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Dynamic light scattering and fluorescence study of the interaction between double-stranded DNA and poly(amido amine) dendrimers

Ainalem, Marie-Louise LU ; Schillén, Karin LU and Nylander, Tommy LU (2007) In Biomacromolecules 8(5). p.1557-1563
Abstract
The interaction between a cationic poly(amido amine) (PAMAM) dendrimer of generation 4 and double-stranded salmon sperm DNA in 10 mM NaBr solution has been investigated using dynamic light scattering (DLS) and steady-state fluorescence spectroscopy. The structural parameters of the formed aggregates as well as the complex formation process were studied in dilute solutions. When DNA is mixed with PAMAM dendrimers, it undergoes a transition from a semiflexible coil to a more compact conformation due to the electrostatic interaction present between the cationic dendrimer and the anionic polyelectrolyte. The DLS results reveal that one salmon sperm DNA molecule forms a discrete aggregate in dilute solution with several PAMAM dendrimers with a... (More)
The interaction between a cationic poly(amido amine) (PAMAM) dendrimer of generation 4 and double-stranded salmon sperm DNA in 10 mM NaBr solution has been investigated using dynamic light scattering (DLS) and steady-state fluorescence spectroscopy. The structural parameters of the formed aggregates as well as the complex formation process were studied in dilute solutions. When DNA is mixed with PAMAM dendrimers, it undergoes a transition from a semiflexible coil to a more compact conformation due to the electrostatic interaction present between the cationic dendrimer and the anionic polyelectrolyte. The DLS results reveal that one salmon sperm DNA molecule forms a discrete aggregate in dilute solution with several PAMAM dendrimers with a mean apparent hydrodynamic radius of 50 nm. These discrete complexes coexist with free DNA at low molar ratios of dendrimer to DNA, which shows that cooperativity is present in the complex formation. The formation of the complexes was confirmed by agarose gel electrophoresis measurements. DNA in the complexes was also found to be significantly more protected against DNase catalyzed digestion compared to free DNA. The number of dendrimers per DNA chain in the complexes was found to be approximately 35 as determined by steady-state fluorescence spectroscopy. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Biomacromolecules
volume
8
issue
5
pages
1557 - 1563
publisher
The American Chemical Society
external identifiers
  • wos:000246413600024
  • scopus:34249881599
ISSN
1526-4602
DOI
10.1021/bm061194z
language
English
LU publication?
yes
id
b5f08fab-8243-4556-9e73-01e1a147dceb (old id 660596)
date added to LUP
2007-12-17 08:42:04
date last changed
2017-07-30 03:42:10
@article{b5f08fab-8243-4556-9e73-01e1a147dceb,
  abstract     = {The interaction between a cationic poly(amido amine) (PAMAM) dendrimer of generation 4 and double-stranded salmon sperm DNA in 10 mM NaBr solution has been investigated using dynamic light scattering (DLS) and steady-state fluorescence spectroscopy. The structural parameters of the formed aggregates as well as the complex formation process were studied in dilute solutions. When DNA is mixed with PAMAM dendrimers, it undergoes a transition from a semiflexible coil to a more compact conformation due to the electrostatic interaction present between the cationic dendrimer and the anionic polyelectrolyte. The DLS results reveal that one salmon sperm DNA molecule forms a discrete aggregate in dilute solution with several PAMAM dendrimers with a mean apparent hydrodynamic radius of 50 nm. These discrete complexes coexist with free DNA at low molar ratios of dendrimer to DNA, which shows that cooperativity is present in the complex formation. The formation of the complexes was confirmed by agarose gel electrophoresis measurements. DNA in the complexes was also found to be significantly more protected against DNase catalyzed digestion compared to free DNA. The number of dendrimers per DNA chain in the complexes was found to be approximately 35 as determined by steady-state fluorescence spectroscopy.},
  author       = {Ainalem, Marie-Louise and Schillén, Karin and Nylander, Tommy},
  issn         = {1526-4602},
  language     = {eng},
  number       = {5},
  pages        = {1557--1563},
  publisher    = {The American Chemical Society},
  series       = {Biomacromolecules},
  title        = {Dynamic light scattering and fluorescence study of the interaction between double-stranded DNA and poly(amido amine) dendrimers},
  url          = {http://dx.doi.org/10.1021/bm061194z},
  volume       = {8},
  year         = {2007},
}