Researchers observe single protein dimers wavering between two symmetrically opposed ... (features of the stability and folding sp...)

Researchers observe single protein dimers wavering between two symmetrically opposed structures

Date:6/19/2009

features of the stability and folding speed of these molecules.

To test if this was true, Deniz and his group at Scripps Research used single-molecule fluorescence resonance energy transfer (smFRET), a tool they have helped develop. This technique, which Deniz calls a "molecular ruler," measures light emitted from two fluorescent dyes that are attached to amino acids in the protein. The color of the measured light provides information about molecular distances that reveals a protein's structure. Observing structures of individual proteins or complexes is an advance over typical ways of measuring complex and dynamic protein structures, which often end up losing information by averaging data over a large number of them, Deniz says.

The scientists studied three different Rop proteinsthe wild type anti, the mutant syn, and another mutant known as A2L2. They found that although the A2L2 was active, it surprisingly configured itself mostly in the syn structure, which was believed to be inactive.

The scientists then altered the protein's environment by adding a little "denaturing" chemical, which helps destabilize the protein structure. They found that as more of this chemical was added, the A2L2 proteins increasingly switched structure from mostly syn to significantly anti by twisting one of the protein copies in the dimer by 180 degrees. Additionally, by using a more complex experiment with an additional differently-colored fluorescent dye, they discovered another surprise. The dimers were able to switch structures without separation of the constituent copies, even though the structure change was very drastic.

"We were able to easily switch A2L2 from an inactive state to one that could bind RNA, and it takes only quite mild changes in conditions to make this change. These direct observations show that this protein dimer has two native structures available to it, and that minor perturbations can cause this balance to be altered," Deniz
'/>"/>

Contact: Keith McKeown
kmckeown@scripps.edu
858-784-8134
Scripps Research Institute
Source:Eurekalert

1

GOOD

Page: 1 2 3 4
Related biology news :

1. Caltech researchers explore how cells reconcile mixed messages in decisions about growth
2. UC Davis researchers visualize formation of a new synapse
3. UBC researchers develop new method to study gambling addictions
4. UCLA cancer researchers develop model that may help identify cancer stem cells
5. Researchers from around the globe coming to K-State June 21 for workshop on Fusarium fungus
6. Duke, Harvard researchers to monitor bonobo reintroduction
7. Rice University researchers ask if biofuels will lead to a drink or drive
8. Aussie and Kiwi researchers make double MS genetic discovery
9. Researchers describe implausible chemistry that produces herbicidal compound
10. Universitat Autonoma de Barcelona researchers first to clone mice in Spain
11. Protein that triggers plant cell division revealed by researchers

Post Your Comments:

Researchers observe single protein dimers wavering between two symmetrically opposed ...(features of the stability and folding sp...)