title: Assessment of RNA carrier function in peptide amphiphiles derived from the HIV fusion peptide.
abstract: A small library of amphiphilic peptides has been evaluated for duplex RNA carrier function into A549 cells. We studied peptides in which a C-terminal 7-residue cationic domain is attached to a neutral/hydrophobic 23-residue domain that is based on the viral fusion peptide of HIV. We also examined peptides in which the cationic charge was evenly distributed throughout the peptide. Strikingly, subtle sequence variations in the hydrophobic domain that do not alter net hydrophobicity result in wide variation in RNA uptake. Additionally, cyclic cystine variants are much less active as RNA carriers than their open-chain cysteine analogs. With regard to electrostatic effects, we find that lysine is less effective than arginine in facilitating uptake, and that even distribution of cationic residues throughout the peptide sequence results in especially effective RNA carrier function. Overall, minor changes in peptide hydrophobicity, flexibility and charge distribution can significantly alter carrier function. We hypothesize this is due to altered properties of the peptide-RNA assembly rather than peptide secondary structure.
authors.affiliation: Department of Chemistry and Biochemistry, The Ohio State University, 100 W. 18th Avenue, Columbus, OH 43210, United States.
authors.forename: Yaowalak
authors.initials: Y
authors.lastname: Pratumyot
authors.affiliation: Department of Chemistry and Biochemistry, The Ohio State University, 100 W. 18th Avenue, Columbus, OH 43210, United States.
authors.forename: Oscar B
authors.initials: OB
authors.lastname: Torres
authors.affiliation: Department of Chemistry and Biochemistry, The Ohio State University, 100 W. 18th Avenue, Columbus, OH 43210, United States. Electronic address: bong.6@osu.edu.
authors.forename: Dennis
authors.initials: D
authors.lastname: Bong
mesh_terms: D000072283:A549 Cells; D015700:HIV Envelope Protein gp41 / Q000737:chemistry; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D010455:Peptides / Q000737:chemistry*; D012313:RNA / Q000235:genetics; D014162:Transfection
chemical_list: D015700:HIV Envelope Protein gp41; D010455:Peptides; C514787:gp41 protein, Human immunodeficiency virus 1; D012313:RNA
keywords: Amphiphilic peptide; Carrier; Electrostatics; Nucleic acids; Transport