States
| | - Sylvio May
- Department of Physics, North Dakota State University , Fargo, North Dakota 58108, United States
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34
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Lee BL, Kuczera K, Middaugh CR, Jas GS. Permeation of the three aromatic dipeptides through lipid bilayers: Experimental and computational study. J Chem Phys 2016; 144:245103. [DOI: 10.1063/1.4954241] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Affiliation(s)
- Brent L. Lee
- Department of Chemistry, The University of Kansas, Lawrence, Kansas 66045, USA
| | - Krzysztof Kuczera
- Department of Chemistry, The University of Kansas, Lawrence, Kansas 66045, USA
- Department of Molecular Biosciences, The University of Kansas, Lawrence, Kansas 66045, USA
| | - C. Russell Middaugh
- Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, Kansas 66047, USA
| | - Gouri S. Jas
- Department of Pharmaceutical Chemistry, The University of Kansas, Lawrence, Kansas 66047, USA
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35
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Takechi-Haraya Y, Nadai R, Kimura H, Nishitsuji K, Uchimura K, Sakai-Kato K, Kawakami K, Shigenaga A, Kawakami T, Otaka A, Hojo H, Sakashita N, Saito H. Enthalpy-driven interactions with sulfated glycosaminoglycans promote cell membrane penetration of arginine peptides. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:1339-49. [DOI: 10.1016/j.bbamem.2016.03.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 02/12/2016] [Accepted: 03/17/2016] [Indexed: 12/16/2022]
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36
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He X, Lin M, Guo J, Qu Z, Xu F. Experimental and simulation studies of polyarginines across the membrane of giant unilamellar vesicles. RSC Adv 2016. [DOI: 10.1039/c6ra02420c] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Cell-penetrating peptides have widespread applications in biomedicine because of their capability to translocate across cell membranes alone or with cargos.
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Affiliation(s)
- XiaoCong He
- Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education
- School of Energy and Power Engineering
- Xi'an Jiaotong University
- Xi'an 710049
- P.R. China
| | - Min Lin
- Bioinspired Engineering and Biomechanics Center (BEBC)
- Xi'an Jiaotong University
- Xi'an 710049
- P.R. China
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education
| | - Jun Guo
- Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education
- School of Energy and Power Engineering
- Xi'an Jiaotong University
- Xi'an 710049
- P.R. China
| | - ZhiGuo Qu
- Key Laboratory of Thermo-Fluid Science and Engineering of Ministry of Education
- School of Energy and Power Engineering
- Xi'an Jiaotong University
- Xi'an 710049
- P.R. China
| | - Feng Xu
- Bioinspired Engineering and Biomechanics Center (BEBC)
- Xi'an Jiaotong University
- Xi'an 710049
- P.R. China
- The Key Laboratory of Biomedical Information Engineering of Ministry of Education
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37
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Cell-penetrating compounds preferentially bind glycosaminoglycans over plasma membrane lipids in a charge density- and stereochemistry-dependent manner. Biophys Chem 2015; 207:40-50. [DOI: 10.1016/j.bpc.2015.08.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 08/14/2015] [Accepted: 08/17/2015] [Indexed: 11/19/2022]
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38
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Coarse-grained molecular dynamics studies of the translocation mechanism of polyarginines across asymmetric membrane under tension. Sci Rep 2015; 5:12808. [PMID: 26235300 PMCID: PMC4522684 DOI: 10.1038/srep12808] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 07/09/2015] [Indexed: 12/19/2022] Open
Abstract
Understanding interactions between cell-penetrating peptides and biomembrane under tension can help improve drug delivery and elucidate mechanisms underlying fundamental cellular events. As far as the effect of membrane tension on translocation, it is generally thought that tension should disorder the membrane structure and weaken its strength, thereby facilitating penetration. However, our coarse-grained molecular dynamics simulation results showed that membrane tension can restrain polyarginine translocation across the asymmetric membrane and that this effect increases with increasing membrane tension. We also analyzed the structural properties and lipid topology of the tensed membrane to explain the phenomena. Simulation results provide important molecular information on the potential translocation mechanism of peptides across the asymmetric membrane under tension as well as new insights in drug and gene delivery.
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39
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Cardenas AE, Shrestha R, Webb LJ, Elber R. Membrane permeation of a peptide: it is better to be positive. J Phys Chem B 2015; 119:6412-20. [PMID: 25941740 DOI: 10.1021/acs.jpcb.5b02122] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A joint experimental and computational study investigates the translocation of a tryptophan molecule through a phospholipid membrane. Time dependent spectroscopy of the tryptophan side chain determines the rate of permeation into 150 nm phospholipid vesicles. Atomically detailed simulations are conducted to calculate the free energy profiles and the permeation coefficient. Different charging conditions of the peptide (positive, negative, or zwitterion) are considered. Both experiment and simulation reproduce the qualitative trend and suggest that the fastest permeation is when the tryptophan is positively charged. The permeation mechanism, which is revealed by molecular dynamics simulations, is of a translocation assisted by a local defect. The influence of long-range electrostatic interactions, such as the membrane dipole potential on the permeation process, is not significant.
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Affiliation(s)
- Alfredo E Cardenas
- †Institute for Computational Engineering and Sciences and ‡Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Rebika Shrestha
- †Institute for Computational Engineering and Sciences and ‡Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Lauren J Webb
- †Institute for Computational Engineering and Sciences and ‡Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
| | - Ron Elber
- †Institute for Computational Engineering and Sciences and ‡Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States
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40
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Herce HD, Garcia AE, Cardoso MC. Fundamental molecular mechanism for the cellular uptake of guanidinium-rich molecules. J Am Chem Soc 2014; 136:17459-67. [PMID: 25405895 PMCID: PMC4277769 DOI: 10.1021/ja507790z] [Citation(s) in RCA: 177] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
![]()
Guanidinium-rich
molecules, such as cell-penetrating peptides,
efficiently enter living cells in a non-endocytic energy-independent
manner and transport a wide range of cargos, including drugs and biomarkers.
The mechanism by which these highly cationic molecules efficiently
cross the hydrophobic barrier imposed by the plasma membrane remains
a fundamental open question. Here, a combination of computational
results and in vitro and live-cell experimental evidence reveals an
efficient energy-independent translocation mechanism for arginine-rich
molecules. This mechanism unveils the essential role of guanidinium
groups and two universal cell components: fatty acids and the cell
membrane pH gradient. Deprotonated fatty acids in contact with the
cell exterior interact with guanidinium groups, leading to a transient
membrane channel that facilitates the transport of arginine-rich peptides
toward the cell interior. On the cytosolic side, the fatty acids become
protonated, releasing the peptides and resealing the channel. This
fundamental mechanism appears to be universal across cells from different
species and kingdoms.
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Affiliation(s)
- Henry D Herce
- Department of Physics, Applied Physics and Astronomy and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute , Troy, New York 12180, United States
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41
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Herce HD, Rajan M, Lättig-Tünnemann G, Fillies M, Cardoso MC. A novel cell permeable DNA replication and repair marker. Nucleus 2014; 5:590-600. [PMID: 25484186 PMCID: PMC4615156 DOI: 10.4161/nucl.36290] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Proliferating Cell Nuclear Antigen (PCNA) is a key protein in DNA replication and repair. The dynamics of replication and repair in live cells is usually studied introducing translational fusions of PCNA. To obviate the need for transfection and bypass the problem of difficult to transfect and/or short lived cells, we have now developed a cell permeable replication and/or repair marker. The design of this marker has three essential molecular components: (1) an optimized artificial PCNA binding peptide; (2) a cell-penetrating peptide, derived from the HIV-1 Trans Activator of Transcription (TAT); (3) an in vivo cleavable linker, linking the two peptides. The resulting construct was taken up by human, hamster and mouse cells within minutes of addition to the media. Inside the cells, the cargo separated from the vector peptide and bound PCNA effectively. Both replication and repair sites could be directly labeled in live cells making it the first in vivo cell permeable peptide marker for these two fundamental cellular processes. Concurrently, we also introduced a quick peptide based PCNA staining method as an alternative to PCNA antibodies for immunofluorescence applications. In summary, we present here a versatile tool to instantaneously label repair and replication processes in fixed and live cells.
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Affiliation(s)
- Henry D Herce
- a Department of Biology , Technische Universität Darmstadt ; Darmstadt , Germany
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42
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Abstract
The transacting activator of transduction (TAT) protein plays a key role in the progression of AIDS. Studies have shown that a +8 charged sequence of amino acids in the protein, called the TAT peptide, enables the TAT protein to penetrate cell membranes. To probe mechanisms of binding and translocation of the TAT peptide into the cell, investigators have used phospholipid liposomes as cell membrane mimics. We have used the method of surface potential sensitive second harmonic generation (SHG), which is a label-free and interface-selective method, to study the binding of TAT to anionic 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-1'-rac-glycerol (POPG) and neutral 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) liposomes. It is the SHG sensitivity to the electrostatic field generated by a charged interface that enabled us to obtain the interfacial electrostatic potential. SHG together with the Poisson-Boltzmann equation yielded the dependence of the surface potential on the density of adsorbed TAT. We obtained the dissociation constants Kd for TAT binding to POPC and POPG liposomes and the maximum number of TATs that can bind to a given liposome surface. For POPC Kd was found to be 7.5 ± 2 μM, and for POPG Kd was 29.0 ± 4.0 μM. As TAT was added to the liposome solution the POPC surface potential changed from 0 mV to +37 mV, and for POPG it changed from -57 mV to -37 mV. A numerical calculation of Kd, which included all terms obtained from application of the Poisson-Boltzmann equation to the TAT liposome SHG data, was shown to be in good agreement with an approximated solution.
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43
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Virkki MT, Agrawal N, Edsbäcker E, Cristobal S, Elofsson A, Kauko A. Folding of Aquaporin 1: multiple evidence that helix 3 can shift out of the membrane core. Protein Sci 2014; 23:981-92. [PMID: 24777974 PMCID: PMC4088982 DOI: 10.1002/pro.2483] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Revised: 04/23/2014] [Accepted: 04/24/2014] [Indexed: 12/29/2022]
Abstract
The folding of most integral membrane proteins follows a two-step process: initially, individual transmembrane helices are inserted into the membrane by the Sec translocon. Thereafter, these helices fold to shape the final conformation of the protein. However, for some proteins, including Aquaporin 1 (AQP1), the folding appears to follow a more complicated path. AQP1 has been reported to first insert as a four-helical intermediate, where helix 2 and 4 are not inserted into the membrane. In a second step, this intermediate is folded into a six-helical topology. During this process, the orientation of the third helix is inverted. Here, we propose a mechanism for how this reorientation could be initiated: first, helix 3 slides out from the membrane core resulting in that the preceding loop enters the membrane. The final conformation could then be formed as helix 2, 3, and 4 are inserted into the membrane and the reentrant regions come together. We find support for the first step in this process by showing that the loop preceding helix 3 can insert into the membrane. Further, hydrophobicity curves, experimentally measured insertion efficiencies and MD-simulations suggest that the barrier between these two hydrophobic regions is relatively low, supporting the idea that helix 3 can slide out of the membrane core, initiating the rearrangement process.
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Affiliation(s)
- Minttu T Virkki
- Department of Biochemistry and Biophysics and Science for Life Laboratory, Stockholm UniversitySolna, SE-171 21, Sweden
| | - Nitin Agrawal
- Department of Biosciences, Biochemistry, Åbo AkademiTurku, FI-20520, Finland
| | - Elin Edsbäcker
- Department of Biochemistry and Biophysics and Science for Life Laboratory, Stockholm UniversitySolna, SE-171 21, Sweden
| | - Susana Cristobal
- Department of Clinical and Experimental Medicine, Cell Biology, Faculty of Health Science, Linköping UniversityLinköping, Sweden
- Department of Physiology, IKERBASQUE, Basque Foundation for Science, Faculty of Medicine and Dentistry, University of the Basque CountryLeioa, Spain
| | - Arne Elofsson
- Department of Biochemistry and Biophysics and Science for Life Laboratory, Stockholm UniversitySolna, SE-171 21, Sweden
| | - Anni Kauko
- Department of Biosciences, Biochemistry, Åbo AkademiTurku, FI-20520, Finland
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Abstract
Delivery of peptides by the oral route greatly appeals due to commercial, patient convenience and scientific arguments. While there are over 60 injectable peptides marketed worldwide, and many more in development, most delivery strategies do not yet adequately overcome the barriers to oral delivery. Peptides are sensitive to chemical and enzymatic degradation in the intestine, and are poorly permeable across the intestinal epithelium due to sub-optimal physicochemical properties. A successful oral peptide delivery technology should protect potent peptides from presystemic degradation and improve epithelial permeation to achieve a target oral bioavailability with acceptable intra-subject variability. This review provides a comprehensive up-to-date overview of the current status of oral peptide delivery with an emphasis on patented formulations that are yielding promising clinical data.
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45
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Li Z, Ha J, Zou T, Gu L. Fabrication of coated bovine serum albumin (BSA)-epigallocatechin gallate (EGCG) nanoparticles and their transport across monolayers of human intestinal epithelial Caco-2 cells. Food Funct 2014; 5:1278-85. [PMID: 24741679 DOI: 10.1039/c3fo60500k] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The bovine serum albumin (BSA)-epigallocatechin gallate (EGCG) nanoparticles were fabricated using a desolvation method, and coated with poly-ε-lysine or chitosan. BSA-EGCG nanoparticles (BEN), poly-ε-lysine coated BSA-EGCG nanoparticles (PBEN), and chitosan coated BSA-EGCG nanoparticles (CBEN) had a spherical morphology and a size of 186, 259, and 300 nm, respectively. The loading efficiency of EGCG in these nanoparticles was 32.3%, 35.4%, and 32.7%, whereas the loading capacity was 18.9%, 17.0%, and 16.0% (w/w), respectively. Poly-ε-lysine or chitosan coating prevented the aggregation of nanoparticles at pH 4.5-5.0. However, they caused particle aggregation at pH 6.5-7.0. BEN had negative zeta-potentials between pH 4.5 and 6.0. Poly-ε-lysine or chitosan coating changed the zeta-potentials to positive. The release study of EGCG from the nanoparticles in the simulated gastric or intestinal fluid with or without digestive enzymes showed that poly-ε-lysine and chitosan coatings delayed EGCG release from the nanoparticles. Poly-ε-lysine or chitosan coating improved the stability of EGCG during storage at 60 °C compared with EGCG in the uncoated particles. EGCG in BEN, PBEN, and CBEN had a decreasing apparent permeability coefficient (Papp) on Caco-2 monolayers, whereas pure EGCG showed relatively stable Papp during the incubation over time. EGCG in CBEN showed significantly higher Papp, suggesting that chitosan coated BSA-EGCG nanoparticles may improve the absorption of EGCG.
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Affiliation(s)
- Zheng Li
- Food Science and Human Nutrition Department, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611, USA.
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46
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Guzmán F, Marshall S, Ojeda C, Albericio F, Carvajal-Rondanelli P. Inhibitory effect of short cationic homopeptides against gram-positive bacteria. J Pept Sci 2013; 19:792-800. [PMID: 24243601 DOI: 10.1002/psc.2578] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 09/25/2013] [Accepted: 10/01/2013] [Indexed: 01/26/2023]
Abstract
In the selection or design of antimicrobial peptides, the key role played by cationic amino acids and chain length on the inhibitory potency and specificity is not clear. A fundamental study was conducted using chemically synthesized homopeptides of L-Lys and L-Arg ranging from 7 to 14 residues. Their effect on growth inhibition was evaluated over a wide range of Gram-positive bacteria at different levels of concentration. Interestingly, at lower concentrations (10 μM), Lys homopeptides with odd number of residues, especially with 11 residues, showed a broader inhibitory activity than those with even number of residues. At higher peptide concentrations (>20 μM), the inhibitory activity of Lys homopeptides was directly related to the number of residues in the chain. In contrast, Arg homopeptides, at lower concentrations, did not exhibit a defined pattern of bacterial inhibition related to the number of residues; however, at higher concentrations (>20 μM), the inhibitory effects were more pronounced. Lys homopeptides at concentrations up to 300 μM showed a remarkably lower toxicity against CHSE-214 cells. Arg homopeptides exhibited negligible cytotoxicity up to chain length of 11 residues at concentrations lower than 100 μM, but an abrupt increase in toxicity resulted when the peptide chain length reached 12 amino acid residues and higher concentrations. All synthesized homopeptides displayed characteristic polyproline II helix conformation in both buffer and liposomes, as shown by CD spectroscopy. This result suggests that short Lys homopeptides with an odd number of residues (9 and 11) have a broad spectrum of activity against Gram-positive bacterial cells compared with Arg homopeptides, which in turn showed a considerably higher selectivity toward those cells. By investigating the differences between Lys and Arg homopeptides, this study contributes to the understanding of their mechanism of growth inhibition and selectivity. Thus, it provides further guidelines for a rational design of short antimicrobial peptides.
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Affiliation(s)
- Fanny Guzmán
- Núcleo de Biotecnología de Curauma, Pontificia Universidad Católica de Valparaíso, Avenida Brasil 2950, Valparaíso, Chile and Fraunhofer Chile Research Foundation, Santiago, Chile
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47
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Li L, Vorobyov I, Allen TW. The different interactions of lysine and arginine side chains with lipid membranes. J Phys Chem B 2013; 117:11906-20. [PMID: 24007457 DOI: 10.1021/jp405418y] [Citation(s) in RCA: 213] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The basic amino acids lysine (Lys) and arginine (Arg) play important roles in membrane protein activity, the sensing of membrane voltages, and the actions of antimicrobial, toxin, and cell-penetrating peptides. These roles are thought to stem from the strong interactions and disruptive influences of these amino acids on lipid membranes. In this study, we employ fully atomistic molecular dynamics simulations to observe, quantify, and compare the interactions of Lys and Arg with saturated phosphatidylcholine membranes of different thickness. We make use of both charged (methylammonium and methylguanidinium) and neutral (methylamine and methylguanidine) analogue molecules, as well as Lys and Arg side chains on transmembrane helix models. We find that the free energy barrier experienced by a charged Lys crossing the membrane is strikingly similar to that of a charged Arg (to within 2 kcal/mol), despite the two having different chemistries, H-bonding capability, and hydration free energies that differ by ∼10 kcal/mol. In comparison, the barrier for neutral Arg is higher than that for neutral Lys by around 5 kcal/mol, being more selective than that for the charged species. This can be explained by the different transport mechanisms for charged or neutral amino acid side chains in the membrane, involving membrane deformations or simple dehydration, respectively. As a consequence, we demonstrate that Lys would be deprotonated in the membrane, whereas Arg would maintain its charge. Our simulations also reveal that Arg attracts more phosphate and water in the membrane, and can form extensive H-bonding with its five H-bond donors to stabilize Arg-phosphate clusters. This leads to enhanced interfacial binding and membrane perturbations, including the appearance of a trans-membrane pore in a thinner membrane. These results highlight the special role played by Arg as an amino acid to bind to, disrupt, and permeabilize lipid membranes, as well as to sense voltages for a range of peptide and protein activities in nature and in engineered bionanodevices.
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Affiliation(s)
- Libo Li
- Department of Chemistry, University of California, Davis , Davis, California 95616, United States
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48
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Hu Y, Ou S, Patel S. Free energetics of arginine permeation into model DMPC lipid bilayers: coupling of effective counterion concentration and lateral bilayer dimensions. J Phys Chem B 2013; 117:11641-53. [PMID: 23888915 DOI: 10.1021/jp404829y] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Mechanisms and underlying thermodynamic determinants of translocation of charged cationic peptides such as cell-penetrating peptides across the cellular membrane continue to receive much attention. Two widely held views include endocytotic and non-endocytotic (diffusive) processes of permeant transfer across the bilayer. Considering a purely diffusive process, we consider the free energetics of translocation of a monoarginine peptide mimic across a model DMPC bilayer. We compute potentials of mean force for the transfer of a charged monoarginine peptide unit from water to the center of a 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) model lipid bilayer. We use fully atomistic molecular dynamics simulations coupled with the adaptive biasing force (ABF) method for free energy estimation. The estimated potential of mean force difference from bulk to bilayer center is 6.94 ± 0.28 kcal/mol. The order of magnitude of this prediction is consistent with past experimental estimates of arginine partitioning into physiological bilayers in the context of translocon-based experiments, though the correlation between the bench and computer experiments is not unambiguous. Moreover, the present value is roughly one-half of previous estimates based on all-atom molecular dynamics free energy calculations. We trace the differences between the present and earlier calculations to system sizes used in the simulations and the dependence of the contributions to the free energy from various system components (water, lipids, ions, peptide) on overall system size. By varying the bilayer lateral dimensions in simulations using only sufficient numbers of counterions to maintain overall system charge neutrality, we find the possibility of an inherent convergent transfer free energy value.
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Affiliation(s)
- Yuan Hu
- Department of Chemistry and Biochemistry, University of Delaware , Newark, Delaware 19716, United States
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49
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Lahmer RA, Jones DL, Townsend S, Baker S, Williams AP. Susceptibility ofEscherichia coliO157 to chitosan-arginine in beef liquid purge is affected by bacterial cell growth phase. Int J Food Sci Technol 2013. [DOI: 10.1111/ijfs.12331] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Rabya A. Lahmer
- School of Environment, Natural Resources & Geography; College of Natural Sciences; Bangor University; Bangor LL57 2UW UK
| | - David L. Jones
- School of Environment, Natural Resources & Geography; College of Natural Sciences; Bangor University; Bangor LL57 2UW UK
| | - Stacy Townsend
- Synedgen, Inc.; 1420 N Claremont Blvd Suite 105D Claremont CA 91711 USA
| | - Shenda Baker
- Synedgen, Inc.; 1420 N Claremont Blvd Suite 105D Claremont CA 91711 USA
| | - Arwel Prysor Williams
- School of Environment, Natural Resources & Geography; College of Natural Sciences; Bangor University; Bangor LL57 2UW UK
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50
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Nikitenko NA, Prassolov VS. Non-Viral Delivery and Therapeutic Application of Small Interfering RNAs. Acta Naturae 2013; 5:35-53. [PMID: 24303201 PMCID: PMC3848066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
RNA interference (RNAi) is a powerful method used for gene expression regulation. The increasing knowledge about the molecular mechanism of this phenomenon creates new avenues for the application of the RNAi technology in the treatment of various human diseases. However, delivery of RNA interference mediators, small interfering RNAs (siRNAs), to target cells is a major hurdle. Effective and safe pharmacological use of siRNAs requires carriers that can deliver siRNA to its target site and the development of methods for protection of these fragile molecules from in vivo degradation. This review summarizes various strategies for siRNA delivery, including chemical modification and non-viral approaches, such as the polymer-based, peptide-based, lipid-based techniques, and inorganic nanosystems. The advantages, disadvantages, and prospects for the therapeutic application of these methods are also examined in this paper.
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Affiliation(s)
- N. A. Nikitenko
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilova Str., 32, Moscow, Russia, 119991
| | - V. S. Prassolov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilova Str., 32, Moscow, Russia, 119991
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