Purdue researchers obtain a snapshot clarifying how materials enter cells
2007-12-06
A group of Purdue University researchers has captured a key step in the metabolic process that allows materials, such as nutrients and drug treatments, to move in and out of cells.
A research team led by Jue Chen, an associate professor of biological sciences, obtained a snapshot of the tiny protein gate complex that opens and closes pathways through the protective cellular membrane. The gates, operated by small protein machines that push them open and closed, bring nutrients into the cell and flush out waste.
The Purdue-led team was the first to achieve an image of the middle step of the process, capturing the molecular interactions as material passes through the membrane.
"By understanding the mechanisms of this process, researchers may be able to design more effective treatments for diseases that involve this group of proteins, such as cancer and cystic fibrosis," said Chen, who also is a member of Purdue's structural biology group within the College of Science. "With this knowledge, researchers may be able to inhibit or activate this mechanism, depending on what is needed to counteract the disease. For instance, many cancer cells are resistant to drug treatments because the cells pump the drugs out through these channels before they can work."
Amy Davidson, who collaborated on this work with Chen, said capturing an image of the intermediate stage is a giant step toward learning the complete process.
"If you look at only the before and after stages, you don't really know all that goes on," said Davidson, an associate professor of chemistry at Purdue. "The intermediate stage provides all of this information about how the process really works. It shows all of the main components of the system interacting, which had not been seen before. It is a snapshot of what happens halfway through the entry process and is a very clear picture of how things work."
The research team used X-ray crystallography to obtain a picture of a special protein, called an ABC tran
