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October 2020

Archives for October 2020

ACGS Halloween Costume Contest

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Social events and social distancing don’t necessarily mesh very well! Due to COVID-19, ACGS has decided to do a socially distant Halloween Costume Contest to bring some very spooky cheer to the department in lieu of a fall social. All faculty, staff, lecturers, post-docs, and graduate students are invited to participate and show off their creative side!

November 2nd-9th, polls will open through email and best dressed will be chosen democratically! Monetary prizes of $100 for 1st place, $50 for 2nd, and $25/ea for 3rd, 4th, and 5th will be awarded! 

Winners Update:

1st place – Avery Blockmon and Kiman Park “Men in Black”

2nd place – Douglas Stewart “Plague Doctor”

3rd place – Megan Qualls “Mary Poppins”

4th place – Ampofo Darko “Zoom Outfit”

5th place – Eleanor Page “James from Team Rocket”

Douglas Stuart “Plague Doctor”
Abby Sallee “Graduated Cylinder”
Ampofo Darko “Zoom Outfit”
Justin Kirby “Lex Luther”

Megan Qualls “Mary Poppins”
Ryker Hill “JoJo Character”
Kerani Davidson “Ninja Turtle”
Erin Drufva “Totoro”
Avery Blockmon & Kiman Park “Men in Black”

Sam Peay “Dead Person”
Zane Vickery “Han Solo”
Maggie Powell, Sarah Hirschbeck & Bailey Eberle “H2O”

Eleanor Page “James from Team Rocket”

Nia Parker & Elizabeth O’Connell “Bring it on”

Justin Burroughs “Cowboy”

Brantley Group Published in Macromolecules

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The Brantley Group published their work “Exploring Combinatorial Approaches to Polymer Diversification” in Macromolecules. 

Diversity-oriented strategies can facilitate the rapid exploration of chemical space during small-molecule synthesis, but similar approaches are underutilized for macromolecular substrates. Expanding the repertoire of soft material manipulations to accommodate iterative diversifications could enable the design of bespoke polymers with a range of novel structures and properties.

“To explore this concept, we chose to leverage the efficiency of Suzuki–Miyaura cross-coupling to rapidly access an array of functionalized polystyrene surrogates from a readily accessible polystyrene-p-pinacol boronic ester,” Brain Jacobs, postdoc, said. “A variety of C(sp2) electrophiles efficiently coupled with our model polymer (51–99% functionalization) in moderate-to-good yields (44–96%). “

Optimized coupling reactions afforded products with minimal changes in overall dispersity (as determined by gel permeation chromatography), which suggested that the desired coupling occurred with good fidelity. “Select products were subjected to further modifications (e.g., Wittig olefination, reduction, imine condensation) to showcase the diverse array of reactivities that can be accessed using our strategy.” Jacobs said. 

Kilbey’s Research Leadership with ORE

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Mike Kilbey wraps up a year of research leadership at the UT, Knoxville, serving as chair of the Research Council of Faculty Senate and as a Faculty Fellow for Strategic Research Initiatives in the Office of Research and Engagement.

The Research Council works to promote excellence in research, scholarship, and creative activity, and provides counsel to the university’s research administration on matters that effect research.

The role of a Faculty Fellow is to assist the Associate Vice Chancellor for Strategic Research Initiatives and their team in efforts to strategically position and enhance competitiveness for large, multidisciplinary research funding.

“It was exciting to see the diversity of scholarly work that is ongoing at UT, to connect with faculty and research leaders from across the university, and to be engaged at a time when dynamic changes that impact the research landscape of the university are taking place,” Kilbey said.

Best Group Published in Chemistry and Physics of Lipids

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The Best Group’s article titled “Metabolic labeling of glycerophospholipids via clickable analogs derivatized at the lipid headgroup” was published in Chemistry and Physics of Lipids.

Metabolic labeling, in which substrate analogs containing diminutive tags can infiltrate biosynthetic pathways and generate labeled products in cells, has led to dramatic advancements in the means by which complex biomolecules can be detected and biological processes can be elucidated.

Within this realm, metabolic labeling of lipid products, particularly in a manner that is headgroup-specific, brings about a number of technical challenges including the complexity of lipid metabolic pathways as well as the simplicity of biosynthetic precursors to headgroup functionality. As such, only a handful of strategies for metabolic labeling of lipids have thus far been reported. However, these approaches provide enticing examples of how strategic modifications to substrate structures, particularly by introducing clickable moieties, can enable the hijacking of lipid biosynthesis.

Furthermore, early work in this field has led to an explosion in diverse applications by which these techniques have been exploited to answer key biological questions or detect and track various lipid-containing biological entities. In this article, the group reviews these efforts and emphasize recent advancements in the development and application of lipid metabolic labeling strategies.

Hazari Celebrates NCW With His 30th Annual “Magic of Chemistry Show”

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National Chemistry Week (NCW) is a community-based program of the American Chemical Society (ACS). This annual program unites ACS local sections, student chapters, technical divisions, businesses, schools, and individuals in communicating the importance of chemistry to our quality of life. NCW occurs annually during the third week of October.

The mission of NCW is to reach the public, particularly elementary and secondary school children, with positive messages about chemistry to:

  • Make a positive change in the public’s impression of chemistry;
  • Promote a mechanism for effectively mobilizing ACS local sections; and
  • Motivate the ACS membership through local section activities.

NCW 2020, October 18–24
Topic: Glues and Adhesives
Theme: Sticking with Chemistry

Hazari Celebrated NCW With His 30th Annual “Magic of Chemistry Show.”

Hazari is a retired UT chemistry professor has spent the past 30 years putting on science shows for audiences all over East Tennessee.

Heberle Lab’s Latest Achievements

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Research in the Heberle Lab is aimed at elucidating the structure and function of biological membranes, with a focus on the plasma membrane.

Fred A. Heberle is coauthor of the recently published book Characterization of Biological Membranes. This book explores the high importance  of membranes in the fields of biology, pharmaceutical chemistry and medicine, since much of what happens in a cell or in a virus involves biological membranes. This book is an excellent introduction to the area, which explains how modern analytical methods can be applied to study biological membranes and membrane proteins and the bioprocesses they are involved to.

Heberle was also awarded $1.7M from the National Institutes of Health (NIH) for The Research Project (R01). The R01 is the original and historically oldest grant mechanism used by NIH. The R01 provides support for health-related research and development based on the mission of the NIH. The Heberle Lab aims to extend membrane studies through an unprecedented integration of lipidomics, biophysical experiments, cryogenic transmission electron microscopy (cryoEM), and advanced molecular simulations, to test their central hypothesis that compositionally asymmetric membranes have unique biophysical properties resulting from robust coupling between lateral and transverse membrane organization. 

The Heberle Lab had a journal cover on Nanoscale for their work on “Transverse lipid organization dictates bending fluctuations in model plasma membranes.” 

The Heberle Lab published their research “Direct label-free imaging of nanodomains in biomimetic and biological membranes by cryogenic electron microscopy” in Proceedings of the National Academy of Sciences of the USA. They worked with a collaborative team to capture the first direct images of tiny cell membrane domains known as lipid rafts. The images were published as a journal cover in PNAS. 

PNAS also published the Heberle Lab’s collaborative research “How cholesterol stiffens unsaturated lipid membranes.”  Their observations that cholesterol causes local stiffening in DOPC membranes indicate that a reassessment of existing concepts is necessary. These findings have far-reaching implications in understanding cholesterol’s role in biology and its applications in bioengineering and drug design.

Xue Group’s Recent Research

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The Xue group has published multiple papers this year. This group’s research focuses on three areas: spectroscopic studies of molecular magnetism, synthesis and characterization of transition metal complexes, and the development of new chemical analyses. 

 Inorganic Chemistry published their work “Inter-Kramers Transitions and Spin–Phonon Couplings in a Lanthanide-Based Single-Molecule Magnet.” Spin–phonon coupling plays a critical role in magnetic relaxation in single-molecule magnets (SMMs) and molecular qubits. This research shows spin–phonon couplings between IR-active phonons in a lanthanide molecular complex and Kramers doublets (from the crystal field). This study unveils and measures the spin–phonon couplings in a typical lanthanide complex and throw light on the origin of the spin–phonon entanglement.

Chinese Journal of Inorganic Chemistry published the group’s work on “Direct Observation of Magnetic Transitions in a Nickel(II) Complex with Large Anisotropy.” 

Chemosphere published their work “Sustained Release of Persulfate from Inert Inorganic Materials for Groundwater Remediation.” This work demonstrates the potential feasibility of sustained persulfate release from inert matrices for groundwater treatment.

They also have an invited review for the Comprehensive Coordination III  on Tantalum in press. 

Campagna Gives Talk for Harvard’s MSI Seminar Series

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The Microbial Sciences Initiative (MSI) at Harvard University is an interdisciplinary science program aimed at a comprehensive understanding of the richest biological reservoir of the planet, the microbial world.

Shawn Campagna presented a talk for this series titled “Using Metabolomics to Understand the Function of Environmentally Relevant Microbial Consortia.”

 

Calhoun Lab Featured Cover in J. Phys. Chem. C

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The Calhoun Lab was published in the Journal of Physical Chemistry C for their research “Leaving the Limits of Linearity for Light Microscopy” and it is a perspective on the recent advances in the field of nonlinear microscopy. This article is also the featured cover for the November 12, 2020 issue.

Graduate student authors include Marea Blake and Brandon Colon.  Blake is currently pursuing her Ph.D. in Chemistry at the University of Tennessee, Knoxville. Her current research focuses on probing small molecule-membrane interactions in living cells using nonlinear techniques such as second harmonic generation and two-photon fluorescence.

Colon received his B.S. degree (2016) in Chemistry from the University of West Florida in Pensacola, FL. He is a doctoral student at the University of Tennessee under the tutelage of Prof. Tessa Calhoun. He has been investigating the use of total internal reflection illumination geometries to apply nonlinear microscopy techniques to microfluidic samples.

In this paper, the group highlights recent developments within the past couple of years pertaining to how nonlinear microscopy methods such as transient absorption, 2D nonlinear microscopy, second order processes, and quantum microscopy are being implemented to probe different timescales, access information on interfaces and illuminate samples with novel excitation schemes. 

“Our group actually uses a few of these methods (such as TAM, SHG and TIR geometry excitation) in our lab so it was really exciting getting to portray that in this perspective and explore the directions they can grow,” Blake said.

Best Group’s Recent Work

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Recent work in the Best Group has culminated in the development of stimuli-responsive liposomes for drug delivery designed to release therapeutic cargo when they come into contact with diseased cells, specifically based on overexpressed enzymes and reactive oxygen species. “These smart liposomes show strong prospects for advancing drug delivery by targeting therapeutics directly to the site of the disease,” Jinchao Lou, graduate student in the Best Group, said.

Liposomes are effective nanocarriers for drug delivery due to their ability to encapsulate and deliver a wide variety of therapeutic cargo to cells. Nevertheless, liposome delivery would be improved by enhancing the ability to control the release of contents within diseased cells. Toward this end, stimuli-responsive liposomes, in which the drug carrier decomposes when it comes in contact with conditions associated with disease, are of great interest for enhancing drug potency while minimizing side effects.

While various stimuli have been explored for triggering liposome release, both enzymes and reactive oxygen species (ROS) provide excellent targets due to their key roles in biology and overabundance in diseased cells. In two separate papers, the Best Group presented a general approach to enzyme‐responsive liposomes exploiting targets that are commonly aberrant in disease, including esterases, phosphatases, and β‐galactosidases (Chem. Eur. J. 2020, 26, 8597-8607), as well as an ROS-responsive liposomal delivery platform (Bioconjugate Chem. 2020, 31, 2220-2230).

In both of the cases, responsive lipids designed to target each stimulus were designed and synthesized bearing a responsive headgroup attached via a self‐immolating linker to a non‐bilayer lipid scaffold. In this way, stimulus addition triggers chemical lipid decomposition in a manner that disrupts membrane integrity and releases contents. Release properties were fully characterized by fluorescence-based dye leakage assays, dynamic light scattering and electron microscopy, among other techniques.

Due to their recent works in this field, the Best group was also invited to write a review describing advances in the design of stimuli-responsive liposome strategies for drug delivery with an eye towards emerging trends in the field (Chem. Phys. Lipids. In Press. DOI 10.1016/j.chemphyslip.2020.104966). Smart liposomes show strong prospects for advancing drug delivery by targeting drugs directly to the site of the disease.