Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chemists Discover Proton Mechanism Used by Flu Virus to Infect Cells

25.10.2010
The flu virus uses a shuttle mechanism to relay protons through a channel in a process necessary for the virus to infect a host cell, according to a research project led by Mei Hong of Iowa State University and the Ames Laboratory.

The findings are published in the Oct. 22 issue of the journal Science.

Hong, an Iowa State professor of chemistry and an associate of the U.S. Department of Energy¡¯s Ames Laboratory, said her research team used solid-state nuclear magnetic resonance (NMR) spectroscopy to determine the structure and workings of the proton channel that connects the flu virus to a healthy cell.

She said a full understanding of that mechanism could help medical researchers design drugs that stop protons from moving through the channel.

That proton channel is an important part of the life cycle of a flu virus. The virus begins an infection by attaching itself to a healthy cell. The healthy cell surrounds the virus and takes it inside through a process called endocytosis. Once inside the cell, the virus uses a protein called M2 to open a channel. Protons from the healthy cell flow through the channel into the virus and raise its acidity. That triggers the release of the virus¡¯ genetic material into the healthy cell. The virus then hijacks the healthy cell¡¯s resources to replicate itself.

Hong and her research team ¨C Fanghao Hu, an Iowa State doctoral student in chemistry; and Wenbin Luo, a former Iowa State doctoral student who is now a spectroscopist research associate at Penn State University ¨C focused their attention on the structure and dynamics of the proton-selective amino acid residue, a histidine in the transmembrane part of the protein, to determine how the channel conducts protons. Their work was supported by grants from the National Science Foundation and the National Institutes of Health.

Two models had been proposed for the proton-conducting mechanism:

¡ñ A ¡°shutter¡± channel that expands at the charged histidine because of electrostatic repulsion, thus allowing a continuous hydrogen-bonded water chain that takes protons into the virus.

¡ñ Or a ¡°shuttle¡± model featuring histidine rings that rearrange their structure in some way to capture protons and relay them inside.

Hong¡¯s research team found that the histidine rings reorient by 45 degrees more than 50,000 times per second in the open state, but are immobile in the closed state. The energy barrier for the open-state ring motion agrees well with the energy barrier for proton conduction, which suggests that the M2 channel dynamically shuttles the protons into the virus. The chemists also found that the histidine residue forms multiple hydrogen bonds with water, which helps it to dissociate the extra proton.

¡°The histidine acts like a shuttle,¡± Hong said. ¡°It picks up a proton from the exterior and flips to let it get off to the interior.¡±

The project not only provided atomic details of the proton-conducting apparatus of the flu virus, but also demonstrated the abilities of solid-state NMR.

¡°The structural information obtained here is largely invisible to conventional high-resolution techniques,¡± the researchers wrote in their Science paper, ¡°and demonstrates the ability of solid-state NMR to elucidate functionally important membrane protein dynamics and chemistry.¡±

Mei Hong, Chemistry and Ames Laboratory, 515-294-3521, mhong@iastate.edu
Mike Krapfl, News Service, 515-294-4917, mkrapfl@iastate.edu

Mike Krapfl | Newswise Science News
Further information:
http://www.iastate.edu

Further reports about: Flu Outbreak Iowa NMR ProTon Science TV Virus chemists discover flu virus healthy cell infect methanol fuel cells

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Researchers invent tiny, light-powered wires to modulate brain's electrical signals

21.02.2018 | Life Sciences

The “Holy Grail” of peptide chemistry: Making peptide active agents available orally

21.02.2018 | Life Sciences

Atomic structure of ultrasound material not what anyone expected

21.02.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>