Applications of guanine quartets in nanotechnology and chemical biology

The noncovalent dimerization of a G-quadruplex/hemin DNAzyme improves its biocatalytic properties

“…[13][14][15][16][17][18][19][20][21] An interesting tertiary structure is the G-quadruplex (GQ) that folds from guanine-rich sequences through the stacking of G-quartets, i.e., arrays of four guanines associated via Hoogsteen hydrogen bonds. [22][23][24][25][26] A GQ exhibits enticing catalytic properties notably upon interaction with hemin (Fe(III)-protoporphyrin IX), a well-known cofactor of hemoproteins. 27,28 The stacking of hemin onto an accessible Gquartet of a GQ provides a catalytic GQ/hemin system that promotes peroxidase-and peroxygenase-type oxidation of different substrates in the presence of an excess of oxidants such as hydrogen peroxide (H 2 O 2 ).…”

Spectroscopic Properties of Two 5′-(4-Dimethylamino)Azobenzene Conjugated G-Quadruplex Forming Oligonucleotides

“…Their involvement in important biological functions, such as telomere maintenance [ 1 , 2 , 3 ], DNA-protein recognition [ 4 , 5 ] and protein inhibition [ 6 , 7 ] has been supposed. Moreover, the stability of Qs in a large variety of experimental conditions has encouraged their exploitation in biotechnology, affording a reliable scaffold for biosensors and nanomechanical devices [ 8 , 9 , 10 ] where they can also form hybrid structures with novel two-dimensional materials [ 11 , 12 ].…”

Magic-angle spinning NMR spectroscopy provides insight into the impact of small molecule uptake by G-quartet hydrogels

“…It is noted that 1 H-13 C CP-MAS NMR experiments have previously been applied to characterize xerogels and organic phases integrated into mesoporous silica. 26,32 However, the low sensitivity of 1 H-X (X = 13 C, 15 N) CP-MAS NMR is a bottleneck, for example, 13 C spectra of xerogels have been acquired by signal averaging several hours to days depending on the swelling solvent. 26 In the case of GB hydrogels containing B2 wt% gel network, 22 carrying out a large number of 1 H-X (X = 13 C, 15 N) CP-MAS NMR titration experiments as a function of increasing concentration of guest molecules (Fig.…”

“…12 Guanosine (G) and its derivatives exhibit rich supramolecular chemistry. [13][14][15][16] The hierarchy of distinct quartet-and ribbonlike structures formed by G-derivatives have been employed to develop stimuli-responsive gels, electrochemical sensors, antiviral gels, synthetic ion channels and liquid crystalline phases. 9,14,[17][18][19][20] Davis and colleagues developed stable and long-lived hydrogels by mixing guanosine and alkali metal borate salts in water (G4ÁM + borate hydrogel, Scheme 1).…”