Featured Research

from universities, journals, and other organizations

Fluorescent Proteins Developed For Live Cell Imaging, Biosensor Design

Date:
February 8, 2008
Source:
Carnegie Mellon University
Summary:
Scientists have developed new "fluorogen activating proteins" that will become a key component of novel molecular biosensor technology. The FAPs can be used to monitor biological activities of individual proteins and other biomolecules within living cells in real time. Researchers designed the FAPs to emit fluorescent light only when bound to a fluorogen, an otherwise non-fluorescent dye added by the scientists. This feature will allow biologists to track proteins on the cell surface and within living cells in very simple and direct ways, eliminating cumbersome experimental steps.

Scientists at Carnegie Mellon University's Molecular Biosensor and Imaging Center (MBIC) have developed new "fluorogen activating proteins" (FAPs) that will become a key component of novel molecular biosensor technology being created at Carnegie Mellon. The FAPs, which can be used to monitor biological activities of individual proteins and other biomolecules within living cells in real time, are described in the February issue of Nature Biotechnology.

Carnegie Mellon scientists designed the FAPs to emit fluorescent light only when bound to a fluorogen, an otherwise non-fluorescent dye added by the scientists. This feature will allow biologists to track proteins on the cell surface and within living cells in very simple and direct ways, eliminating cumbersome experimental steps.

Scientists say the fluorogen activating proteins are especially useful for developing molecular biosensors, because FAPs allow researchers to not only see where the target protein is within the space of the cell, but also to see color changes when it becomes fluorescent. Color changes may reflect changes in the local environment of the protein, and allow quantitative sensing in real time of the biological activity of proteins and biomolecules that are in close proximity to each other.

Biologists often have a difficult time locating a target biomolecule inside living cells using other dye technologies because of background light given off by any unbound dye molecules. This background light obscures the biomolecule's glow and therefore must be removed to successfully carry out the experiment.

The new FAP technology gives off light only when and precisely where the target biomolecule is present, enabling scientists to activate the fluorescence when needed to see exactly where in the cell the biomolecule is located. Scientists also can design fluorogens that can enter the cell and fluorogens that can't. When used with fluorogens that are excluded from the cell, the FAP technology provides an exceptionally selective biosensor for proteins at the outside of the cell surface.

The FAP is a specialized single chain antibody (scFv), a recombinant fragment of full-size antibody proteins that the human immune system uses to identify intruders like bacteria or viruses. The Carnegie Mellon scientists screened billions of scFvs to look for those that bound specifically to either of two fluorogens, malachite green and thiazole orange. The team found several scFvs that, when bound to the fluorogen, emitted bright fluorescent signals. They termed these scFvs "fluorogen activating proteins."

"These FAPs are the essential first step in developing molecular biosensors that will monitor dynamic changes occurring within cells," said Alan Waggoner, professor of biological sciences and director of the MBIC. "The ultimate goal is to put molecular biosensors based on FAP technology inside cells, but this current work is immediately useful. We have used the FAPs in conjunction with several fluorogens to visualize proteins at the cell surface and are now using the technology to image proteins inside cells."

The new FAPs are an extension of the genetic approach made popular by the advent of fluorescent proteins, such as green fluorescent protein (GFP), more than a decade ago. GFPs, once expressed in cells, are always aglow when visualized by scientists using special light sources and microscopes. The Carnegie Mellon team has taken GFP technology one step further - with the novel FAPs and associated fluorogens, they can control fluorescence in space and time.

"The beauty of our system is that we can make FAPs with genetic variations so that we can co-express distinct FAPs within a cell. We can also make synthetic variations of the fluorogen that have different fluorescent and binding properties. Together, these modifications will allows us to image multiple colors inside cells, enabling us to dynamically monitor several proteins and follow complex cellular functions," said Chris Szent-Gyorgyi, a research scientist at the MBIC who spearheaded the isolation of the FAPs.

The work, funded by the Pennsylvania Department of Health and the National Institutes of Health (NIH), is part of the mission of an NIH National Technology Center for Networks and Pathways. The effort, headquartered at Carnegie Mellon, is a partnership between Carnegie Mellon and the University of Pittsburgh.


Story Source:

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


Cite This Page:

Carnegie Mellon University. "Fluorescent Proteins Developed For Live Cell Imaging, Biosensor Design." ScienceDaily. ScienceDaily, 8 February 2008. <www.sciencedaily.com/releases/2008/02/080206101405.htm>.
Carnegie Mellon University. (2008, February 8). Fluorescent Proteins Developed For Live Cell Imaging, Biosensor Design. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2008/02/080206101405.htm
Carnegie Mellon University. "Fluorescent Proteins Developed For Live Cell Imaging, Biosensor Design." ScienceDaily. www.sciencedaily.com/releases/2008/02/080206101405.htm (accessed April 23, 2014).

Share This



More Plants & Animals News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Leopard Bites Man in India

Raw: Leopard Bites Man in India

AP (Apr. 22, 2014) A leopard caused panic in the city of Chandrapur on Monday when it sprung from the roof of a house and charged at rescue workers. (April 22) Video provided by AP
Powered by NewsLook.com
Iowa College Finds Beauty in Bulldogs

Iowa College Finds Beauty in Bulldogs

AP (Apr. 22, 2014) Drake University hosts 35th annual Beautiful Bulldog Contest. (April 21) Video provided by AP
Powered by NewsLook.com
805-Pound Shark Caught Off The Coast Of Florida

805-Pound Shark Caught Off The Coast Of Florida

Newsy (Apr. 22, 2014) One Florida fisherman caught a 805-pound shark off the coast of Florida earlier this month. Video provided by Newsy
Powered by NewsLook.com
Breakfast Foods Are Getting Pricier

Breakfast Foods Are Getting Pricier

AP (Apr. 21, 2014) Breakfast is now being served with a side of sticker shock. The cost of morning staples like bacon, coffee and orange juice is on the rise because of global supply problems. (April 21) Video provided by AP
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:
from the past week

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