2
|
Sterling JD, Jiang W, Botello-Smith WM, Luo YL. Ion Pairing and Dielectric Decrement in Glycosaminoglycan Brushes. J Phys Chem B 2021; 125:2771-2780. [PMID: 33662212 DOI: 10.1021/acs.jpcb.0c11571] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Cell-surface polysaccharides are essential to many aspects of physiology, serving as a highly conserved evolutionary feature of life and as an important part of the innate immune system in mammals. Here, as simplified biophysical models of these sugar coatings, we present results of molecular dynamics simulations of hyaluronic acid and heparin brushes that show important effects of ion pairing, water dielectric decrease, and coion exclusion. As in prior studies of macromolecular crowding under physiologically relevant salt concentrations, our results show equilibria with electroneutrality attained through screening and pairing of brush anionic charges by monovalent cations at the atomistic detail. Most surprising is the reversal of the Donnan potential obtained from both nonpolarizable and Drude polarizable force fields, in contrast to what would be expected based on electrostatic Boltzmann partitioning alone. Water dielectric decrement within the brush domain is also associated with Born hydration-driven cation exclusion from the brush. We observe that the primary partition energy attracting cations to attain brush electroneutrality is the ion pairing or salt-bridge energy. Potassium and sodium pairings to glycosaminoglycan carboxylates and sulfates show similar abundance of contact-pairing and solvent-separated pairing. We conclude that in these crowded macromolecular brushes, ion-pairing, Born-hydration, and electrostatic potential energies all contribute to attain electroneutrality and should therefore contribute in mean-field models to accurately represent brush electrostatics.
Collapse
Affiliation(s)
- James D Sterling
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, 535 Watson Dr., Claremont, California 91711, United States
| | - Wenjuan Jiang
- College of Pharmacy, Western University of Health Sciences, 309 E. Second Street, Pomona, California 91766, United States
| | - Wesley M Botello-Smith
- College of Pharmacy, Western University of Health Sciences, 309 E. Second Street, Pomona, California 91766, United States
| | - Yun L Luo
- College of Pharmacy, Western University of Health Sciences, 309 E. Second Street, Pomona, California 91766, United States
| |
Collapse
|
3
|
Fernandez-Petty CM, Hughes GW, Bowers HL, Watson JD, Rosen BH, Townsend SM, Santos C, Ridley CE, Chu KK, Birket SE, Li Y, Leung HM, Mazur M, Garcia BA, Evans TIA, Libby EF, Hathorne H, Hanes J, Tearney GJ, Clancy JP, Engelhardt JF, Swords WE, Thornton DJ, Wiesmann WP, Baker SM, Rowe SM. A glycopolymer improves vascoelasticity and mucociliary transport of abnormal cystic fibrosis mucus. JCI Insight 2019; 4:125954. [PMID: 30996141 DOI: 10.1172/jci.insight.125954] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 02/28/2019] [Indexed: 01/05/2023] Open
Abstract
Cystic fibrosis (CF) is characterized by increased mucus viscosity and delayed mucociliary clearance that contributes to progressive decline of lung function. Mucus in the respiratory and GI tract is excessively adhesive in the presence of airway dehydration and excess extracellular Ca2+ upon mucin release, promoting hyperviscous, densely packed mucins characteristic of CF. Therapies that target mucins directly through ionic interactions remain unexploited. Here we show that poly (acetyl, arginyl) glucosamine (PAAG), a polycationic biopolymer suitable for human use, interacts directly with mucins in a Ca2+-sensitive manner to reduce CF mucus viscoelasticity and improve its transport. Notably, PAAG induced a linear structure of purified MUC5B and altered its sedimentation profile and viscosity, indicative of proper mucin expansion. In vivo, PAAG nebulization improved mucociliary transport in CF rats with delayed mucus clearance, and cleared mucus plugging in CF ferrets. This study demonstrates the potential use of a synthetic glycopolymer PAAG as a molecular agent that could benefit patients with a broad array of mucus diseases.
Collapse
Affiliation(s)
| | - Gareth W Hughes
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, United Kingdom
| | - Hannah L Bowers
- Department of Medicine, University of Alabama at Birmingham (UAB), Birmingham, Alabama, USA
| | - John D Watson
- Department of Medicine, University of Alabama at Birmingham (UAB), Birmingham, Alabama, USA
| | - Bradley H Rosen
- Department of Anatomy & Cell Biology and.,Department of Medicine, University of Iowa, Iowa City, Iowa, USA
| | | | | | - Caroline E Ridley
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, United Kingdom
| | - Kengyeh K Chu
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, USA.,Department of Dermatology, Massachusetts General Hospital, Boston, Massachusetts, USA,Harvard Medical School, Boston, Massachusetts, USA.,Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts, USA.,Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Susan E. Birket
- Department of Medicine, University of Alabama at Birmingham (UAB), Birmingham, Alabama, USA.,Gregory Fleming James Cystic Fibrosis Research Center
| | - Yao Li
- Department of Medicine, University of Alabama at Birmingham (UAB), Birmingham, Alabama, USA.,Gregory Fleming James Cystic Fibrosis Research Center
| | - Hui Min Leung
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, USA.,Department of Dermatology, Massachusetts General Hospital, Boston, Massachusetts, USA,Harvard Medical School, Boston, Massachusetts, USA.,Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts, USA.,Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Marina Mazur
- Gregory Fleming James Cystic Fibrosis Research Center
| | - Bryan A Garcia
- Department of Medicine, University of Alabama at Birmingham (UAB), Birmingham, Alabama, USA.,Gregory Fleming James Cystic Fibrosis Research Center
| | | | | | - Heather Hathorne
- Gregory Fleming James Cystic Fibrosis Research Center,Department of Pediatrics, UAB, Birmingham, Alabama, USA
| | - Justin Hanes
- Center for Nanomedicine and Departments of Biomedical Engineering, Chemical & Biomolecular Sciences, Johns Hopkins University, Baltimore, Maryland, USA
| | - Guillermo J Tearney
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts, USA.,Department of Dermatology, Massachusetts General Hospital, Boston, Massachusetts, USA,Harvard Medical School, Boston, Massachusetts, USA.,Harvard-MIT Division of Health Sciences and Technology, Cambridge, Massachusetts, USA.,Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - John P Clancy
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
| | - John F Engelhardt
- Department of Anatomy & Cell Biology and.,Department of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - William E Swords
- Department of Medicine, University of Alabama at Birmingham (UAB), Birmingham, Alabama, USA.,Gregory Fleming James Cystic Fibrosis Research Center
| | - David J Thornton
- Wellcome Trust Centre for Cell-Matrix Research, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, United Kingdom
| | | | | | - Steven M Rowe
- Department of Medicine, University of Alabama at Birmingham (UAB), Birmingham, Alabama, USA.,Gregory Fleming James Cystic Fibrosis Research Center,Department of Pediatrics, UAB, Birmingham, Alabama, USA.,Department of Cell Developmental & Integrative Biology, UAB, Birmingham, Alabama, USA
| |
Collapse
|