Researchers say by enabling the creation of superoxide, a highly reactive electron-rich oxygen ion, we can protect against cancer.

Superoxide is involved in the destruction of damaged cells and therefore is important in preventing the development and spread of cancer. The protein proline dehydrogenase "opens up to allow oxygen to 'steal' electrons" and create a superoxide, said Tommi A. White, an MU doctoral student in biochemistry.

White and his team are working to create the first model of proline dehydrogenase. Because the human form of this enzyme is difficult to work with, the team studied proline dehydrogenase from the bacteria thermus thermophilus . They used bioinformatics and biochemical studies to show that this enzyme is functionally similar to the human version, so their results can be generalized to the human version, as well as the bacterial version.

Using X-ray crystallography and biochemical analysis, the team created a model of proline dehydrogenase that can tell scientists more about the molecule's structure and functions.

"The three-dimensional model tells us a lot about the structure of the molecules and helps us understand how they work," Tanner said.

"This protein is important in cancer prevention because it enables the creation of superoxide, which aid in cell death. Cells aren't meant to live forever, and at some point, they need to die and be destroyed. Cells that are damaged or diseased are usually destroyed in this process."

White said it's unusual for proline dehydrogenase to be involved in such a process because the usual job of this type of enzyme is to transfer electrons to the mitochondrial membrane, not allow them to be attached to oxygen to create highly reactive superoxides.

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