Navigation Links
Rensselaer professor uncovers mysterious workings of cholera bacteria
Date:7/28/2010

Troy, N.Y. Researchers have found that an enzyme in the bacteria that causes cholera uses a previously unknown mechanism in providing the bacteria with energy. Because the enzyme is not found in most other organisms, including humans, the finding offers insights into how drugs might be created to kill the bacteria without harming humans.

Blanca Barquera, a Rensselaer associate professor of biology, led a team (including research professor Joel Morgan and postdoctoral fellow Oscar Juarez) whose findings were published in the June 28 edition of the Proceedings of the National Academy of Sciences.

The team studied Na+-NQR, an enzyme that is essentially two linked machines to create energy from food and electrically charge the cell membrane of Vibrio cholerae, powering many cellular functions.

Vibrio cholerae causes cholera, a disease transmitted primarily through contaminated drinking water. Cholera, in which severe diarrhea and vomiting lead to rapid dehydration, is a major cause of death in the developing world, and in the aftermath of catastrophes that compromise water systems.

The Rensselaer team found that the way in which the two machines are linked in Na+-NQR is different from other respiratory enzymes and likely involves much more movement of the protein than has been observed in other enzymes.

Their work stems from an interest in cellular respiration. Cellular respiration carries electrons from food to oxygen, in what amounts to a controlled burn. This process releases energy.

"Cellular respiration is remarkable," Barquera said. "It is one of the most efficient energy conversion processes known, and nevertheless, does not require high temperatures. This efficiency has drawn the attention of researchers."

In more complex organisms, like humans, the process of creating energy for a cell respiration takes place in specialized organelles within the cell called mitochondria.

But in bacteria, which lack mitochondria, respiration occurs in the cell membrane. Na+-NQR is a respiratory enzyme found on the cell membrane of Vibrio Cholerae.

The enzyme creates energy through respiration and uses that energy to pump ions out of the cell, electrically charging the cell membrane and providing power for all the functions of the cell. Unlike similar enzymes found in many animals and bacteria, Na+-NQR pumps sodium ions out of the cell, rather than protons.

Barquera's paper in PNAS describes the mechanism the enzyme uses to convert energy using sodium ions.

"Na+-NQR plays the same role as human respiratory proteins but it is much smaller," Barquera said. "We want to understand how it works, how it produces energy. If we understand how Na+-NQR works, we can learn the basic principles used by living organisms to convert energy and transport ions."

Researchers studied the enzyme by removing it from the inner cell membrane and studying it in a solution. Na+-NQR, which prefers an environment of water and oil, flourished in a solution similar to detergent, which mimics the bacterial membrane.

"We have the enzyme off of the membrane with all of its components," Barquera said. Once isolated, the researchers observed the enzyme as it moved sodium from the inside to the outside of the cell.

Their study revealed the protein itself is moving the ions along a path through the cell membrane.

"It works in a very different way from enzymes in other bacteria and mitochondria. The catch and release of ions is done by movement of the protein," Barquera said.

Barquera said that, by modifying the protein in various ways, the researchers had identified the site on the protein where the ions begin and end their travel along the protein.

Next they want to map the route the ion takes along the protein.

"We can see the in and out site. Now we want to know the path," Barquera said.


'/>"/>

Contact: Mary Martialay
martim12@rpi.edu
518-276-2146
Rensselaer Polytechnic Institute
Source:Eurekalert

Related biology news :

1. Left or right? Early clues to soccer penalty kicks revealed at Rensselaer Polytechnic Institute
2. Rensselaer Polytechnic Institute professor Peter M. Tessier named Pew Scholar
3. Rensselaer Polytechnic Institute professor Patrick Underhill receives NSF CAREER award
4. Rensselaer Polytechnic Institute wins $2.45 million grant to support stem cell research
5. Rensselaer researchers to send bacteria into orbit aboard space shuttle Atlantis
6. Rensselaer leads effort to replace 1 of the most widely used drugs in American hospitals
7. Rensselaer receives more than $2 million from New York State to fund stem cell research
8. Trustee makes donation to start new solar energy research center at Rensselaer
9. University of Washington professors lifetime efforts receive international recognition
10. Top professor will report new way to discover drugs that aid regenerative medicine
11. Professor discovers way to slow the growth of malignant melanoma
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/3/2016)... , March 3, 2016  FlexTech, a SEMI ... categories of Innovation, Research & Development, Leadership in Education, ... This is the 9 th year of the ... of companies and individuals from past years . ... on a pre-described set of criteria, by a panel ...
(Date:3/3/2016)... NOTTINGHAM, England and DE SOTO, ... , U.S.-based Stroke Detection Plus® to offer Oncimmune,s ... the risk assessment and early detection of lung cancer ... include large employers, unions and individuals. --> ... employers, unions and individuals. --> Oncimmune, a ...
(Date:3/2/2016)... DUBLIN , March 2, 2016 /PRNewswire/ ... the addition of the "Global Biometrics ... to their offering. --> ... the "Global Biometrics as a Service ... --> Research and Markets ...
Breaking Biology News(10 mins):
(Date:5/2/2016)... NEW YORK , May 2, 2016 ... company announces that its technology partner Mannin Research Inc. ... and Ophthalmology (ARVO), which takes place from May 1-5, ... Research executives will be meeting with its vendors and ... further explore business development goals and other collaborative opportunities ...
(Date:5/2/2016)... ... , ... StarNet Communications Corp, ( http://www.starnet.com/ ) a leading publisher of remote ... modules to its flagship X-Win32 PC X server. The new modules enable X-Win32 ... PC over encrypted SSH. , Traditionally, users of PC X servers deploy the XDMCP ...
(Date:4/29/2016)... ... ... The MIT bioLogic design team has won multiple A' Design Awards ... be applied to fabric and formed into living interfaces between body and environment. They ... The team harvested Natto cells and applied them to fabric with custom 3D printers.The ...
(Date:4/29/2016)... GA (PRWEB) , ... April 29, 2016 , ... ... of medical devices used in spinal surgical procedures, today announced the completion of ... enhanced value proposition for current and future customers and partners. Kohlberg & ...
Breaking Biology Technology: