By Cara Penquite | Bond LSC
What started as an email correspondence between two aptamer enthusiasts rapidly snowballed into a hat trick of authorships for Donald Burke.
“I was contacted by a student in India asking if I would be an external advisor for her Ph.D. committee,” said Burke, a principal investigator at MU’s Bond Life Sciences Center.
Burke’s extensive research with sticky molecules called aptamers — totaling about 60 publications over 30 years — makes him an expert in the field of aptamer technologies. When Ph.D. student Shringika Soni at Amity University in Noida, India, near New Delhi, began characterizing the use of these molecules for drug testing in a literature review, she turned to Burke for advice on her work. The connection soon turned into a mentorship through regular email correspondence.
“I told her that I was interested in the kinds of things that she does, and I would be happy to interact with her about her science,” Burke said.
That project led Burke to collaborate on a project that attempts to create a rapid test to detect various drugs. This test would provide quicker information than waiting for the results of a blood or urine sample to be returned from a laboratory.
Starting out as a literature review, it soon turned into experimental research at Amity University. Burke’s role from halfway around the world was to ask tons of questions.
“There were a lot of back-and-forth emails around the general idea of defining precisely what her message was, what did she want to say about these systems, and as a particular case study might be mentioned, how much detail should be talked about in the review article,” Burke said.
While the research is not ready to be used commercially, Burke suggests potential applications could be for police officers who suspect drug use or for medical personnel trying to respond quickly to an affected individual.
“Maybe you’re suspicious that [someone is] on a particular drug. Having them spit onto a stick is just a whole lot less invasive and quicker,” Burke said.
Detection of the drugs falls to sticky molecules called aptamers. Essentially a chain of nucleotides folded into a particular shape, aptamers are selective in what they stick to, and each aptamer sticks to a specific compound. The researchers engineered their own aptamers that can stick to particular compounds found in certain drugs.
“The two major layers to this technology are designing the sensor components so that it will bind to the [compounds] really well and specifically,” Burke said. “The second component is to somehow turn that binding event into a detectable signal.”
But, aptamers just sticking to a drug is not enough because the researchers also need a signal to know the aptamer detected it.
To sense the chemical interaction, the researchers focused on electrical currents. With no drugs present, the aptamers do not stick to anything, and the electrical current flows. In contrast, when there are drugs present the aptamers stick to the compounds and block the electrical current from flowing. This allows the researchers to measure the drugs in the solution.
Due to Burke’s help on the project, the research team at Amity University offered to list Burke as a co-corresponding author.
“I just didn’t think that was appropriate, they were the ones leading the charge,” Burke said. “My role was to ask them questions from time to time and to push them to make sure they rounded out their arguments.”
This project adds to Burke’s long list of aptamer research fueled by his fascination with the properties of molecules driving living things.
“Just about every aspect of biology is driven by this choreography of who’s dancing with whom, by which molecules dance with which other molecules,” Burke said. “But why is it that some of the players refuse to dance with certain other players and others are just immediately drawn to certain other players?”
Burke’s research tries to answer these questions and determine why some molecules interact with specific compounds and why others do not.
“When you look at molecules the way they interact, it’s just so fun to watch the dance that they actually do,” Burke said.
Donald Burke is a professor of molecular microbiology and immunology and a joint professor of biochemistry. His collaboration resulted in publications in the Journal of Electroanalytical Chemistry, Biosensors, and Surfaces and Interfaces.
