According to the article, scientists have long known what materials are at work in the firefly’s body — they just didn’t know how they worked together to produce the light emitted by the insects.
“The way enzymes and proteins can convert chemical energy into light is a very basic phenomenon,” Branchini told the magazine, “and we wanted to know how that biochemical process worked.”
The research by Branchini and his team was initially reported in a paper featured in the Journal of the American Chemical Society. Their findings have broad implications that could apply to other bioluminescent organisms and could help inform new discoveries in medicine, military technology and other important fields.
Branchini, the Hans and Ella McCollum ’21 Vahlteich Professor of Chemistry and a member of the Connecticut College faculty since 1986, is an expert on the biochemistry of bioluminescence, or the process by which living organisms convert chemical energy into light. As director of the College's Bioluminescence Research Group, Branchini has mentored and overseen the research activities of more than 85 undergraduate students. The group is recognized world-wide as a leader in the field of bioluminescence.
"We've done a lot of research in this field, and I'm very pleased with the way our work has been received," Branchini has said. "It's a topic that has interested me for more than 35 years, and with the exciting discoveries we make every year, it continues to be a topic that is interesting and relevant to our undergraduates."
Branchini’s latest discovery looks closely at the cascade of reactions that allows fireflies to produce light. They knew it started with a chemical called luciferin, which interacts with the energy-transporting molecule adenosine triphosphate, or ATP. The product of that reaction then combines with oxygen and, in turn, releases light. Branchini’s group wanted to know more about the exact steps, so they explored potential mechanisms in the lab.
They experimented with the enzyme luciferase, which boosts the initial reaction between luciferin and ATP, under varying conditions. In contrast to the commonly accepted model, the resulting data suggest that the transfer of a single electron to oxygen occurs during one of the final steps to spur light production. Branchini's mechanistic results may represent a unifying feature of the highly diverse natural phenomenon.
“We were able to do a number of experiments that allowed us to confirm and further the basic knowledge of how the biochemistry works,” Branchini said.
Branchini’s research has received significant support. In 2014, Branchini received $599,386 from the National Science Foundation (NSF) through its Research at Undergraduate Institutions program, and in 2009, he received an NSF research grant for $582,899. These are two of several NSF grants he has been awarded to cover expenses for student research stipends, international travel, major equipment acquisition and building renovations. In 2010, and again in 2014, he received $225,000 grants from the Air Force Office of Scientific Research.
Branchini’s work also earned the College its first patent. In 2011, the United States Patent and Trademark Office issued U.S. Patent No. 7,807,429 for an enhanced version of an Italian firefly's light emitting protein engineered by Branchini and his research team. The College was also issued a European patent based on the U.S. patent.