Researchers map iron transport protein - may help people suffering from blood iron disorders

Montana State University scientists in the Department of Chemistry and Bio-chemistry published new research this week that could one day affect the lives of millions around the world who suffer from blood iron disorders.

The paper, which will appear in the Proceedings of the National Academy of Sciences, details the work of Associate Professor Martin Lawrence and doctoral candidate Anoop Sendamarai. The pair have spent the past two years studying Steap3, a protein involved in regulating the body's absorption of iron.

The results of their studies - the first three-dimensional maps of the atoms that make up Steap3 - could allow pharmaceutical companies to someday design drugs to regulate iron levels in the blood.

"Iron is essential," Lawrence said. "You can't live without it, but it's a double-edged sword. Too much of a good thing can kill you."

Iron serves several important functions in the bloodstream. It carries oxygen, transports electrons within cells and plays an important role in enzyme systems.

Iron irregularities are some of the most common blood disorders in the world. According to the World Health Organization, iron deficiency, which can lead to anemia, affects more than a billion people around the world and can cause developmental and immune system problems.

Conversely, having too much iron, a condition called hemochromatosis, can also hurt the body by releasing destructive free radicals, Lawrence said. Hemochromatosis affects about one in every 300 people and is most common in people of northern European ancestry. Left untreated, it can lead to early death, often by age 50.

"We're struck by how many people have too much or too little iron," Lawrence said.

To understand Steap3's role in transporting and maintaining balanced levels of iron, Lawrence and Sendamarai first had find and purify samples of the protein and then turn those samples into crystals.

Lawrence said the result of the crystallization process, if done correctly, is analogous to the rigid structure of a brick wall. If done incorrectly, it more closely resembles a pile of bricks.

"It's kind of a black art really more than a science," Lawrence said. "You can't always predict the kind of witch's brew that needs to be around to get it to crystallize."

He said only a handful of labs in the country are crystallizing iron transport proteins like Steap3, a fact that places MSU on the same shelf as places like Harvard Medical School.

Once crystallized, the samples are shot with a powerful X-ray beam. Electrons in the sample diffract the X-rays, creating patterns on a digital sensor. The technique, called X-ray crystallography, has been used since the 1950s to de-termine the structure of different substances.

In their basement lab in the campus's New Chemistry Building, Lawrence and Sendamarai then examined the diffraction patterns created by Steap3.

"It's kind of like a contour map," Sendamarai said. "Whenever we see the peaks, we know there are atoms."

Working backward, they can mathematically determine the position of atoms in the protein and display them in three dimensions.

The computer-drawn result, a three-dimensional image that resembles tangled ribbons and strings, is an picture of what the atoms of Steap3 look like.

Sendamarai said having that picture, which depicts all the nooks and crannies on the protein's surface, could allow drug companies to design drugs to fit those spots like puzzle pieces.

If a future drug fits those nooks just right, it could help treat hemochroma-tosis. From there, Sendamarai said it would be conceivable to work backward and possibly treat iron deficiencies or anemia.

Lawrence said that Steap3 is only one in a family of proteins that affect iron transport. This summer, in addition to continuing to study Steap3, Lawrence and Sendamarai hope to learn whether the lab will receive a grant from the National Institutes of Health to work on other iron transport proteins.

"It's a critical step towards toward learning to modulate iron levels in pa-tients with too much or too little iron," Sendamarai said. "But, there are a lot of question marks left in iron transport. It's a big field."

Comments

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of News Medical.
Post a new comment
Post

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.

You might also like...
Incorrect arm positioning inflates blood pressure readings, risking misdiagnosis