A nanobiosensor for the simple detection of small molecules using non-crosslinking aggregation of gold nanoparticles with G-quadruplexes

2020 ◽  
Vol 12 (3) ◽  
pp. 230-238
Author(s):  
Surachada Chuaychob ◽  
Chongdee Thammakhet-Buranachai ◽  
Proespichaya Kanatharana ◽  
Panote Thavarungkul ◽  
Chittanon Buranachai ◽  
...  

This work demonstrates a simple and specific colorimetric sensor for a hazardous small molecule, cisplatin, using a G-quadruplex (G4) DNA as a sensing probe and non-crosslinking aggregation of gold nanoparticles (AuNPs) as a signal enhancer.

Molecules ◽  
2019 ◽  
Vol 24 (8) ◽  
pp. 1578 ◽  
Author(s):  
Guanhui Wu ◽  
Luying Chen ◽  
Wenting Liu ◽  
Danzhou Yang

G-quadruplex (G4) DNA secondary structures formed in human telomeres have been shown to inhibit cancer-specific telomerase and alternative lengthening of telomere (ALT) pathways. Thus, human telomeric G-quadruplexes are considered attractive targets for anticancer drugs. Human telomeric G-quadruplexes are structurally polymorphic and predominantly form two hybrid-type G-quadruplexes, namely hybrid-1 and hybrid-2, under physiologically relevant solution conditions. To date, only a handful solution structures are available for drug complexes of human telomeric G-quadruplexes. In this review, we will describe two recent solution structural studies from our labs. We use NMR spectroscopy to elucidate the solution structure of a 1:1 complex between a small molecule epiberberine and the hybrid-2 telomeric G-quadruplex, and the structures of 1:1 and 4:2 complexes between a small molecule Pt-tripod and the hybrid-1 telomeric G-quadruplex. Structural information of small molecule complexes can provide important information for understanding small molecule recognition of human telomeric G-quadruplexes and for structure-based rational drug design targeting human telomeric G-quadruplexes.


2015 ◽  
Vol 1088 ◽  
pp. 507-513
Author(s):  
Hui Yu ◽  
Yan Li Wang ◽  
Xiao Yin Zhao ◽  
Wen Zhang

G-quadruplex is expected to be a promising target for drug design. The manually synthesized small-molecule compounds are able to induce the formation of and stabilize G-quadruplexes. In this paper, we summarize the current understanding of the structure of G-quadruplexes, the binding mode of G-quadruplexes and small-molecule ligands, and important synthesized small molecules targeting G-quadruplexes as potential drugs.


2014 ◽  
Vol 6 (19) ◽  
pp. 8018-8021 ◽  
Author(s):  
Zhengbo Chen ◽  
Junxia Guo ◽  
He Ma ◽  
Tong Zhou ◽  
Xiaoxiao Li

A simple colorimetric sensor for potassium ion detection.


2020 ◽  
Author(s):  
Jérémie Mitteaux ◽  
Pauline Lejault ◽  
Marc Pirrotta ◽  
Filip Wojciechowski ◽  
Alexandra Joubert ◽  
...  

AbstractThe quest for small molecules that avidly bind to G-quadruplex-DNA (G4-DNA, or G4), so called G4-ligands, has invigorated the G4 research field from its very inception. Massive efforts have been invested to i- screen or design G4-ligands, ii- evaluate their G4-interacting properties in vitro through a series of now widely accepted and routinely implemented assays, and iii- use them as unique chemical biology tools to interrogate cellular networks that might involve G4s. In sharp contrast, only uncoordinated efforts at developing small molecules aimed at destabilizing G4s have been invested to date, even though it is now recognized that such molecular tools would have tremendous application to neurobiology as many genetic and age-related diseases are caused by an over-representation of G4s, itself caused by a deficiency of G4-resolving enzymes, the G4-helicases. Herein, we report on our double effort to i- develop a reliable in vitro assay to identify molecules able to destabilize G4s, the G4-unfold assay, and ii- fully characterize the first prototype of G4-disrupting small molecule, a phenylpyrrolcytosine (PhpC)-based G-clamp analog.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii200-ii200
Author(s):  
Stephen Skirboll ◽  
Natasha Lucki ◽  
Genaro Villa ◽  
Naja Vergani ◽  
Michael Bollong ◽  
...  

Abstract INTRODUCTION Glioblastoma multiforme (GBM) is the most aggressive form of primary brain cancer. A subpopulation of multipotent cells termed GBM cancer stem cells (CSCs) play a critical role in tumor initiation and maintenance, drug resistance, and recurrence following surgery. New therapeutic strategies for the treatment of GBM have recently focused on targeting CSCs. Here we have used an unbiased large-scale screening approach to identify drug-like small molecules that induce apoptosis in GBM CSCs in a cell type-selective manner. METHODS A luciferase-based survival assay of patient-derived GBM CSC lines was established to perform a large-scale screen of ∼one million drug-like small molecules with the goal of identifying novel compounds that are selectively toxic to chemoresistant GBM CSCs. Compounds found to kill GBM CSC lines as compared to control cell types were further characterized. A caspase activation assay was used to evaluate the mechanism of induced cell death. A xenograft animal model using patient-derived GBM CSCs was employed to test the leading candidate for suppression of in vivo tumor formation. RESULTS We identified a small molecule, termed RIPGBM, from the cell-based chemical screen that induces apoptosis in primary patient-derived GBM CSC cultures. The cell type-dependent selectivity of RIPGBM appears to arise at least in part from redox-dependent formation of a proapoptotic derivative, termed cRIPGBM, in GBM CSCs. cRIPGBM induces caspase 1-dependent apoptosis by binding to receptor-interacting protein kinase 2 (RIPK2) and acting as a molecular switch, which reduces the formation of a prosurvival RIPK2/TAK1 complex and increases the formation of a proapoptotic RIPK2/caspase 1 complex. In an intracranial GBM xenograft mouse model, RIPGBM was found to significantly suppress tumor formation. CONCLUSIONS Our chemical genetics-based approach has identified a small molecule drug candidate and a potential drug target that selectively targets cancer stem cells and provides an approach for the treatment of GBMs.


2021 ◽  
Author(s):  
Jun Gao ◽  
Zhaofeng Gao ◽  
Andrea A. Putnam ◽  
Alicia K. Byrd ◽  
Sarah L. Venus ◽  
...  

G-quadruplex (G4) DNA inhibits RNA unwinding activity but promotes liquid–liquid phase separation of the DEAD-box helicase Ded1p in vitro and in cells. This highlights multifaceted effects of G4DNA on an enzyme with intrinsically disordered domains.


2021 ◽  
Author(s):  
Amit Ketkar ◽  
Lane Smith ◽  
Callie Johnson ◽  
Alyssa Richey ◽  
Makayla Berry ◽  
...  

Abstract We previously reported that human Rev1 (hRev1) bound to a parallel-stranded G-quadruplex (G4) from the c-MYC promoter with high affinity. We have extended those results to include other G4 motifs, finding that hRev1 exhibited stronger affinity for parallel-stranded G4 than either anti-parallel or hybrid folds. Amino acids in the αE helix of insert-2 were identified as being important for G4 binding. Mutating E466 and Y470 to alanine selectively perturbed G4 binding affinity. The E466K mutant restored wild-type G4 binding properties. Using a forward mutagenesis assay, we discovered that loss of hRev1 increased G4 mutation frequency >200-fold compared to the control sequence. Base substitutions and deletions occurred around and within the G4 motif. Pyridostatin (PDS) exacerbated this effect, as the mutation frequency increased >700-fold over control and deletions upstream of the G4 site more than doubled. Mutagenic replication of G4 DNA (±PDS) was partially rescued by wild-type and E466K hRev1. The E466A or Y470A mutants failed to suppress the PDS-induced increase in G4 mutation frequency. These findings have implications for the role of insert-2, a motif conserved in vertebrates but not yeast or plants, in Rev1-mediated suppression of mutagenesis during G4 replication.


Sign in / Sign up

Export Citation Format

Share Document