Senior Micah Heinz knew little about the oxygen-transporting protein hemocyanin before last summer, so naturally, he researched it through the Hillsdale College LAUREATES program.
“It wasn’t something I was familiar with before, but I’ve been interested in it ever since,” Heinz said.
Hemocyanin is found in the blood of arthropod species such as horseshoe crabs and functions similarly to hemoglobin in human blood, except it uses copper instead of iron to bind oxygen.
“It’s a very common protein in a lot of arthropod species, and we don’t understand the mechanism of binding itself,” Heinz said. “Various people [at Hillsdale] have been working on this project.”
Heinz’s research was directed at understanding the mechanism of oxygen binding in hemocyanin. To do so, he experimented with synthetic models of the protein using nitrogen-based ligands.
Previous research done on hemocyanin has focused on other unsuccessful ligands, so Heinz experimented with alternatives. While he was able to successfully get the oxygen to bind, he couldn’t get it to release. As it stands, some ligands that have been studied yielded better results than others.
Heinz said he modeled the research on Kenneth Karlin’s 1987 experiments with hemocyanin at State University of New York at Albany, with the nitrogen-based ligand being one of the various twists.
“We were modeling our research on research done about 30 years ago and were trying different ligands than the ones used there,” Heinz said.
Dean of Natural Sciences and Professor of Chemistry Christopher VanOrman said the research has been going on at Hillsdale for more than 15 years.
“It’s just fundamental research to understand a problem,” VanOrman said. “What I’d like to do is try to synthesize the same ligand that Karlin did.”
That’s exactly what senior Jacob Hann, who is continuing the research at the end of this semester, will attempt to do.
“The type of chemistry this falls under is inorganic chemistry, which is the chemistry of metal-ligand complexes and some of the things they can do,” Hann said. “A specific type of metal-ligand complex is these proteins. Anything that uses oxygen to make energy for itself will have some sort of protein that binds with oxygen and delivers it to the body.”
Hann said the objective of experimentation is to observe a color change, which indicates the ligand in the synthetic model successfully bound to the oxygen.
“Ultimately, what we’d like to accomplish is we get a ligand and get it to complex with the copper and then
get it to reversibly bind with oxygen,” Hann said. “We have a solution with our complex and we bubble oxygen through it, and oxygenate that solution. If you get this complex to bind with oxygen, there’s a color change.”
Heinz and Hann’s different methods of experimentation with hemocyanin are just
two examples of the ongoing process that is researching the protein and synthesizing its active site.
“We didn’t get what we wanted, which is very common in scientific research, but we have good ideas for what other people can do to get better results,” Heinz said.