title: Apo B100 similarities to viral proteins suggest basis for LDL-DNA binding and transfection capacity.
abstract: LDL mediates transfection with plasmid DNA in a variety of cell types in vitro and in several tissues in vivo in the rat. The transfection capacity of LDL is based on apo B100, as arginine/lysine clusters, suggestive of nucleic acid-binding domains and nuclear localization signal sequences, are present throughout the molecule. Apo E may also contribute to this capacity because of its similarity to the Dengue virus capsid proteins and its ability to bind DNA. Synthetic peptides representing two apo B100 regions with prominent Arg/Lys clusters were shown to bind DNA. Region 1 (0014Lys-Ser0160) shares sequence motifs present in DNA binding domains of Interferon Regulatory Factors and Flaviviridae capsid/core proteins. It also contains a close analog of the B/E receptor ligand of apo E. Region 1 peptides, B1-1 (0014Lys-Glu0054) and B1-2 (0055Leu-Ala0096), mediate transfection of HeLa cells but are cytotoxic. Region 2 (3313Asp-Thr3431), containing the known B/E receptor ligand, shares analog motifs with the human herpesvirus 5 immediate-early transcriptional regulator (UL122) and Flaviviridae NS3 helicases. Region 2 peptides, B2-1 (3313Asp-Glu3355), and B2-2 (3356Gly-Thr3431) are ineffective in cell transfection and are noncytotoxic. These results confirm the role of LDL as a natural transfection vector in vivo, a capacity imparted by the apo B100, and suggest a basis for Flaviviridae cell entry.
authors.affiliation: Department of Physics and Astronomy, University of Texas Brownsville/Texas Southmost College, Brownsville, TX 78520, USA.
authors.forename: Juan
authors.initials: J
authors.lastname: Guevara
authors.forename: Nagindra
authors.initials: N
authors.lastname: Prashad
authors.forename: Boris
authors.initials: B
authors.lastname: Ermolinsky
authors.forename: John W
authors.initials: JW
authors.lastname: Gaubatz
authors.forename: Dongcheul
authors.initials: D
authors.lastname: Kang
authors.forename: Andrea E
authors.initials: AE
authors.lastname: Schwarzbach
authors.forename: David S
authors.initials: DS
authors.lastname: Loose
authors.forename: Natalia Valentinova
authors.initials: NV
authors.lastname: Guevara
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D053299:Apolipoprotein B-100 / Q000235:genetics / Q000378:metabolism; D001057:Apolipoproteins E / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D005260:Female; D018067:Flaviviridae / Q000235:genetics / Q000378:metabolism; D017930:Genes, Reporter; D006801:Humans; D008077:Lipoproteins, LDL / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014018:Tissue Distribution; D014162:Transfection / Q000379:methods*; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D053299:Apolipoprotein B-100; D001057:Apolipoproteins E; D008077:Lipoproteins, LDL; D010455:Peptides; D014764:Viral Proteins; D004247:DNA