Harnessing an emissive guanine surrogate to design small-molecule fluorescent chemosensors of O⁶-methylguanine-DNA-methyltransferase (MGMT)

Abstract

Fluorescence properties of an emissive guanine surrogate, thienoguanine (thGN, 2-aminothieno[3,4-d]pyrimidin-4(3H)-one), were exploited to design two real-time chemosensors of O6-methylguanine-DNA-methyltransferase (MGMT), key DNA repair enzyme involved in the resistance to DNA-alkylating...

A simple and rapid mix-and-read assay for sensitive detection of O6-methylguanine DNA methyltransferase

“…Usually they require harmful radioactive elements, trained operators, and tedious reaction steps, limiting their practical clinical applications. Alternatively, new strategies such as fluorescent methods based on fluorescence-switchable chemical probes, 12 fluorescent guanosine analogs, 13 and DNAzymes 14 have been explored for MGMT detection. Despite their good performance, these methods often require long analysis times, have poor sensitivity, and require complex probe synthesis/purification processes.…”

A chloromethyl-triazole fluorescent chemosensor for O6-methylguanine DNA methyltransferase

“…Fluorescence-based assays to measure MGMT activity have been developed with the aim to address some of the drawbacks of the current methods, owing to their simplicity and more direct nature in measuring MGMT activity. 18,19 To develop a chemosensor, many groups have exploited the fact that MGMT, in addition to repairing O 6 -methylguanine, can also repair bulkier substrates such as O 6 -benzylguanine (O 6 -BG) in DNA or as the free base, whereby C145 would be modified with a larger benzyl group. For example, Kool and colleagues developed a set of MGMT fluorescent chemosensors comprised of a short DNA oligomer containing a fluorophore and O 6 -BG modified with a quencher dye, such that upon repair by MGMT, the O 6 -BG modified quencher are transferred to MGMT, releasing the fluorophore from its quencher on the DNA oligomer causing a light up response.…”