polymers. On the other hand, the way Nature deals with the complexation of genetic
material by proteins is extremely efficient: the genome of eukaryotic cells is
packaged in a topologically controlled manner in the form of fibrous superstructures
known as chromatin, and this allows DNA with a contour length of 2 m to be
packaged in the nucleus of cells only a few micrometers in diameter [39]. The
nucleosome core particle (NCP) is the fundamental building block of chromatin
Scheme 2 Various topologies of dsDNA molecule: linear, circular, and supercoiled
Scheme 3 Schematic view of some levels of DNA folding in the cell. (a) On length scales much
smaller than the persistence length ( p b ), DNA can be considered straight. (b) In eukaryotic cells,
DNA wraps around a core of histone proteins to create a nucleosome structure. (c) Structure
of chromation with “beads-on-a-string” configuration. Reprinted with permission from [243].
Copyright 2012 American Society for Biochemistry and Molecular Biology
Polyelectrolyte Complexes of DNA and Polycations as Gene Delivery Vectors
109
material by proteins is extremely efficient: the genome of eukaryotic cells is
packaged in a topologically controlled manner in the form of fibrous superstructures
known as chromatin, and this allows DNA with a contour length of 2 m to be
packaged in the nucleus of cells only a few micrometers in diameter [39]. The
nucleosome core particle (NCP) is the fundamental building block of chromatin
Scheme 2 Various topologies of dsDNA molecule: linear, circular, and supercoiled
Scheme 3 Schematic view of some levels of DNA folding in the cell. (a) On length scales much
smaller than the persistence length ( p b ), DNA can be considered straight. (b) In eukaryotic cells,
DNA wraps around a core of histone proteins to create a nucleosome structure. (c) Structure
of chromation with “beads-on-a-string” configuration. Reprinted with permission from [243].
Copyright 2012 American Society for Biochemistry and Molecular Biology
Polyelectrolyte Complexes of DNA and Polycations as Gene Delivery Vectors
109