Nanotechnology Now

Our NanoNews Digest Sponsors



Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Study: Honeycomb structure responsible for bacteria's extraordinary sense

Courtesy of Crane Lab
Honeycomb-like hexagonal lattice formed by the network of receptor molecules (pink), associated enzymes (blue) and coupling proteins (green) in motile bacteria. Such a cooperative lattice arranged across their cell membranes helps bacteria sense their environment with extreme sensitivity. Inset shows the structure of a unit cell of the lattice in detail (top left).
Courtesy of Crane Lab

Honeycomb-like hexagonal lattice formed by the network of receptor molecules (pink), associated enzymes (blue) and coupling proteins (green) in motile bacteria. Such a cooperative lattice arranged across their cell membranes helps bacteria sense their environment with extreme sensitivity. Inset shows the structure of a unit cell of the lattice in detail (top left).

Abstract:
Cornell researchers have peered into the complex molecular network of receptors that give one-celled organisms like bacteria the ability to sense their environment and respond to chemical changes as small as 1 part in 1,000.

Study: Honeycomb structure responsible for bacteria's extraordinary sense

Ithaca, NY | Posted on February 20th, 2012

Just as humans use five senses to navigate through surroundings, bacteria employ an intricate structure of thousands of receptor molecules, associated enzymes and linking proteins straddling their cell membranes that trigger responses to external chemical changes.

Researchers in the lab of Brian Crane, professor of chemistry and chemical biology, with collaborators in the lab of Grant Jensen at the California Institute of Technology, have mapped out the honeycomb-like hexagonal arrangement of these receptor complexes in unprecedented detail.

They report their discovery in the Feb. 20 issue of the Proceedings of the National Academy of Sciences.

"The highlight of the paper is that by using a combination of [techniques], we've been able to image these complex arrays in live cells and determine how they are structured -- they are a very unique biological assembly that is conserved across nearly all classes of motile bacteria," said Crane.

The findings might have potential applications in engineering biologically inspired synthetic molecular devices to detect specific chemicals with high sensitivity over a wide dynamic range; they also could shed light on the pathogenesis of various bacterial diseases like syphilis, cholera and Lyme disease. They may also give some insight into the functioning of the human immune system, where special cells may be employing similar cooperative networks of receptors to recognize and fight against foreign antigens, Crane said.

Scientists are trying to determine how one receptor -- on detecting nutrients, oxygen or acidity, for example -- triggers communication through multiple enzymes in the complex, setting off a chain reaction. This cooperation leads to a gain or amplification in the signal that is finally communicated to the tails (flagella) of the bacterium, affecting the way they spin. Such a response allows the bacterium to move toward food sources or away from toxic environments.

The latest work takes a big step toward understanding this mechanism by demonstrating for the first time how the individual pieces of receptors, enzymes and coupling proteins fit together to generate an extended network. It builds on previous work in the Crane lab done in collaboration with Jack Freed, Cornell professor of chemistry and chemical biology.

"We were able to see how the enzymes and proteins are linked together in the complex array and also their interactions with the receptors," said Xiaoxiao Li, graduate student and joint lead author on the study.

High-resolution X-ray images of the bacterial membrane receptor complex were obtained after extraction, purification and crystallization at the Cornell High Energy Synchrotron Source (CHESS). The scientists reconstructed the complicated molecular structure of the complex with an accuracy that is within a nanometer (a billionth of a meter). Pictures of the structure were also captured inside living cells, by first "flash-freezing" the cells and then scattering electrons off them.

The researchers deduced that trimers (groups of three) of receptor molecules are arranged at the vertices of hexagons surrounding rings of enzymes and coupling proteins. These rings linked by proteins form the backbone of the extended honeycomb-like network.

The research was funded by the Howard Hughes Medical Institute, the National Institutes of Health, and the Gordon and Betty Moore Foundation.

Graduate student Vivek Venkataraman is a writer intern for the Cornell Chronicle.

####

For more information, please click here

Contacts:
Media Contact:
John Carberry
(607) 255-5353


Cornell Chronicle:
Krishna Ramanujan
(607) 255-3290

Copyright © Cornell University

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

'Stealth' nanoparticles could improve cancer vaccines October 1st, 2014

Stressed Out: Research Sheds New Light on Why Rechargeable Batteries Fail October 1st, 2014

New Absorber Will Lead to Better Biosensor: Biosensors are more sensitive and able to detect smaller changes in the environment October 1st, 2014

Graphene chips are close to significant commercialization October 1st, 2014

Govt.-Legislation/Regulation/Funding/Policy

Platinum meets its match in quantum dots from coal: Rice University's cheap hybrid outperforms rare metal as fuel-cell catalyst October 1st, 2014

$18-million NSF investment aims to take flat materials to new heights: 2-D alternatives to graphene may enable exciting advances in electronics, photonics, sensors and other applications October 1st, 2014

Novel approach to magnetic measurements atom-by-atom October 1st, 2014

'Stealth' nanoparticles could improve cancer vaccines October 1st, 2014

Nanomedicine

Arrowhead Expands Management Team with Appointment of Susan Boynton as Vice President Global Regulatory Affairs October 1st, 2014

Nanobotmodels present metastasis and angiogenesis medical animation October 1st, 2014

'Stealth' nanoparticles could improve cancer vaccines October 1st, 2014

New Absorber Will Lead to Better Biosensor: Biosensors are more sensitive and able to detect smaller changes in the environment October 1st, 2014

Discoveries

Breakthrough in ALD-graphene by Picosun technology October 1st, 2014

Novel approach to magnetic measurements atom-by-atom October 1st, 2014

Nanoparticles Accumulate Quickly in Wetland Sediment: Aquatic food chains might be harmed by molecules "piggybacking" on carbon nanoparticles October 1st, 2014

'Stealth' nanoparticles could improve cancer vaccines October 1st, 2014

Announcements

'Stealth' nanoparticles could improve cancer vaccines October 1st, 2014

Stressed Out: Research Sheds New Light on Why Rechargeable Batteries Fail October 1st, 2014

New Absorber Will Lead to Better Biosensor: Biosensors are more sensitive and able to detect smaller changes in the environment October 1st, 2014

Graphene chips are close to significant commercialization October 1st, 2014

Nanobiotechnology

Ad-REIC vaccine: A magic bullet for cancer treatment September 30th, 2014

How things coil: Researchers discover that simulation technology designed for Hollywood can be used as a predictive tool for understanding fundamental engineering problems September 29th, 2014

Penn Team Studies Nanocrystals by Passing Them Through Tiny Pores September 26th, 2014

New NIH/DOE Grant for Life Science Studies at NSLS-II: Funding will support operation of three powerful experimental stations designed to reveal detailed structures of proteins, viruses, and more September 23rd, 2014

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE