2026-04-14T05:15:57Zhttps://recercat.cat/oai/request
oai:recercat.cat:2445/1770362025-12-05T09:34:50Zcom_2072_1057col_2072_478799col_2072_478917
RECERCAT author Liu, Ge author Molas, Maria author Grossmann, Gregory A. author Pasumarthy, Murali author Perales Losa, Carlos author Cooper, Mark J. author Hanson, Richard W. 2021-05-05T15:16:55Z2021-05-05T15:16:55Z2001-09-142021-05-05T15:16:56Z We have evaluated the effect of NaCl concentration on the mode of binding of poly-L-lysine to DNA and the resulting structural and functional features of the condensed DNA particles using DNA precipitation, DNase I resistance, electron microscopy, and receptor-mediated gene transfer assays. At a high concentration of NaCl and in the presence of excess DNA, poly-L-lysine interacted with DNA cooperatively, fully condensing some of the DNA and leaving the rest of the DNA unbound. At low NaCl concentrations, poly-L-lysine molecules interacted with DNA in a noncooperative fashion, i.e. they bind randomly to the whole population of DNA molecules. Cooperative binding of poly-L-lysine to DNA occurred over a narrow range of NaCl concentrations, and the specific salt concentration depended on the length of the poly-L-lysine. The ability of condensed DNA to withstand digestion by DNase I was correlated with the structural features of the condensed DNA as determined by electron microscopy. Using our condensation procedure, cooperative binding of poly-L-lysine to DNA is a necessary prerequisite for the preparation of condensed DNA having a spherical shape and a diameter of 15-30 nm. Condensed DNA, containing galactosylated poly-L-lysine, was evaluated further for the extent and specificity of receptor-mediated gene transfer into HuH-7 human hepatoma cells via the asialoglycoprotein receptor. Efficient receptor-mediated transfection occurred only when condensed DNA complexes had a spherical shape with a diameter of 15-30 nm; asialofetuin, a natural ligand for the asialoglycoprotein receptor, inhibited this process by up to 90%. Our results support the importance of appropriate DNA condensation for the uptake and ultimate expression of DNA in hepatic cells. (c) American Society for Biochemistry and Molecular Biology, 2001 info:eu-repo/semantics/openAccess ADN Metabolisme Lisina DNA Metabolism Lysine Biological properties of poly-L-lysine/DNA complexes generated by cooperative binding of the polycation info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion