title: Differences in DNA condensation and release by lysine and arginine homopeptides govern their DNA delivery efficiencies.
abstract: Designing of nanocarriers that can efficiently deliver therapeutic DNA payload and allow its smooth intracellular release for transgene expression is still a major constraint. The optimization of DNA nanocarriers requires thorough understanding of the chemical and structural characteristics of the vector-nucleic acid complexes and its correlation with the cellular entry, intracellular state and transfection efficiency. L-lysine and L-arginine based cationic peptides alone or in conjugation with other vectors are known to be putative DNA delivery agents. Here we have used L-lysine and L-arginine homopeptides of three different lengths and probed their DNA condensation and release properties by using a multitude of biophysical techniques including fluorescence spectroscopy, gel electrophoresis and atomic force microscopy. Our results clearly showed that although both lysine and arginine based homopeptides condense DNA via electrostatic interactions, they follow different pattern of DNA condensation and release in vitro. While lysine homopeptides condense DNA to form both monomolecular and multimolecular complexes and show differential release of DNA in vitro depending on the peptide length, arginine homopeptides predominantly form multimolecular complexes and show complete DNA release for all peptide lengths. The cellular uptake of the complexes and their intracellular state (as observed through flow cytometry and fluorescence microscopy) seem to be controlled by the peptide chemistry. The difference in the transfection efficiency of lysine and arginine homopeptides has been rationalized in light of these observations.
authors.affiliation: Institute of Genomics and Integrative Biology, CSIR, Mall Road, Delhi 110007, India.
authors.forename: Anita
authors.initials: A
authors.lastname: Mann
authors.forename: Garima
authors.initials: G
authors.lastname: Thakur
authors.forename: Vasundhara
authors.initials: V
authors.lastname: Shukla
authors.forename: Anand Kamal
authors.initials: AK
authors.lastname: Singh
authors.forename: Richa
authors.initials: R
authors.lastname: Khanduri
authors.forename: Rangeetha
authors.initials: R
authors.lastname: Naik
authors.forename: Yang
authors.initials: Y
authors.lastname: Jiang
authors.forename: Namita
authors.initials: N
authors.lastname: Kalra
authors.forename: B S
authors.initials: BS
authors.lastname: Dwarakanath
authors.forename: Ulo
authors.initials: U
authors.lastname: Langel
authors.forename: Munia
authors.initials: M
authors.lastname: Ganguli
mesh_terms: D000818:Animals; D001120:Arginine / Q000737:chemistry* / Q000378:metabolism; D001692:Biological Transport; D016466:CHO Cells; D045744:Cell Line, Tumor; D006224:Cricetinae; D003412:Cricetulus; D042003:DNA Packaging; D004273:DNA, Neoplasm / Q000737:chemistry / Q000648:ultrastructure*; D004279:DNA, Viral / Q000008:administration & dosage / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000737:chemistry; D018014:Gene Transfer Techniques; D005822:Genetic Vectors / Q000378:metabolism; D006801:Humans; D008239:Lysine / Q000737:chemistry* / Q000378:metabolism; D008970:Molecular Weight; D009369:Neoplasms / Q000378:metabolism / Q000648:ultrastructure*; D009690:Nucleic Acid Conformation; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism; D010316:Particle Size; D010455:Peptides / Q000737:chemistry* / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D004273:DNA, Neoplasm; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D009842:Oligopeptides; D010455:Peptides; D001120:Arginine; D008239:Lysine