194991-96-3Relevant academic research and scientific papers
A new class of polyintercalating molecules
Lokey, R. Scott,Kwok, Yan,Guelev, Vladimir,Pursell, Christopher J.,Hurley, Laurence H.,Iverson, Brent L.
, p. 7202 - 7210 (1997)
We have synthesized a series of polyintercalating compounds, including the first known tetraintercalator, based on the 1,4,5,8-naphthalenetetracarboxylic diimide chromophore. The chromophores are attached in a head-to-tail arrangement by peptide linkers and are synthesized by standard solid phase peptide synthesis methods. We report evidence, based on UV-visible spectroscopy and viscometry, that the compounds are fully intercalated upon binding to double-stranded DNA. Using DNAse I footprinting experiments, the bisintercalator 2 was found to bind to DNA in a cooperative manner. The footprinting results as well as association and dissociation kinetics data reveal that the compounds exhibit a tremendous preference for GC over AT sequences. A mode of binding is proposed in which the compounds intercalate completely from the major groove, and not in a threading manner as may be suggested by their structures. A kinetic scheme is proposed that takes into account the observed cooperativity and fits the data for the dissociations of the polyintercalators from poly(dAdT), although a similar scheme could not adequately model their dissociations from poly(dGdC) or from calf thymus DNA.
An Octakis-intercalating molecule
Murr, Meredith M.,Harting, Matthew T.,Guelev, Vladimir,Ren, Jinsong,Chaires, Jonathan B.,Iverson, Brent L.
, p. 1141 - 1148 (2001)
Herein we report the synthesis and characterization of a polyintercalator with eight potential intercalating 1,4,5,8-naphthalenetetracarboxylic diimide (NDI) units linked in a head-to-tail arrangement via a peptide linker. UV spectroscopy and viscometry measurements indicated the molecule binds to double-stranded DNA with all eight NDI units intercalated simultaneously. Competition dialysis and DNAse 1 footprinting studies revealed a preference for GC-rich regions of DNA, and circular dichroism studies revealed significant distortion of B-form DNA upon binding. Our so-called 'octamer' represents, to the best of our knowledge, the first intercalator that binds as an octakis-intercalator, capable of spanning at least 16 base pairs of DNA.
The synthesis and screening of 1,4,5,8-naphthalenetetracarboxylic diimide-peptide conjugates with antibacterial activity
Miller, Chandra T.,Weragoda, Ramal,Izbicka, Elzbieta,Iverson, Brent L.
, p. 2015 - 2024 (2001)
We have employed an initial combinatorial approach followed by systematic lead optimization to investigate a series of novel molecules that exhibit antimicrobial activity against Gram-negative and Gram-positive bacteria. The new molecules contain various sequences of amino acids, generally L-lysine and glycine, attached to the 1,4,5,8-naphthalenetetracarboxylic diimide aromatic unit. Systematic structure-activity studies found that increasing positive charge enhanced activity and molecules containing one naphthalenetetracarboxylic diimide unit as well as at least seven lysine residues were optimum for antimicrobial activity. The naphthalenetetracarboxylic diimide derivatives were found to be inactive against mammalian cell lines, making them excellent antimicrobial candidates. Our results indicate that combining positive charge with aromatic and/or hydrophobic elements may be an interesting new approach to antimicrobial agents and adds an important new dimension to the field of cationic peptides.
Synthesis and conformational characterization of tethered, self-complexing 1,5-dialkoxynaphthalene/1,4,5,8-naphthalenetetracarboxylic diimide systems
Zych, Andrew J.,Iverson, Brent L.
, p. 8898 - 8909 (2007/10/03)
Chemists are beginning to explore the abiotic folding of synthetic chains, and the term "foldamers" has been used to characterize oligomers with a strong inclination to adopt specific, compact conformations. The characterization of folded structure in solution is one of the difficult challenges facing the foldamer field. Aedamers were the first foldamers to make use of aromatic-aromatic interactions in water to direct folding and were designed to have several spectroscopic handles with which to probe folding conformations in solution. Herein is reported the synthesis and spectroscopic characterization of eleven aedamer dimers, with linkers chosen to provide a spectrum of lengths and flexibilities. The dimers, composed of one electron rich (1,5-dialkoxynaphthalene) and one electron deficient (1,4,5,8-naphthalenetetracarboxylic diimide) aromatic group tethered by a linker, are the smallest aedamer folding unit. The powerful spectroscopic handles associated with the stacked aedamer groups were exploited in a comprehensive spectroscopic analysis of conformation that included UV-vis absorption spectroscopy, fluorescence measurements (including time-resolved studies), as well as detailed NMR studies. The spectra were interpreted in the context of molecular modeling/spectral prediction and structural models were developed for the different dimers in aqueous solution. In most instances, the observed data was best described by an ensemble of predicted structures as opposed to one or few conformers. Thus, in the case of these aedamer dimers, "folding" does not appear to imply a two-state model with a rigid, unique conformation. Rather, the reported analysis indicates the data can best be described by a more dynamic model in which a given molecule spends its time in different folded conformations that are related by having a characteristic face-to-face stacking arrangement of the aromatic units.
