1
|
Mihailescu M, Sorci M, Seckute J, Silin VI, Hammer J, Perrin BS, Hernandez JI, Smajic N, Shrestha A, Bogardus KA, Greenwood AI, Fu R, Blazyk J, Pastor RW, Nicholson LK, Belfort G, Cotten ML. Structure and Function in Antimicrobial Piscidins: Histidine Position, Directionality of Membrane Insertion, and pH-Dependent Permeabilization. J Am Chem Soc 2019; 141:9837-9853. [PMID: 31144503 DOI: 10.1021/jacs.9b00440] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Piscidins are histidine-enriched antimicrobial peptides that interact with lipid bilayers as amphipathic α-helices. Their activity at acidic and basic pH in vivo makes them promising templates for biomedical applications. This study focuses on p1 and p3, both 22-residue-long piscidins with 68% sequence identity. They share three histidines (H3, H4, and H11), but p1, which is significantly more permeabilizing, has a fourth histidine (H17). This study investigates how variations in amphipathic character associated with histidines affect the permeabilization properties of p1 and p3. First, we show that the permeabilization ability of p3, but not p1, is strongly inhibited at pH 6.0 when the conserved histidines are partially charged and H17 is predominantly neutral. Second, our neutron diffraction measurements performed at low water content and neutral pH indicate that the average conformation of p1 is highly tilted, with its C-terminus extending into the opposite leaflet. In contrast, p3 is surface bound with its N-terminal end tilted toward the bilayer interior. The deeper membrane insertion of p1 correlates with its behavior at full hydration: an enhanced ability to tilt, bury its histidines and C-terminus, induce membrane thinning and defects, and alter membrane conductance and viscoelastic properties. Furthermore, its pH-resiliency relates to the neutral state favored by H17. Overall, these results provide mechanistic insights into how differences in the histidine content and amphipathicity of peptides can elicit different directionality of membrane insertion and pH-dependent permeabilization. This work features complementary methods, including dye leakage assays, NMR-monitored titrations, X-ray and neutron diffraction, oriented CD, molecular dynamics, electrochemical impedance spectroscopy, surface plasmon resonance, and quartz crystal microbalance with dissipation.
Collapse
Affiliation(s)
- Mihaela Mihailescu
- Institute for Bioscience and Biotechnology Research , University of Maryland , Rockville , Maryland 20850 , United States
| | - Mirco Sorci
- Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies , Rensselaer Polytechnic Institute , Troy , New York 12180 , United States
| | - Jolita Seckute
- Department of Molecular Biology and Genetics , Cornell University , Ithaca , New York 14853 , United States
| | - Vitalii I Silin
- Institute for Bioscience and Biotechnology Research , University of Maryland , Rockville , Maryland 20850 , United States
| | - Janet Hammer
- Department of Biomedical Sciences , Ohio University , Athens , Ohio 45701 , United States
| | - B Scott Perrin
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute , National Institutes of Health , Bethesda , Maryland 20892 , United States
| | - Jorge I Hernandez
- Department of Bioengineering , Clemson University , Clemson , South Carolina 29634 , United States
| | - Nedzada Smajic
- Department of Chemistry , Hamilton College , Clinton , New York 13323 , United States
| | - Akritee Shrestha
- Department of Chemistry , Hamilton College , Clinton , New York 13323 , United States
| | - Kimberly A Bogardus
- Department of Chemistry , Hamilton College , Clinton , New York 13323 , United States
| | - Alexander I Greenwood
- Department of Applied Science , College of William and Mary , Williamsburg , Virginia 23185 , United States
| | - Riqiang Fu
- National High Magnetic Field Laboratory , Tallahassee , Florida 32310 , United States
| | - Jack Blazyk
- Department of Biomedical Sciences , Ohio University , Athens , Ohio 45701 , United States
| | - Richard W Pastor
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute , National Institutes of Health , Bethesda , Maryland 20892 , United States
| | - Linda K Nicholson
- Department of Molecular Biology and Genetics , Cornell University , Ithaca , New York 14853 , United States
| | - Georges Belfort
- Department of Chemical and Biological Engineering and Center for Biotechnology and Interdisciplinary Studies , Rensselaer Polytechnic Institute , Troy , New York 12180 , United States
| | - Myriam L Cotten
- Department of Applied Science , College of William and Mary , Williamsburg , Virginia 23185 , United States
| |
Collapse
|
3
|
Pan R, Xu W, Ding Y, Lu S, Chen P. Uptake Mechanism and Direct Translocation of a New CPP for siRNA Delivery. Mol Pharm 2016; 13:1366-74. [PMID: 26937821 DOI: 10.1021/acs.molpharmaceut.6b00030] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Since their development, cell-penetrating peptides (CPPs) have been used as delivery vehicles for various genetic or therapeutic agents; however, the uptake mechanisms of CPPs and the delivery details are still unclear. Understanding the mechanisms of cellular internalization of CPPs facilitate their development of CPPs as gene delivery vectors. In the present study, we evaluated the internalization process of a previously designed CPP, STR-KV, complexed with small interference RNA (siRNA) targeting at the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene. Using heparin treatment and chemical endocytic inhibitors, we elucidated that the electrostatic interaction of STR-KV/siRNA complex with heparin sulfate proteoglycans at the cell membrane surface triggered the energy-independent uptake of the majority of the complexes, which most likely through a direct translocation pathway. The intracellular trafficking and internalization kinetics observed by confocal microscopy also confirmed that the complex was uptaken through a nonendocytic pathway.
Collapse
Affiliation(s)
- Ran Pan
- Department of Chemical Engineering, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada.,Waterloo Institute for Nanotechnology, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
| | - Wen Xu
- Department of Chemical Engineering, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada.,Waterloo Institute for Nanotechnology, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
| | - Yong Ding
- Department of Chemical Engineering, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada.,Waterloo Institute for Nanotechnology, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
| | - Sheng Lu
- Department of Chemical Engineering, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada.,Waterloo Institute for Nanotechnology, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
| | - P Chen
- Department of Chemical Engineering, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada.,Waterloo Institute for Nanotechnology, University of Waterloo , Waterloo, Ontario N2L 3G1, Canada
| |
Collapse
|
4
|
Ingrao D, Majdoul S, Seye AK, Galy A, Fenard D. Concurrent measures of fusion and transduction efficiency of primary CD34+ cells with human immunodeficiency virus 1-based lentiviral vectors reveal different effects of transduction enhancers. Hum Gene Ther Methods 2013; 25:48-56. [PMID: 24152219 DOI: 10.1089/hgtb.2013.090] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Lentiviral vectors (LVs) are used for various gene transfer applications, notably for hematopoietic gene therapy, but methods are lacking for precisely evaluating parameters that control the efficiency of transduction in relation to the entry of vectors into target cells. We adapted a fluorescence resonance energy transfer-based human immunodeficiency virus-1 fusion assay to measure the entry of nonreplicative recombinant LVs in various cell types, including primary human hematopoietic stem progenitor cells (HSPCs), and to quantify the level of transduction of the same initially infected cells. The assay utilizes recombinant LVs containing β-lactamase (BLAM)-Vpr chimeric proteins (BLAM-LVs) and encoding a truncated form of the low-affinity nerve growth factor receptor (ΔNGFR). After infection of target cells with BLAM-LVs, the vector entry rapidly leads to BLAM-Vpr release into the cytoplasm, which is measured by cleavage of a fluorescent substrate using flow cytometry. Parallel cultures of the same infected cells show transduction efficiency resulting from ΔNGFR expression. This LV-based fusion/transduction assay is a dynamic and versatile tool, revealing, for instance, the postentry restrictions of LVs known to occur in cells of hematopoietic origin, especially human HSPCs. Furthermore, this BLAM-LV assay allowed us to evaluate the effect of cytokine prestimulation of HSPCs on the entry step of LVs. The assay also shows that transduction enhancers such as Vectofusin-1 or Retronectin can partially relieve the postentry block, but their effects differ in how they promote LV entry. In conclusion, one such assay should be useful to study hematopoietic postentry restrictions directed against LVs and therefore should allow improvements in various LV-based gene therapy protocols.
Collapse
|