Navigation Links
UCLA scientists unlock mystery of how 'handedness' arises

The overwhelming majority of proteins and other functional molecules in our bodies display a striking molecular characteristic: They can exist in two distinct forms that are mirror images of each other, like your right hand and left hand. Surprisingly, each of our bodies prefers only one of these molecular forms.

This mirror-image phenomenon known as chirality or "handedness" has captured the imagination of a UCLA research group led by Thomas G. Mason, a professor of chemistry and physics and a member of the California NanoSystems Institute at UCLA.

Mason has been exploring how and why chirality arises, and his newest findings on the physical origins of the phenomenon were published May 1 in the journal Nature Communications.

"Objects like our hands are chiral, while objects like regular triangles are achiral, meaning they don't have a handedness to them," said Mason, the senior author of the study. "Achiral objects can be easily superimposed on top of one another."

Why many of the important functional molecules in our bodies almost always occur in just one chiral form when they could potentially exist in either is a mystery that has confounded researchers for years.

"Our bodies contain important molecules like proteins that overwhelmingly have one type of chirality," Mason said. "The other chiral form is essentially not found. I find that fascinating. We asked, 'Could this biological preference of a particular chirality possibly have a physical origin?'"

In addressing this question, Mason and his team sought to discover how chirality occurs in the first place. Their findings offer new insights into how the phenomenon can arise spontaneously, even with achiral building-blocks.

Mason and his colleagues used a manufacturing technique called lithography, which is the basis for making computer chips, to make millions of microscale particles in the shape of achiral triangles. In the past, Mason has used this technique to "print" particles in a wide variety of shapes, and even in the form of letters of the alphabet.

Using optical microscopy, the researchers then studied very dense systems of these lithographic triangular particles. To their surprise, they discovered that the achiral triangles spontaneously arranged themselves to form two-triangle "super-structures," with each super-structure exhibiting a particular chirality.

In the image that accompanies this article, the colored outlines in the field of triangles indicate chiral super-structures having particular orientations.

So what is causing this phenomenon to occur? Entropy, says Mason. His group has shown for the first time that chiral structures can originate from physical entropic forces acting on uniform achiral particles.

"It's quite bizarre," Mason said. "You're starting with achiral components triangles which undergo Brownian motion and you end up with the spontaneous formation of super-structures that have a handedness or chirality. I would never have anticipated that in a million years."

Entropy is usually thought of as a disordering force, but that doesn't capture its subtler aspects. In this case, when the triangular particles are diffusing and interacting at very high densities on a flat surface, each particle can actually maximize its "wiggle room" by becoming partially ordered into a liquid crystal (a phase of matter between a liquid and a solid) made out of chiral super-structures of triangles.

"We discovered that just two physical ingredients entropy and particle shape are enough to cause chirality to appear spontaneously in dense systems," Mason said. "In my 25 years of doing research, I never thought that I would see chirality occur in a system of achiral objects driven by entropic forces."

As for the future of this research, "We are very interested to see what happens with other shapes and if we can eventually control the chiral formations that we see occurring here spontaneously," he said.

"To me, it's intriguing, because I think about the chiral preference in biology," Mason added. "How did this chiral preference happen? What are the minimum ingredients for that to occur? We're learning some new physical rules, but the story in biology is far from complete. We have added another chapter to the story, and I'm amazed by these findings."

To learn more, a message board accompanies the publication in Nature Communications, an online journal, as a forum for interactive discussion.

This research was funded by the University of California. Kun Zhao, a postdoctoral researcher in Mason's laboratory, made many key contributions, including fabricating the triangle particles, creating the two-dimensional system of particles, performing the optical microscopy experiments, carrying out extensive particle-tracking analysis and interpreting the results.

Along with Mason, co-author Robijn Bruinsma, a UCLA professor of theoretical physics and a member of the California NanoSystems Institute at UCLA, contributed to the understanding of the chiral symmetry breaking and the liquid crystal phases.


Contact: Stuart Wolpert
University of California - Los Angeles

Related biology technology :

1. NTU scientists invent superbug killers
2. Scientists gain new understanding of Alzheimers trigger
3. Scientists develop new technique that could improve heart attack prediction
4. Leading Scientists to Debate Views on Rejuvenation Biotechnologies
5. UCF scientists use nanotechnology to hunt for hidden pathogens
6. Scientists develop tools to make more complex biological machines from yeast
7. UMass Amherst polymer scientists, physicists develop new way to shape thin gel sheets
8. Scientists Discover How a Bacterial Pathogen Breaks Down Barriers to Enter and Infect Cells
9. Design eye for the science guy: Drop-in clinic helps scientists communicate data
10. Scientists learn how to out run damage with imaging technique
11. Receptos Scientists Publish Determination of a High Resolution Sphingosine 1-Phosphate Receptor 1 Structure in Science
Post Your Comments:
Related Image:
UCLA scientists unlock mystery of how 'handedness' arises
(Date:10/8/2015)... N.J. , Oct. 8, 2015  Genetic testing ... may aid the identification of more couples at risk ... a study presented today at the 2015 American Society ... October 10 in Baltimore, Maryland . ... Quest Diagnostics (NYSE: DGX ) are presenting at ...
(Date:10/8/2015)... October 8, 2015 ... --> Goldman Small Cap Research, a ... cap and microcap sectors, announced today that it ... PharmaCyte Biotech, Inc. (OTCQB - PMCB), a publicly ... and preparing treatments for cancer and diabetes. To ...
(Date:10/8/2015)... -- The ALS Association, in partnership with Prize4Life, is pleased ... communication technology solutions for people living with ALS. ... lateral sclerosis) is a progressive neurodegenerative disease that affects ... cord. Eventually, people with ALS lose the ability to ... total paralysis and death within two to five years ...
(Date:10/8/2015)... ... October 08, 2015 , ... Talon Innovations, a provider of Precision Machined ... announces that it is one of three finalists for the Minnesota Business magazine’s Manufacturing ... September 25 Talon Innovations was recognized as a nominee for this competitive award. ...
Breaking Biology Technology:
... international team of scientists has determined the structure of the ... light energy. The team,s results one day could be ... convert solar energy to electrical energy. A research paper ... in the Proceedings of the National Academy of Sciences ...
... Sales Force Reduction and Approximately $45 Million Annual GAAP ... Inc. (Nasdaq: AMLN ) today announced a ... existing primary care and specialty sales forces will merge ... to endocrinologists and diabetes-focused primary care physicians. The changes ...
... The Arcas Group, a leading life-sciences marketing organization, ... Executive Vice President. He will assume responsibility for the ... President of Imedex, Inc."Stefan is an experienced executive who ... company," said Founder and President Jan Heybroek. "I ...
Cached Biology Technology:
(Date:9/30/2015)... -- The global glucose monitoring device and diabetes management market is ... report on the industry from Kalorama Information. Sales in the traditional ... by continuous glucose monitoring and sensor segment, according to the ... products in its latest report, The Global Glucose Monitoring ... , ...
(Date:9/28/2015)...  The monitoring of vital signs, such as ... an essential component of patient assessment. Changes in ... a patient,s condition. However, in general care areas ... during routine observation rounds only once every four ... these observation rounds, the warning signs can go ...
(Date:9/26/2015)... , Sept. 26th, 2015  Results of ... will be unveiled today at the Stanford Medicine ... Engagement Using iPad Dashboards, Connected Health Devices and ... of Pharmacy 3.0, will explain how senior patients ... data to their pharmacist via the TactioRPM remote ...
Breaking Biology News(10 mins):
... to restore vision through the use of a component ... University professor and scientific director of the Ligon Research ... has attracted additional funding for therapy development. The ... affiliate, National Neurovision Research Institute, to RetroSense Therapeutics, LLC, ...
... miniaturized lizards have been identified in Madagascar. These lizards, just tens ... enough to stand on the head of a match, rank among ... found in the Feb. 15 issue of the open access journal ... of the Zoological State Collection of Munich in Germany, also conducted ...
... Invasive species which have the potential to destroy biodiversity ... in the same way as wanted criminals, according to ... Geographic profiling (GP) was originally developed as a statistical ... linked crimes (for example murder, rape or arson) to ...
Cached Biology News:
... : Recombinant human HMGN2/HMG-17 Formulation: ... 0.15M NaCl, 0.05% sodium azide ... to 30% Quality Assurance: routinely ... extracts of murine 10T 1/2 ...
... Dr. P Set from different human ... More organs maybe available upon request. ... items from the whole set, and ... price. All Dr. P Set ...
... Steady gravity-fed delivery of buffer and ... perfusion. Rat version. In Vivo Manual ... gravity-fed delivery of buffer and fixative ... to setup, use and clean--Complete system ...
Biology Products: