Independent versus cooperative binding in polyethylenimine-DNA and Poly(L-lysine)-DNA polyplexes.
The mechanism of polyethylenimine-DNA and poly(L-lysine)-DNA complex formation at pH 5.2 and 7.4 was studied by a time-resolved spectroscopic method. The formation of a polyplex core was observed to be complete at approximately N/P = 2, at which point nearly all DNA phosphate groups were bound by polymer amine groups. The data were analyzed further both by an independent binding model and by a cooperative model for multivalent ligand binding to multisubunit substrate. At pH 5.2, the polyplex formation was cooperative at all N/P ratios, whereas for pH 7.4 at N/P < 0.6 the polyplex formation followed independent binding changing to cooperative binding at higher N/Ps.
Department of Chemistry and Bioengineering, Tampere University of Technology , Korkeakoulunkatu 10, 33720 Tampere, Finland.
Tiia-Maaria
TM
Ketola
Martina
M
Hanzlíková
Linda
L
Leppänen
Manuela
M
Raviña
Corey J
CJ
Bishop
Jordan J
JJ
Green
Arto
A
Urtti
Helge
H
Lemmetyinen
Marjo
M
Yliperttula
Elina
E
Vuorimaa-Laukkanen
D000818:Animals; D016466:CHO Cells; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010316:Particle Size; D011094:Polyethyleneimine / Q000737:chemistry*; D011107:Polylysine / Q000737:chemistry*
D011107:Polylysine; D011094:Polyethyleneimine; D004247:DNA