Featured Research

from universities, journals, and other organizations

Discovery To Aid Study Of Biological Structures, Molecules

Date:
August 24, 2009
Source:
Purdue University
Summary:
Researchers in the United States and Spain have discovered that a tool widely used in nanoscale imaging works differently in watery environments, a step toward better using the instrument to study biological molecules and structures.

Researchers in the United States and Spain have discovered that an atomic force microscope - a tool widely used in nanoscale imaging - works differently in watery environments, a step toward better using the instrument to study biological molecules and structures. The researchers demonstrated their new understanding of how the instrument works in water to show details of the mechanical properties of a virus called Phi29. The images in "a" and "c" show the topography, and the image in "b" shows the different stiffness properties of the balloonlike head, stiff collar and hollow tail of the Phi29 virus, called a bacteriophage because it infects bacteria.
Credit: C. Carrasco-Pulido, P. J. de Pablo, J. Gomez-Herrero, Universidad Autonoma de Madrid, Spain

Researchers in the United States and Spain have discovered that a tool widely used in nanoscale imaging works differently in watery environments, a step toward better using the instrument to study biological molecules and structures.

Related Articles


The researchers demonstrated their new understanding of how the instrument - the atomic force microscope - works in water to show detailed properties of a bacterial membrane and a virus called Phi29, said Arvind Raman, a Purdue professor of mechanical engineering.

"People using this kind of instrument to study biological structures need to know how it works in the natural watery environments of molecules and how to interpret images," he said.

An atomic force microscope uses a tiny vibrating probe to yield information about materials and surfaces on the scale of nanometers, or billionths of a meter. Because the instrument enables scientists to "see" objects far smaller than possible using light microscopes, it could be ideal for studying molecules, cell membranes and other biological structures.

The best way to study such structures is in their wet, natural environments. However, the researchers have now discovered that in some respects the vibrating probe's tip behaves the opposite in water as it does in air, said Purdue mechanical engineering doctoral student John Melcher.

Purdue researchers collaborated with scientists at three institutions in Madrid, Spain: Universidad Autónoma de Madrid, Instituto de Ciencia de Materiales de Madrid and the Centro Nacional de Biotecnología.

Findings, which were detailed in a paper appearing online last week in the U.S. publication Proceedings of the National Academy of Sciences, are related to the subtle differences in how the instrument's probe vibrates. The probe is caused to oscillate by a vibrating source at its base. However, the tip of the probe oscillates slightly out of synch with the oscillations at the base. This difference in oscillation is referred to as a "phase contrast," and the tip is said to be out of phase with the base.

Although these differences in phase contrast reveal information about the composition of the material being studied, data can't be properly interpreted unless researchers understand precisely how the phase changes in water as well as in air, Raman said.

If the instrument is operating in air, the tip's phase lags slightly when interacting with a viscous material and advances slightly when scanning over a hard surface. Now researchers have learned the tip operates in the opposite manner when used in water: it lags while passing over a hard object and advances when scanning the gelatinous surface of a biological membrane.

Researchers deposited the membrane and viruses on a sheet of mica. Tests showed the differing properties of the inner and outer sides of the membrane and details about the latticelike protein structure of the membrane. Findings also showed the different properties of the balloonlike head, stiff collar and hollow tail of the Phi29 virus, called a bacteriophage because it infects bacteria.

"The findings suggest that phase contrast in liquids can be used to reveal rapidly the intrinsic variations in local stiffness with molecular resolution, for example, by showing that the head and the collar of an individual virus particle have different stiffness," Raman said.

The research was funded by the National Science Foundation and was conducted at the Birck Nanotechnology Center in Purdue's Discovery Park. The biological membrane images were taken at Purdue, and the virus studies were performed at the Universidad Autónoma de Madrid.

The paper was authored by Melcher; Carolina Carrasco, a postdoctoral researcher at Universidad Autónoma de Madrid and the Instituto de Ciencia de Materiales de Madrid; Purdue postdoctoral researcher Xin Xu; José L. Carrasco, a researcher at Departmento de Estructura de Macomoléculas, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas; Julio Gómez-Herrero and Pedro José de Pablo, both researchers from Universidad Autónoma de Madrid; and Raman.


Story Source:

The above story is based on materials provided by Purdue University. Note: Materials may be edited for content and length.


Cite This Page:

Purdue University. "Discovery To Aid Study Of Biological Structures, Molecules." ScienceDaily. ScienceDaily, 24 August 2009. <www.sciencedaily.com/releases/2009/08/090811191654.htm>.
Purdue University. (2009, August 24). Discovery To Aid Study Of Biological Structures, Molecules. ScienceDaily. Retrieved November 28, 2014 from www.sciencedaily.com/releases/2009/08/090811191654.htm
Purdue University. "Discovery To Aid Study Of Biological Structures, Molecules." ScienceDaily. www.sciencedaily.com/releases/2009/08/090811191654.htm (accessed November 28, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Friday, November 28, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

NASA's First 3-D Printer In Space Creates Its First Object

NASA's First 3-D Printer In Space Creates Its First Object

Newsy (Nov. 26, 2014) — The International Space Station is now using a proof-of-concept 3D printer to test additive printing in a weightless, isolated environment. Video provided by Newsy
Powered by NewsLook.com
Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Bolivian Recycling Initiative Turns Plastic Waste Into School Furniture

Reuters - Innovations Video Online (Nov. 26, 2014) — Innovative recycling project in La Paz separates city waste and converts plastic garbage into school furniture made from 'plastiwood'. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Blu-Ray Discs Getting Second Run As Solar Panels

Blu-Ray Discs Getting Second Run As Solar Panels

Newsy (Nov. 26, 2014) — Researchers at Northwestern University are repurposing Blu-ray movies for better solar panel technology thanks to the discs' internal structures. Video provided by Newsy
Powered by NewsLook.com
Today's Prostheses Are More Capable Than Ever

Today's Prostheses Are More Capable Than Ever

Newsy (Nov. 26, 2014) — Advances in prosthetics are making replacement body parts stronger and more lifelike than they’ve ever been. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins