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The Weeks Group

The Weeks Group

The Weeks Laboratory invents novel chemical microscopes for understanding the structure and functions of RNA and then applies these unique technologies to leading, and previously intractable, problems in biology. Current projects investigate the basic science of RNA chemistry; meld molecular chemistries with genome-scale readouts of RNA structure; focus on the genome structure and biology of human viruses, especially HIV; and create new therapeutics directed against viruses and human genetic disease. Most projects in the laboratory span fundamental chemistry or technology development and ultimately lead to practical applications in virology, next-generation structure analysis, or understanding biological processes in living cells. Collectively, this work has led to extensive recognition of student and postdoctoral colleagues in the laboratory.

 

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Goldwater Scholar

We are very proud to announce that Kaitlyn Tsai has been selected as a Barry Goldwater Scholar. The Barry Goldwater Scholarship Program was established by Congress in 1986 to honor Senator Barry Goldwater, who served his country for 56 years as a soldier and statesman, including 30 years of service in the U.S. Senate. The purpose of the Foundation is to provide a continuing source of highly qualified scientists, mathematicians, and engineers by awarding scholarships to college students who intend to pursue research careers in these fields.

Kaitlyn Tsai

Kaitlyn Tsai is from Apex, North Carolina where she went to Apex High School. She feels that she came to the Department of Chemistry at Carolina, almost by accident since she came in with a lot of AP credit. Later, she has come to believe that choosing chemistry was one of the best decisions she could have made for her undergraduate studies. She claims that "between the amazing faculty and extensive opportunities for research," she has "become more inspired to pursue chemistry research." Her initial choice was to start as Chemistry B.S. major, but after taking genetics, she became more interested in the biological applications of chemistry and switched to the biochemistry track. Kaitlyn is currently conducting research in Dr. Marcey Waters' Bioorganic Chemistry lab, where she is part of a team investigating protein binding involved in histone methylation for epigenetic regulation. Dysregulation of histone methylation has been associated with certain types of cancers, and the eventual development of inhibitors molecules to correct for epigenetic malfunction is the end goal of this research. After graduation, Kaitlyn intends to enroll in a Ph.D. program in Chemistry, and hopes to continue epigenetic research. She would also like to stay in academia since it would give her the opportunity to teach and mentor. -Congratulations to the very prestigious award, Kaitlyn!

 

Two Awards for Hogan

First, Professor Brian Hogan was recognized with a University Diversity Award, then, just a few days later selected as the 2015 recipient of the Carolina Chiron Award. The former recognizes significant contribution to the enhancement, support and/or furtherance of diversity on our campus and in the community.

Brian Hogan

The recipient of the Carolina Chiron Award is selected by a committee of undergraduate students, representing a wide range of student groups, considering a large pool of nominations, Professor Hogan was selected for his commitment to students both inside and outside the classroom. They believe that he exemplifies what the Chiron Award stands for: excellence in teaching and going above and beyond to help students succeed. Congratulations, Professor Hogan!

 

Commencement 2015

Commencement

The Chemistry Department's Commencement Ceremony will be held on Sunday, May 10, 2015, at the Friday Center Atrium and Grumman Auditorium immediately following the University-wide Commencement Ceremony.

A reception will begin at 12:00 pm, followed at 1:15 pm by the Chemistry ceremony, consisting of the formal awarding of degrees and presentation of awards to selected undergraduate students.

 

In-Cell Ribosome Structure Resolved

It has been known for decades that the ribosome, the cellular complex that synthesizes proteins, interconverts between "active" and "inactive" conformations. However, the physiological relevance of this widely observed switch remained unclear and unknown.

Research Images

Jennifer McGinnis, in the Weeks Lab, led a study, published in PNAS, in which newly developed in-cell SHAPE technologies were used to probe the structure of the ribosome in healthy living cells. In cells, one class of ribosome subunits exists predominantly in the classic "inactive" conformation and disrupting the ability to interconvert between active and inactive conformations compromises protein synthesis. In-cell RNA structure probing thus resolved this 40 year old challenge to reveal that the inactive state regulates ribosome function as a conformational switch.

 

New Avenues in Solar Fuel Production

Chemists have long sought new ways to create energy-rich fuels - ideally via reactions powered by a renewable resource such as the sun. But scientists still have a lot to learn about solar-powered reactions, and a new study by Thomas Eisenhart and Jillian Dempsey sheds light on how they occur. The proton-coupled electron transfer reaction, PCET, is a key light-driven step in the conversion of small molecules into energy-rich fuels. Although prior research has provided a basic understanding of PCET reactions between molecules in their ground states, much less is known about the reactions between electronically excited molecules.

Research Image

In the article, which made the cover of JACS, and was also featured in JACS Spotlights, the team reports results from a mechanistic study of excited-state PCET reactions between two small molecules, acridine orange and tri-tert-butylphenol. The step-by-step process by which the reaction occurs has not been determined previously, but since each of the reaction components has a unique spectroscopic signature, the researchers can monitor each step with transient absorption spectroscopy. The results help explain the intimate coupling of light absorption with both proton and electron transfer, which the authors say will help pave the way for new avenues in solar fuel production.

Christine Herman, Ph.D., JACS

 

Hopping Diffusion of Nanoparticles

In a collaborative work, published in Macromolecules, researchers in the Rubinstein Group propose a hopping mechanism for diffusion of large nonsticky nanoparticles subjected to topological constraints in both unentangled and entangled polymer solids, networks and gels, and entangled polymer liquids, melts and solutions. Probe particles with size larger than the mesh size ax of unentangled polymer networks or tube diameter ae of entangled polymer liquids are trapped by the network or entanglement cells. At long time scales, however, these particles can diffuse by overcoming free energy barrier between neighboring confinement cells.

Research Images

The terminal particle diffusion coefficient dominated by this hopping diffusion is appreciable for particles with size moderately larger than the network mesh size ax or tube diameter ae. Much larger particles in polymer solids will be permanently trapped by local network cells, whereas they can still move in polymer liquids by waiting for entanglement cells to rearrange on the relaxation time scales of these liquids. Hopping diffusion in entangled polymer liquids and networks has a weaker dependence on particle size than that in unentangled networks as entanglements can slide along chains under polymer deformation. The proposed novel hopping model enables understanding the motion of large nanoparticles in polymeric nanocomposites and the transport of nano drug carriers in complex biological gels such as mucus.

 

 

At the Department of Chemistry, we feel strongly that diversity is crucial to our pursuit of academic excellence, and we are deeply committed to creating a diverse and inclusive community. We support UNC's policy, which states that "the University of North Carolina at Chapel Hill is committed to equality of opportunity and pledges that it will not practice or permit discrimination in employment on the basis of race, color, gender, national origin, age, religion, creed, disability, veteran's status, sexual orientation, gender identity or gender expression."