Conformationally restricted cationic polyamide analogs of nucleic acids: Design, synthesis, and DNA/RNA binding studies

2004 ◽  
Vol 76 (7-8) ◽  
pp. 1599-1603 ◽  
Author(s):  
V. A. Kumar ◽  
Moneesha D'Costa ◽  
P. S. Lonkar ◽  
P. S. Pallan ◽  
K. N. Ganesh ◽  
...  

The remarkable medicinal importance of the achiral, acyclic, and uncharged aminoethylglycyl peptide nucleic acids (aegPNAs) as DNA/RNA mimics has challenged chemists to circumvent the limitations of their in vivo efficacy. In this context, we have designed conformationally restricted five- and six-membered cyclic PNA analogs by introduction of chemical bridges in aegPNAs leading to a large variety of structures with defined configurations and conformational preferences, effecting concomitant installation of a positive charge in the backbone. The synthesis and biophysical properties of these cationic aminoethylprolyl PNAs, pyrrolidine PNAs, and piperidine PNAs endowed with increased water solubility and affinity toward target nucleic acids is presented. These nucleic acid analogs as lead structures are a part of a chemical evolution process that might give rise to a synthetic nucleic acid analog having optimum properties for medicinal applications.

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2196 ◽  
Author(s):  
Silvana Alfei ◽  
Anna Maria Schito ◽  
Guendalina Zuccari

Ursolic acid (UA) is a pentacyclic triterpenoid found in many medicinal plants and aromas endowed with numerous in vitro pharmacological activities, including antibacterial effects. Unfortunately, UA is poorly administered in vivo, due to its water insolubility, low bioavailability, and residual systemic toxicity, thus making urgent the development of water-soluble UA formulations. Dendrimers are nonpareil macromolecules possessing highly controlled size, shape, and architecture. In dendrimers with cationic surface, the contemporary presence of inner cavities and of hydrophilic peripheral functions, allows to encapsulate hydrophobic non-water-soluble drugs as UA, to enhance their water-solubility and stability, and to promote their protracted release, thus decreasing their systemic toxicity. In this paper, aiming at developing a new UA-based antibacterial agent administrable in vivo, we reported the physical entrapment of UA in a biodegradable not cytotoxic cationic dendrimer (G4K). UA-loaded dendrimer nanoparticles (UA-G4K) were obtained, which showed a drug loading (DL%) much higher than those previously reported, a protracted release profile governed by diffusion mechanisms, and no cytotoxicity. Also, UA-G4K was characterized by principal components analysis (PCA)-processed FTIR spectroscopy, by NMR and elemental analyses, and by dynamic light scattering experiments (DLS). The water solubility of UA-G4K was found to be 1868-fold times higher than that of pristine UA, thus making its clinical application feasible.


1993 ◽  
Vol 13 (5) ◽  
pp. 2730-2741 ◽  
Author(s):  
J T Anderson ◽  
S M Wilson ◽  
K V Datar ◽  
M S Swanson

A variety of nuclear ribonucleoproteins are believed to associate directly with nascent RNA polymerase II transcripts and remain associated during subsequent nuclear RNA processing reactions, including pre-mRNA polyadenylation and splicing as well as nucleocytoplasmic mRNA transport. To investigate the functions of these proteins by using a combined biochemical and genetic approach, we have isolated nuclear polyadenylated RNA-binding (NAB) proteins from Saccharomyces cerevisiae. Living yeast cells were irradiated with UV light to covalently cross-link proteins intimately associated with RNA in vivo. Polyadenylated RNAs were then selectively purified, and the covalent RNA-protein complexes were used to elicit antibodies in mice. Both monoclonal and polyclonal antibodies which detect a variety of NAB proteins were prepared. Here we characterize one of these proteins, NAB2. NAB2 is one of the major proteins associated with nuclear polyadenylated RNA in vivo, as detected by UV light-induced cross-linking. Cellular immunofluorescence, using both monoclonal and polyclonal antibodies, demonstrates that the NAB2 protein is localized within the nucleus. The deduced primary structure of NAB2 indicates that it is composed of at least two distinct types of RNA-binding motifs: (i) an RGG box recently described in a variety of heterogeneous nuclear RNA-, pre-rRNA-, mRNA-, and small nucleolar RNA-binding proteins and (ii) CCCH motif repeats related to the zinc-binding motifs of the largest subunit of RNA polymerases I, II, and III. In vitro RNA homopolymer/single-stranded DNA binding studies indicate that although both the RGG box and CCCH motifs bind poly(G), poly(U), and single-stranded DNA, the CCCH motifs also bind to poly(A). NAB2 is located on chromosome VII within a cluster of ribonucleoprotein genes, and its expression is essential for cell growth.


2018 ◽  
Vol 6 (44) ◽  
pp. 7197-7203 ◽  
Author(s):  
Cory D. Sago ◽  
Sujay Kalathoor ◽  
Jordan P. Fitzgerald ◽  
Gwyneth N. Lando ◽  
Naima Djeddar ◽  
...  

The efficacy of nucleic acid therapies can be limited by unwanted degradation.


Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4659 ◽  
Author(s):  
Steven Ochoa ◽  
Valeria T. Milam

In the last three decades, oligonucleotides have been extensively investigated as probes, molecular ligands and even catalysts within therapeutic and diagnostic applications. The narrow chemical repertoire of natural nucleic acids, however, imposes restrictions on the functional scope of oligonucleotides. Initial efforts to overcome this deficiency in chemical diversity included conservative modifications to the sugar-phosphate backbone or the pendant base groups and resulted in enhanced in vivo performance. More importantly, later work involving other modifications led to the realization of new functional characteristics beyond initial intended therapeutic and diagnostic prospects. These results have inspired the exploration of increasingly exotic chemistries highly divergent from the canonical nucleic acid chemical structure that possess unnatural physiochemical properties. In this review, the authors highlight recent developments in modified oligonucleotides and the thrust towards designing novel nucleic acid-based ligands and catalysts with specifically engineered functions inaccessible to natural oligonucleotides.


1984 ◽  
Vol 17 (1) ◽  
pp. 1-44 ◽  
Author(s):  
John E. Hearst ◽  
Stephen T. Isaacs ◽  
David Kanne ◽  
Henry Rapoport ◽  
Kenneth Straub

Psoralen photochemistry is specific for nucleic acids and is better understood at the molecular level than are all other methods of chemical modification of nucleic acids. These compounds are used both for in vivo structure analysis and for photochemotherapy since they easily penetrate both cells and virus particles. Apparently, natural selection has selected for membrane and virus penetrability during the evolution of these natural products. Most cells are unaffected by relatively high concentrations of psoralens in the absence of ultraviolet light, and the metabolites of the psoralens have thus far not created a problem. Finally, psoralens form both monoadduct and cross-links in nucleic acid helices, the yield of each being easily controlled by the conditions used during the photochemistry.


2006 ◽  
Vol 71 (7) ◽  
pp. 929-955 ◽  
Author(s):  
Vladimir A. Efimov ◽  
Oksana G. Chakhmakhcheva

With the aim to improve physicochemical and biological properties of natural oligonucleotides, many types of DNA analogues and mimics are designed on the basis of hydroxyproline and its derivatives, and their properties are evaluated. Among them, two types of DNA mimics representing hetero-oligomers constructed from alternating monomers of phosphono peptide nucleic acids and monomers on the base of trans-1-acetyl-4-hydroxy-L-proline (HypNA-pPNAs) and oligomers constructed from monomers containing (2S,4R)-1-acetyl-4-hydroxypyrrolidine-2-phosphonic acid backbone (pHypNAs) are of particular interest. In a set of in vitro and in vivo assays, it was shown that HypNA-pPNAs and pHypNAs demonstrated a high potential for the use in nucleic acid based diagnostics, isolation of nucleic acids and antisense experiments. A review with 53 references.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3471-3471
Author(s):  
Jennifer Whangbo ◽  
Marshall Thomas ◽  
Geoffrey McCrossan ◽  
Aaron Deutsch ◽  
Kimberly Martinod ◽  
...  

Abstract When released from cytotoxic T lymphocytes and natural killer cells, Granzyme (Gzm) serine proteases induce programmed cell death of pathogen-infected cells and tumor cells. The Gzms rapidly accumulate in the target cell nucleus by an unknown mechanism. Many of the known substrates of GzmA and GzmB, the most abundant killer cell proteases, bind to DNA or RNA. Gzm substrates predicted by unbiased proteomics studies are also highly enriched for nucleic acid binding proteins. Here we show by fluorescence polarization assays that Gzms bind DNA and RNA with nanomolar affinity. We hypothesized that Gzm binding to nucleic acids enhances nuclear accumulation in target cells and facilitates their cleavage of nucleic acid-binding substrates. In fact, RNase treatment of cell lysates reduced cleavage of RNA binding protein (RBP) targets by GzmA and GzmB. Moreover, adding RNA to recombinant RBP substrates greatly enhanced in vitro cleavage by GzmB, but adding RNA to non-nucleic acid binding proteins did not. For example, exogenous RNA enhanced GzmB cleavage of recombinant hnRNP C1 (an RBP) but not LMNB1 (a non-RBP). In addition, GzmB cleaved the RNA-binding HuR protein efficiently only when it was bound to an HuR-binding RNA oligonucleotide, but not in the presence of an equal amount of non-binding RNA. Thus, nucleic acids facilitate Gzm cleavage of nucleic acid binding substrates. To evaluate whether nucleic acid binding influences Gzm trafficking in target cells, we incubated fixed target cells with RNase and then added Gzms. RNA degradation in target cells reduced Gzm cytosolic localization and increased nuclear accumulation. Similarly, pre-incubating Gzms with exogenous competitor DNA reduced Gzm nuclear localization. The Gzms form a monophyletic clade with other immune serine proteases including neutrophil elastase (NE) and cathepsin G (CATG). Upon neutrophil activation, NE translocates to the nucleus to drive the formation of neutrophil extracellular traps (NETs). NE and CATG, but not non-immune serine proteases such as trypsin and pancreatic elastase, also bind DNA with high affinity and localize to the nucleus of permeabilized cells. Consistent with this finding, competitor DNA also blocks the nuclear localization of NE. Moreover NE and CATG localization to NETs depends on DNA binding. Thus the antimicrobial activity of NETs may depend in part upon the affinity of these proteases for DNA. Our findings indicate that high affinity nucleic acid binding is a conserved and functionally important property of serine proteases involved in cell-mediated immunity. Disclosures: Lieberman: Alnylam Pharmaceuticals: Membership on an entity’s Board of Directors or advisory committees.


2018 ◽  
Vol 14 ◽  
pp. 114-129 ◽  
Author(s):  
Mattias Bood ◽  
Sangamesh Sarangamath ◽  
Moa S Wranne ◽  
Morten Grøtli ◽  
L Marcus Wilhelmsson

Förster resonance energy transfer (FRET) between a donor nucleobase analogue and an acceptor nucleobase analogue, base–base FRET, works as a spectroscopic ruler and protractor. With their firm stacking and ability to replace the natural nucleic acid bases inside the base-stack, base analogue donor and acceptor molecules complement external fluorophores like the Cy-, Alexa- and ATTO-dyes and enable detailed investigations of structure and dynamics of nucleic acid containing systems. The first base–base FRET pair, tCO–tCnitro, has recently been complemented with among others the adenine analogue FRET pair, qAN1–qAnitro, increasing the flexibility of the methodology. Here we present the design, synthesis, photophysical characterization and use of such base analogues. They enable a higher control of the FRET orientation factor, κ 2, have a different distance window of opportunity than external fluorophores, and, thus, have the potential to facilitate better structure resolution. Netropsin DNA binding and the B-to-Z-DNA transition are examples of structure investigations that recently have been performed using base–base FRET and that are described here. Base–base FRET has been around for less than a decade, only in 2017 expanded beyond one FRET pair, and represents a highly promising structure and dynamics methodology for the field of nucleic acids. Here we bring up its advantages as well as disadvantages and touch upon potential future applications.


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