Navigation Links
Scientists develop new color-coded test for protein folding

Every protein--from albumin to testosterone (Ed : testosterone isn't a protein, it's a steroid)--is folded into a unique, three-dimensional shape that allows it to function properly. Now Stanford University scientists have developed a simple test that instantly changes color when a protein molecule attached to a gold nanoparticle folds or unfolds. The new technique, which works on the same principle as ordinary pH tests that measure the acidity of water, is described in the March 2005 issue of the journal Chemistry and Biology.

"What we've developed is a simple and inexpensive sensor for determining when a protein changes its conformation," said study co-author Richard N. Zare, the Marguerite Blake Wilbur Professor in Natural Science in Stanford's Department of Chemistry. According to Zare, the new sensor may eventually provide biomedical researchers a fast, affordable method for detecting antibodies and other disease-related proteins. Acid and base

In their experiment, Zare, postdoctoral fellow Soonwoo Chah and graduate student Matthew R. Hammond created a liquid solution containing nano-sized particles of gold saturated with a protein called cytochrome c.

"We chose gold nanoparticles because they are simple to prepare, easy to control and cost effective," the authors wrote. "To the best of our knowledge, however, gold nanoparticles have not been previously used to investigate the folding and unfolding of proteins."

The initial batch of gold-cytochrome solution had a rosy red hue and a pH value of 10--about the same as an over-the-counter heartburn medication. But when drops of hydrochloric acid were added, the solution began to change color, turning purple when the pH reached 5.8 and light blue at pH 4, which is close to the acidity of wine. Lab analysis revealed that additional hydrochloric acid was causing the cytochrome c molecules to unfold. As a result, gold nanoparticles coated with cytochrome c began clumping together --a process that caused the solution to quickly change from red to blue as the acidity increased.

The researchers were surprised to discover that, when the pH was raised from 4 to 10, the blue solution turned reddish once again--a strong indication that some cytochrome c molecules had refolded into their original three-dimensional shape. In fact, the experiment showed that, when attached to gold film, cytochrome c can fold, unfold and refold countless times depending on the acidity of the solution, thus making it an ideal tool for detecting conformational changes in proteins.

"While we're not ready to mass-produce this technology, we believe it will eventually be useful for testing other, more complicated proteins," Zare said, noting that a gold nanoparticle sensor could turn out to be a quick and inexpensive way for doctors to identify antibodies and other signs of infection in the blood stream. Over the next few months, he and his colleagues plan to re-do the experiment using other protein molecules.


'"/>

Source:Stanford University


Related biology news :

1. Scientists ID molecular switch in liver that triggers harmful effects of saturated and trans fats
2. Scientists Replicate Hepatitis C Virus in Laboratory
3. Scientists detect probable genetic cause of some Parkinsons disease cases
4. Scientists find missing enzyme for tuberculosis iron scavenging pathway
5. Scientists seek answers on what activates deadly anthrax spores
6. Yale Scientists Find MicroRNA Regulates Ras Cancer Gene
7. Scientists collaborate to assess health of global environment
8. Scientists decipher genome of fungus that can cause life-threatening infections
9. Scientists discover the cellular roots of graying hair
10. Scientists rid stem cell culture of key animal cells
11. Scientists identify genetic pathways essential to RNA interference
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/17/2017)... Florida , April 17, 2017 NXT-ID, ... technology company, announces the filing of its 2016 Annual Report on ... and Exchange Commission. ... on Form 10-K is available in the Investor Relations section of ... as on the SEC,s website at http://www.sec.gov . ...
(Date:4/11/2017)... Apr. 11, 2017 Research and Markets has ... report to their offering. ... The global eye tracking market to grow at a CAGR of ... Eye Tracking Market 2017-2021, has been prepared based on an in-depth ... market landscape and its growth prospects over the coming years. The ...
(Date:4/5/2017)... SEATTLE , April 5, 2017  The Allen ... the Allen Cell Explorer: a one-of-a-kind portal and dynamic ... large-scale 3D imaging data, the first application of deep ... edited human stem cell lines and a growing suite ... the platform for these and future publicly available resources ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... ... October 11, 2017 , ... The ... endogenous context, enabling overexpression experiments and avoiding the use of exogenous expression plasmids. ... is transformative for performing systematic gain-of-function studies. , This complement to loss-of-function ...
(Date:10/11/2017)... ... October 11, 2017 , ... Proscia ... be hosting a Webinar titled, “Pathology is going digital. Is your lab ready?” ... pathology adoption best practices and how Proscia improves lab economics and realizes an ...
(Date:10/11/2017)... ... October 11, 2017 , ... Disappearing forests and increased emissions are the ... million people each year. Especially those living in larger cities are affected by air ... one of the most pollution-affected countries globally - decided to take action. , “I ...
(Date:10/10/2017)... DIEGO, CALIF. (PRWEB) , ... October 10, 2017 , ... ... as part of its corporate rebranding initiative announced today. The bold new look ... its reach, as the company moves into a significant growth period. , It will ...
Breaking Biology Technology: