New tool gives researchers a glimpse of biomolecules in motion

January 13, 2009

The ability of biomolecules to flex and bend is important for the performance of many functions within living cells. However, researchers interested in how biomolecules such as amino acids and proteins function have long had to make inferences from a series of X-ray-like “still pictures” of pure crystalline samples.

Now, using a new technique based on terahertz (THz) spectroscopy, scientists at the National Institute of Standards and Technology (NIST) have recently taken the first step toward revealing the hidden machinations of biomolecules in water.*

With wavelengths that range from 1 millimeter to 25 micrometers, terahertz radiation falls between the infrared and microwave spectral regions. Researchers can determine how molecules are moving by passing terahertz radiation through a sample and measuring which wavelengths are absorbed. Unfortunately, room temperature water, the medium in which biological molecules typically are studied, absorbs nearly all of the terahertz radiation, limiting the utility of terahertz spectroscopy for probing biomolecular function.

To avoid the water problem, the NIST team needed to find a way to provide a simple but realistic environment for the biomolecules that contained the least amount of water possible. NIST researcher Ted Heilweil, National Research Council postdoctoral fellow Catherine Cooksey and NIST Summer Undergraduate Research Fellow Ben Greer from Carnegie Mellon University found their solution in the form of nanoscale droplets made of soap-like molecules called micelles.

Using the micelles as tiny test tubes, the team filled the hollow molecules with a small sample of water and the amino acid L-proline, a protein building block. Measurements validated their hypothesis that the micelles would provide an aqueous environment that allows the amino acid to flex and bend while limiting the absorption of the terahertz radiation by water. The terahertz measurements on this simple biomolecule compared well with expectations from other studies, further validating the technique.

According to Heilweil, this study is an important first step toward using terahertz radiation for studying biomolecules. More ambitious measurements on larger molecules such as small peptides, proteins, and DNA fragments will be more challenging, but he says it may be possible in the near future.

“If we can get larger molecules in [the micelles], we can get a much better idea of how living molecules function,” Heilweil said. “This will let us see the basic, most fundamental building blocks of life as they move, which is very exciting.”

* C. Cooksey, B. J. Greer and E. J. Heilweil. Terahertz spectroscopy of l-proline in reverse aqueous micelles. Chemical Physics Letters. Available online Nov. 21, 2008.

Source: National Institute of Standards and Technology

Explore further: Sponge creates steam using ambient sunlight

Related Stories

Sponge creates steam using ambient sunlight

August 22, 2016

How do you boil water? Eschewing the traditional kettle and flame, MIT engineers have invented a bubble-wrapped, sponge-like device that soaks up natural sunlight and heats water to boiling temperatures, generating steam ...

Solar activity has a direct impact on Earth's cloud cover

August 25, 2016

A team of scientists from the National Space Institute at the Technical University of Denmark (DTU Space) and the Racah Institute of Physics at the Hebrew University of Jerusalem has linked large solar eruptions to changes ...

Iron found in fossils suggests supernova role in mass dying

August 22, 2016

Outer space touches us in so many ways. Meteors from ancient asteroid collisions and dust spalled from comets slam into our atmosphere every day, most of it unseen. Cosmic rays ionize the atoms in our upper air, while the ...

How do we colonize Mercury?

August 4, 2016

Humanity has long dreamed of establishing itself on other worlds, even before we started going into space. We've talked about colonizing the Moon, Mars, and even establishing ourselves on exoplanets in distant star systems. ...

We've been wrong about the origins of life for 90 years

August 16, 2016

For nearly nine decades, science's favorite explanation for the origin of life has been the "primordial soup". This is the idea that life began from a series of chemical reactions in a warm pond on Earth's surface, triggered ...

Recommended for you

Electrons at the speed limit

August 26, 2016

Electronic components have become faster and faster over the years, thus making powerful computers and other technologies possible. Researchers at ETH Zurich have now investigated how fast electrons can ultimately be controlled ...

Understanding nature's patterns with plasmas

August 23, 2016

Patterns abound in nature, from zebra stripes and leopard spots to honeycombs and bands of clouds. Somehow, these patterns form and organize all by themselves. To better understand how, researchers have now created a new ...

Light and matter merge in quantum coupling

August 22, 2016

Where light and matter intersect, the world illuminates. Where light and matter interact so strongly that they become one, they illuminate a world of new physics, according to Rice University scientists.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.