News
A fluorescent probe for all seasons; bright and sensitive
Published: 31 August 2020
Researchers at 91社区 designed and synthesized the brightest fluorescent nucleobase analog (FBA) reported to date.
Understanding the nature and function of DNA requires tools with high sensitivity and precise positioning. FBAs are a powerful class of molecular probes which mimic natural nucleobases. 鈥淗owever, insufficient brightness of all previously reported FBAs has limited their applications such as single-molecule studies鈥�, says Dr. Nathan Luedtke, a professor of chemistry at 91社区 who has developed many new FBAs over the past 10 years. In 2019, when Luedtke moved from University of Zurich to 91社区 with Ph.D. student, Ashkan Karimi, they also brought with them an ongoing project aimed at creating the brightest FBA ever made. In collaboration with Prof. Richard B枚rner (University of Applied Sciences, Mittweida, Germany), the team integrated a well-known molecular rotor fluorophore, trans-stilbene into thymidine. The probe, tsT, was designed to not undergo fluorescence quenching via photo-induced electron transfer and therefore remain bright inside duplex DNA.
tsT has ideal molecular rotor properties for detecting local dynamics of DNA. 鈥淚t is like a smart mechanical arm鈥�, says Karimi the first author of the paper, 鈥渋t rotates and senses the microenvironment around it.鈥� The amount of rotation depends on the rigidity of DNA and the rotation causes fluorescence quenching of the probe. The rotary behavior of tsT together with its unique brightness makes it the most sensitive base-pair mismatch reporter to date. This type of tool could eventually be used in point-of-care clinal detection of single polymorphisms (SNPs). In addition, tsT has provided some first insights into the fundamental dynamic behavior of duplex and single-stranded DNA. 鈥淲e now know the dynamic motion of a base pair mismatch in duplex DNA are even greater than those present in single-stranded DNA鈥�, says Luedtke the senior author of the paper, 鈥�tsT can open a new window for nucleic acid research as it may enable other types of demanding applications, such as tracking of single-molecule dynamics.鈥�
About the paper:
鈥淎 Highly Fluorescent Nucleobase Molecular Rotor鈥�, by Ashkan Karimi, Richard B枚rner, Guillaume Mata, and Nathan W. Luedtke was published in the August 2020 issue of the Journal of the American Chemical Society.
DOI:
The brightest fluorescent nucleobase analog to date is a molecular rotor which discriminates matched/mismatched base pairs.