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Dual functions of the human antimicrobial peptide LL-37-Target membrane perturbation and host cell cargo delivery.

Zhang, X; Oglecka, K; Sandgren, S; Belting, Mattias LU ; Esbjörner, EK; Nordén, B and Gräslund, A (2010) In Biochimica et Biophysica Acta - Biomembranes 1798(12). p.2201-2208
Abstract
The mechanisms behind target vs. host cell recognition of the human antimicrobial peptide LL-37 remain ill-defined. Here, we have investigated the membrane disruption capacity of LL-37 using large unilamellar vesicles (LUVs) composed of varying mixtures of POPC, POPG and cholesterol to mimic target and host membranes respectively. We show that LL-37 is unable to induce leakage of entrapped calcein from zwitterionic POPC LUVs, whereas leakage from LUVs partially composed of POPG is fast and efficient. In accordance with typical antimicrobial peptide behavior, cholesterol diminished LL-37 induced leakage. By using linear dichroism and flow oriented LUVs, we found that LL-37 orients with the axis of its induced alpha-helix parallel to the... (More)
The mechanisms behind target vs. host cell recognition of the human antimicrobial peptide LL-37 remain ill-defined. Here, we have investigated the membrane disruption capacity of LL-37 using large unilamellar vesicles (LUVs) composed of varying mixtures of POPC, POPG and cholesterol to mimic target and host membranes respectively. We show that LL-37 is unable to induce leakage of entrapped calcein from zwitterionic POPC LUVs, whereas leakage from LUVs partially composed of POPG is fast and efficient. In accordance with typical antimicrobial peptide behavior, cholesterol diminished LL-37 induced leakage. By using linear dichroism and flow oriented LUVs, we found that LL-37 orients with the axis of its induced alpha-helix parallel to the membrane surface in POPC:POPG (7:3) LUVs. In the same system, we also observed a time-dependent increase of the parallel alpha-helix LD signal on timescales corresponding to the leakage kinetics. The increased LD may be connected to a peptide translocation step, giving rise to mass balance across the membrane. This could end the leakage process before it is complete, similar to what we have observed. Confocal microscopy studies of eukaryotic cells show that LL-37 is able to mediate the cell delivery of non-covalently linked fluorescent oligonucleotides, in agreement with earlier studies on delivery of plasmid DNA (Sandgren et al., J. Biol. Chem. 279 (2004) 17951). These observations highlight the potential dual functions of LL-37 as an antimicrobial agent against bacterial target cells and a cell-penetrating peptide that can deliver nucleic acids into the host cells. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
LL-37, Antimicrobial peptide, Calcein leakage, CD, LD, Confocal microscopy, Heparan sulphate
in
Biochimica et Biophysica Acta - Biomembranes
volume
1798
issue
12
pages
2201 - 2208
publisher
Elsevier
external identifiers
  • wos:000284392900004
  • scopus:77958124580
ISSN
0005-2736
DOI
10.1016/j.bbamem.2009.12.011
language
English
LU publication?
yes
id
3aa481c8-a503-47d6-b4c3-1c98c7a92703 (old id 1543608)
date added to LUP
2012-01-19 10:57:00
date last changed
2018-06-10 04:10:16
@article{3aa481c8-a503-47d6-b4c3-1c98c7a92703,
  abstract     = {The mechanisms behind target vs. host cell recognition of the human antimicrobial peptide LL-37 remain ill-defined. Here, we have investigated the membrane disruption capacity of LL-37 using large unilamellar vesicles (LUVs) composed of varying mixtures of POPC, POPG and cholesterol to mimic target and host membranes respectively. We show that LL-37 is unable to induce leakage of entrapped calcein from zwitterionic POPC LUVs, whereas leakage from LUVs partially composed of POPG is fast and efficient. In accordance with typical antimicrobial peptide behavior, cholesterol diminished LL-37 induced leakage. By using linear dichroism and flow oriented LUVs, we found that LL-37 orients with the axis of its induced alpha-helix parallel to the membrane surface in POPC:POPG (7:3) LUVs. In the same system, we also observed a time-dependent increase of the parallel alpha-helix LD signal on timescales corresponding to the leakage kinetics. The increased LD may be connected to a peptide translocation step, giving rise to mass balance across the membrane. This could end the leakage process before it is complete, similar to what we have observed. Confocal microscopy studies of eukaryotic cells show that LL-37 is able to mediate the cell delivery of non-covalently linked fluorescent oligonucleotides, in agreement with earlier studies on delivery of plasmid DNA (Sandgren et al., J. Biol. Chem. 279 (2004) 17951). These observations highlight the potential dual functions of LL-37 as an antimicrobial agent against bacterial target cells and a cell-penetrating peptide that can deliver nucleic acids into the host cells.},
  author       = {Zhang, X and Oglecka, K and Sandgren, S and Belting, Mattias and Esbjörner, EK and Nordén, B and Gräslund, A},
  issn         = {0005-2736},
  keyword      = {LL-37,Antimicrobial peptide,Calcein leakage,CD,LD,Confocal microscopy,Heparan sulphate},
  language     = {eng},
  number       = {12},
  pages        = {2201--2208},
  publisher    = {Elsevier},
  series       = {Biochimica et Biophysica Acta - Biomembranes},
  title        = {Dual functions of the human antimicrobial peptide LL-37-Target membrane perturbation and host cell cargo delivery.},
  url          = {http://dx.doi.org/10.1016/j.bbamem.2009.12.011},
  volume       = {1798},
  year         = {2010},
}