Blanca Barquera

Blanca Barquera, associate professor of Biology at Rensselaer Polytechnic Institute, has received a nearly $850,000 grant from the National Science Foundation to study a group of proteins that appear to play a vital role in the survival of a multitude of deadly bacteria. The research will delve into how a widely distributed family of proteins called Rnf functions in different types of pathogenic bacteria, including the bacteria that cause cholera, cystic fibrosis, food poisoning, and bubonic plague.

“For a class of enzymes with so many important roles in bacteria, little is known about the structure or mechanisms that the Rnf family uses within the cell,” Barquera said. “Since we are short on antibiotics because of increased bacterial resistance, new antibiotic targets that have not even been considered yet are of particular importance.”

Barquera’s preliminary research indicates that the Rnf family plays a variety of important roles in different bacteria, including those that cause serious illness in humans. With this new funding, Barquera will work to determine if Rnf proteins are essential to the very survival of these bacteria.

“There are very few enzymes in bacteria that are essential,” she said. “Our earliest indications are that Rnf may be one of the rare examples of an essential protein in certain bacteria. This grant is allowing us to delve further into this possibility.”

Barquera is learning that Rnf is involved in converting energy from available sources into forms of energy that the cells need in order to function. She has learned that in at least some cases, Rnf acts much like an electrical substation in a cell that takes energy from the grid and provides that energy where it is required. The grid in these cases appears to be the cell’s electrochemical membrane, according to Barquera.

Rnf is able to tap into this widely distributed energy source in the cell and deliver that energy where it is needed. An example of this energy tapping occurs when a cell traps atmospheric nitrogen to provide the materials necessary to synthesize vital proteins in the cell. The mechanism Rnf uses to perform these functions appears different from what has been seen for any other enzyme.

“The kind of basic understanding of the processes in biology is the foundation on which future development in medicine in biotechnology are built,” she said. “In the specific case of Rnf, the enzyme can be a promising drug target.”

The goals of Barquera’s research under this grant are to clarify the roles that Rnf plays in different organisms and understand the mechanisms Rnf uses to makes these energy conversion functions possible. This will include an understanding of the chemistry and physics of these processes. This knowledge could provide information on new, previously uninvestigated methods to kill harmful bacteria, according to Barquera. Being able to target such an essential enzyme would be a new way for an antibiotic to kill bacteria. Take down an essential protein, she said, and the bacteria will not be able to survive. 

To determine if Rnf is truly an essential protein, Barquera and the members of her research team will use a variety of biochemical and biophysical techniques within the Rensselaer Center for Biotechnology and Interdisciplinary Studies (CBIS).

The research builds off Barquera’s previous research into the inner workings of cholera that was recently published in the Proceedings of the National Academy of Science. A news release on this previous cholera research can be found at http://news.rpi.edu/update.do?artcenterkey=2755.

The title of this new grant is “ Rnf: A New Class of Redox-coupled Ion Transporters.”  The grant will total $843,269 over the next four years.

More information on Barquera can be found at http://www.rpi.edu/dept/bio/faculty/profiles/barquera.html. 

Contact: Gabrielle DeMarco
Phone: (518) 276-6542
E-mail: demarg@rpi.edu