While it’s largely business as usual in Cobb’s cities following Tuesday’s municipal elections, Smyrna’s government faces significant change....It would also mean newcomer Lewis Wheaton, a 42-year-old Georgia Tech professor who won 57% of the preliminary vote in the Ward 7 race, would be the only person of color on the council.

At Georgia Tech, members and trainees of the Center for Microbial Dynamics and Infection discuss the identification of pathogen essential genes during coinfections, and how coral management can improve coral defenses against pathogens. Guests were Marvin Whiteley, Gina Lewin, Deanna Beatty, Mark Hay, and Frank Stewart.

Fire ants build living rafts to survive floods and rainy seasons. Georgia Tech scientists are studying if a fire ant colony’s ability to respond to changes in their environment during a flood is an instinctual behavior and how fluid forces make them respond. Hungtang Ko and David Hu will present the science behind this insect behavior, focusing their discussion on how the living raft changes size under various environmental conditions at the American Physical Society’s Division of Fluid Dynamics 72nd Annual Meeting on Nov. 26.

By A. Maureen Rouhi

Examine your hands. The right is a mirror image of the left. They look very similar, but you know they’re not when you try to put your left hand inside a right glove.

The molecules of life have a similar handedness. Proteins for example are like your left hand, made up of amino acids that are all left-handed. This phenomenon is called chirality. How chiral systems emerged is one of the key questions of origins-of-life research.

Many explanations have been proposed. Now a Georgia Tech team examining the problem suggests that stability is what drove the emergence of chiral systems. Led by Jeffrey Skolnick, a professor in the School of Biological Sciences, the team includes  research scientists Hongyi Zhou and Mu Gao. The work was supported in part by the Division of General Medical Sciences of the National Institutes of Health (NIH Grant R35-118039) and published on Dec. 10, 2019, in PNAS.

They reached their conclusion from computer simulations examining the stability and properties of a prepared protein library made up of  

• nonchiral proteins, containing a 1:1 ratio of right- (D) and left-handed (L) amino acids, also called demi-chiral;  
• nonchiral proteins containing 3:1 and 1:3 of D and L amino acids; and
• chiral proteins containing all D and all L amino acids. 

Their simulations showed that nonchiral proteins, even the demi-chiral ones, have many properties of chiral proteins. They fold and form cavities just like ordinary proteins. They could have performed many of the biochemical functions of ordinary proteins, especially the most ancient and essential ones. These nonchiral proteins also can adopt the structures of contemporary proteins including ribosomal proteins, necessary for protein transcription.

“This ability of nonchiral proteins to fold and function might have been an essential prerequisite for the life on Earth,” says Eugene Koonin, a senior investigator at the National Center for Biotechnology Information, in the National Institutes of Health. “If so, this result is a truly fundamental finding that contributes to our understanding of the origins of life.”

However, nonchiral proteins have fewer hydrogen bonds than those made of all D or all L amino acids. The demi-chiral ones have the fewest. Thus chiral proteins are much more stable than demi-chiral ones. “The biochemistry of life as we know it likely results from stability driven by hydrogen bonds,” says Skolnick, who is a member of the Parker H. Petit Institute of Bioengineering and Bioscience.

The PNAS study examines the properties of proteins from the point of view of physics alone, without the intervention of evolution, Skolnick says. “It explains how the chemistry of life emerged from basic physical principles. It also strongly suggests that simple life might be quite ubiquitous throughout the universe.”

“I wish to understand how life emerged and to know its design principles,” Skolnick says. “On the most academic level, I wish to explain the origin of life based on physics with well-defined testable ideas.”

The newly published “work offers a non-intelligent-design perspective as to how the biochemistry of life might have gotten started,” Skolnick says. “It shifts the emphasis from evolution to the inherent physical properties of proteins. It removes that chicken-and-egg quandary that chiral RNA is required to produce chiral proteins. Rather, such excess chirality is shown to emerge naturally from a nonchiral system.”

What the work does not address is why L-amino acids and L-proteins emerged dominant on Earth. It is know that some meteorites have an excess of L-amino acids. “If one assumes that many primordial amino acids were seeded by meteorites, many of them have an excess of L over D amino acids,” Skolnick says. “All it would take is just a little bias to get the whole process started.”

Skolnick says the next step is to test the computer simulations by studying the emergent chemistry of nonchiral proteins.  A key unanswered question is how did replication emerge? “We can explain life’s biochemistry and many of the parts associated with replication from this study, but not replication itself,” he says. “If we can do this, then we have all of life’s components. If this works, ultimately I want to recreate what could be the early living systems in a test tube.” 

Here is the Nov. 5 story from the Cobb County Courier: Georgia Tech Professor Lewis Wheaton Wins Smyrna Ward 7 Council Seat

Lewis Wheaton, associate professor in the School of Biological Sciences, won a council seat in Smyrna Ward 7 after the Nov. 5 elections. He ran on supporting local schools, limiting density, and attracting retail businesses.

In Georgia Tech, Wheaton strives to improve the lives of upper-limb amputees through a deeper understanding of the relationship between the neurophysiology of motor learning and prosthesis adaptation. Since joining Georgia Tech in 2008, he has been directing the Cognitive Motor Control Lab, which aims to understand the neurophysiological processes associated with motor control of the upper limbs.

Wheaton has been leveraging his scientific expertise into community service. In Georgia Tech, he is co-director of Georgia Tech’s working group on Race and Racism in Contemporary Biomedicine.

In the state of Georgia, Wheaton is a Governor-appointed member of the State Rehabilitation Council. Mandated by the U.S. Congress, this council oversees the Georgia Vocational Rehabilitation Agency. In this capacity, Wheaton helps shape rehabilitation policy and management in the state of Georgia.

Wheaton will serve for four years, from Jan. 1, 2020, through Dec. 31, 2023. Meanwhile he will also serve the remaining term of his predecessor, who retired before the election, leaving the seat open.

In the accompanying video clip, Wheaton reflects on his election as follows:

You know, it's remarkable when you think of civic engagement and civic leadership and being a scientist, there are a lot of similarities. It's about being thoughtful. It's about having very clear purpose, having expectations, having goals, and even honestly, having hypotheses, right?

If you think about planning a particular community or thinking about planning a particular road in an area, you have to have an expectation that that road is actually going to be beneficial that’ll actually fit in. It's the same mindset that you do in science, right. You have a project; you have a thought; you think of how this could work, and you, based on those hypotheses, you execute.

Probably the biggest difference is that typically in city management those things are hard things; there are actually structures and things. In science, it doesn't always have to be a hard thing, so that'll be part of the fun.

But really, it's the same concepts. It’s the same ideas, and it's the same very thoughtful approach and really having an innovative approach that guides all of this.

First-year biology major Nabojeet Das has won quiz 8 of ScienceMatters Season 3.

Nabojeet is a first-year biology major from Tucker, Georgia. He says he chose to attend Georgia Tech because "it was closest to home and my cute Shih-Tzu, Zoey," shown with Nabojeet at right. 

Although not yet engaged in research, Nabojeet currently has a federal work-study job as a student assistant in the Histology Core Lab of the Parker H. Petit Institue of Bioengineering and Bioscience. Outside of academics, Nabojeet enjoys spending time with friends and politics. He is a member of the Young Democratic Socialists of America at Georgia Tech and serves as an ambassador for the Explore LLC (Living Learning Community).

Nabojeet usually listens to ScienceMatters when working alone or during his commute. "I love the podcast," he says. "It blows my mind thinking about the global impact of professors – with whom I will eventually take classes –  have made."

In addition, Nabojeet notes that ScienceMatters episodes are "not very long, which makes it super easy to fit into my schedule."  

The quiz question for episode 8 was: What nutrient is pulled out of the air by plants thanks to microbes?

The correct answer is nitrogen. 

Join the Quiz for Episode 9

Episode 9 features James "JC" Gumbart, an associate professor in the School of Physics, and his use of molecular dynamics simulations to chart the possible paths of molecules like proteins in hopes of finding solutions to problems like antibiotic-resistant bacteria.

Here’s the quiz question for episode 9:

What is the term for abnormal protein buildups in the brain?

Submit answer by 5 PM on Monday, Nov 18.

Periodic table t-shirts, must-have beaker mugs, and textured posters perfect for dorm rooms are among the prizes offered to those who are picked at random from all submitting correct answers. Look for the challenge during each week’s new episode, dropping on Tuesdays from Sept. 17 to Nov. 19.