title: Modification of plasmid DNA topology by 'histone-mimetic' gold nanoparticles.
abstract: OBJECTIVE
  Our aim is to explore whether gold nanoparticles (AuNPs) functionalized with a carboxylated polyethylene glycol (PEG) and protamine (AuNP@PEG@Prot) can modulate - enhance or restrain - DNA condensation, altering DNA conformation and inducing structural changes. Understanding how these nanoconjugates modulate DNA structure, size and shape of DNA condensates, and enable control over the resulting 3D structures is of major biological and therapeutic importance.
  
  
  METHODS
  Citrate-AuNPs were covered with a dense layer of a hetero-functional octa(ethylene glycol) (SH-EG(8)-COOH). Conjugation of protamine to the AuNP@PEG was achieved by taking advantage of the carboxylated surface previously generated on the surface of the NP and the remaining amino groups from the protamine, using carbodiimide and N-hydroxysulfosuccinimide coupling reactions.
  
  
  CONCLUSIONS
  AuNP@PEG@Prot modulates the structure and topology of DNA, not only for condensation, but also for decondensation, via formation of higher quantities of dimers and multimers, when compared with AuNP@PEG and free protamine.
authors.affiliation: Instituto de Nanociencia de Aragón, Universidad de Zaragoza, Mariano Esquillor s/n 50018, Zaragoza, Spain.
authors.forename: João
authors.initials: J
authors.lastname: Conde
authors.forename: Pedro V
authors.initials: PV
authors.lastname: Baptista
authors.forename: Yulan
authors.initials: Y
authors.lastname: Hernández
authors.forename: Vanesa
authors.initials: V
authors.lastname: Sanz
authors.forename: Jesus M
authors.initials: JM
authors.lastname: de la Fuente
mesh_terms: D000818:Animals; D040761:Biomimetic Materials / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D019281:Dimerization; D006046:Gold / Q000737:chemistry*; D006657:Histones / Q000737:chemistry; D058726:Nanoconjugates / Q000737:chemistry* / Q000648:ultrastructure; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011479:Protamines / Q000737:chemistry*; D012474:Salmon
chemical_list: D006657:Histones; D058726:Nanoconjugates; D011479:Protamines; D011092:Polyethylene Glycols; D006046:Gold; D004247:DNA