Tag Archive for Chemistry

Faculty Spotlight: Michelle Personick

Michelle Personick joined the faculty this fall, and is teaching courses in Chemistry of Materials and Nanomaterials and an Integrated Chemistry Lab. (Photo by Olivia Drake)

Michelle Personick, assistant professor of chemistry, assistant professor of integrative sciences, is an advocate for Wesleyan Women in Science (WesWIS). “The more women (and underrepresented minorities) who pursue careers in the sciences, the more younger female and underrepresented students will be able to imagine themselves in those roles, and the sciences will begin to diversify,” she said. (Photo by Olivia Drake)

In this Q&A, we speak with Michelle Personick, assistant professor of chemistry, assistant professor of integrative sciences. Personick, who joined the faculty at Wesleyan in 2015, is interested in developing tailored metal nanomaterials that improve the clean production of energy and enable the efficient use of energy resources. Her work has recently been published in the journals Particle and Particle Systems Characterization and American Chemical Society Catalysis.

Q: Professor Personick, how would you describe your main research interests?

A: The main research areas in my group are controlling the shape and composition of noble metal nanocrystals, and exploring the use of these nanoparticles as catalysts to improve the efficiency and selectivity of reactions that are important in chemical industry and in energy production.

When she's not teaching or working in the lab, Michelle Personick, at right, rows crew with the Riverfront Recapture masters racing team in Hartford.

When she’s not teaching or working in the lab, Michelle Personick, at right, rows with the Riverfront Recapture masters racing team in Hartford, Conn.

Q: When did you develop an interest in chemistry?

A: I’ve always been interested in science in general, but it was more a broader interest than a specific focus on chemistry. There was actually a period of time in high school when I wanted to be a particle physicist. I chose chemistry after writing an essay about a cool new light-controlled nanoparticle cancer treatment for a class my senior year in high school.

Q: What attracted you to Wesleyan and how has your experience been here over the last couple years?

A: I had a really positive small liberal arts college experience at Middlebury, where most of my professors knew who I was and cared about how I was doing in their class. Once I decided I wanted to be a professor, I knew that was the type of environment I wanted. In the different courses I’ve taught in my first two years, I’ve found the atmosphere at Wesleyan to be well-matched to pursuing that kind of teaching philosophy. What attracted me to Wesleyan specifically are the unique research opportunities that come out of having a small, but strong, graduate program in addition to being a top-tier undergraduate institution. The advanced research instrumentation here at Wesleyan, such as the electron microscopy facility, is also crucial to our ability to successfully carry out our research. I’d always wanted to work primarily with undergraduates once I set up my own research lab, but having even just two graduate students in that lab as well makes an enormous difference in the level of research I’m able to carry out. In turn, that creates an environment in which the very talented undergraduates I’ve had in my group so far have the opportunity to work on independent projects that get published in peer-reviewed journals and that are well-received by other scientists at major conferences. It’s been very rewarding over the last two years to get our lab up and running and to begin to see the results of the hard work put in by all of my research students, undergraduate and graduate.

Plasma Bubble, Stem Cell Images Win Scientific Imaging Contest

This summer, Wesleyan hosted the second annual Wesleyan Scientific Imaging Contest, which recognizes student-submitted images from experiments or simulations done with a Wesleyan faculty member that are scientifically intriguing as well as aesthetically pleasing. This year, 33 images were submitted from six departments.

The entries were judged based on the quality of the image and the explanation of the underlying science.  The images were judged by a panel of four faculty members: Steven Devoto, professor of biology, professor of neuroscience and behavior; Ruth Johnson, assistant professor of biology, assistant professor of integrative sciences; Brian Northrop, assistant professor of chemistry, assistant professor of integrative sciences; and Candice Etson, assistant professor of physics.

The first-place winner received a $200 prize; the second-place winner received $100; and the third-place winner received $50. Prizes were funded by the Office of Academic Affairs.

The three winning images are shown below, along with scientific descriptions, written by the students.

Yonathan Gomez '18 won first place with his image, "Jumping" Drop. The drop is an expanding partially-ionized plasma created underwater by a pulsed Nd:YAG laser, which pushes upwards on the surface of the water. As the plasma bubble expands, it disrupts the surface from below, which launches a water drop upward. The water drop shown has a diameter of approximately 2mm. The image was taken at 1/2,000 frames per second.

Yonathan Gomez ’18 won first place with his image, “Jumping” Drop. The drop is an expanding partially-ionized plasma created underwater by a pulsed Nd:YAG laser, which pushes upwards on the surface of the water. As the plasma bubble expands, it disrupts the surface from below, which launches a water drop upward. The water drop shown has a diameter of approximately 2mm. The image was taken at 1/2,000 of a second.

Research Paper by Personick, King Published in ‘Particle’ Journal

Michelle Personick, assistant professor of chemistry, and her graduate student Melissa King, are co-authors of a paper titled “Bimetallic Nanoparticles with Exotic Facet Structures via Iodide-Assisted Reduction of Palladium,” published in the journal Particle and Particle Systems Characterization, Vol. 34, Issue 5, in May 2017. The research was featured on the inside front cover of the issue.

In this study, Personick and King explain how gold–palladium tetradecapods (14-pointed nanoparticles) with an unusual combination of both well-defined concave and convex facets can be synthesized by introducing dilute concentrations of iodide during nanoparticle growth. Iodide directs the formation of the tetradecapods by increasing the rate of palladium ion reduction, which is a new role for this shape-controlling additive.

This article also was recently highlighted in Advanced Science News.

Mukerji, Oliver Co-Author Study in PNAS on Basic Cell Function

In this illustration, SecA is shown in light gray and the SecYEG complex is in dark gray. The rainbow colored portion of SecA is the two helix finger. n cyan is a model of the hairpin.

In this illustration, the hairpin is highlighted in cyan. The hairpin is formed by the initiator part of a protein.

All cells — bacterial or human — secrete up to 10 or 20 percent of the proteins that they make. Human secreted proteins, for example, include components of serum, hormones, growth factors that promote cell development during embryogenesis and tissue remodeling, and proteins that provide the basis for immune cell signaling during infection or when fighting cancer.

The secretion process, however, isn’t an easy feat for cells, as they need to move the proteins across a membrane through a channel. Transport requires the formation of a hairpin, formed by an initiator protein.

In a recent study, Don Oliver, the Daniel Ayres Professor of Biology, professor of molecular biology and biochemistry, and Ishita Mukerji, the Fisk Professor of Natural Science, professor of molecular biology and biochemistry, explain the importance of where and why hairpins form and how they help proteins move across the cell.

The study, titled “Alignment of the protein substrate hairpin along the SecA two-helix finger primes protein transport in Escherichia coli,” brings together key areas of membrane biochemistry, structural biology and molecular biophysics, and has innovative applications of molecular genetics and fluorescence spectroscopy. It was published in the Aug. 7 issue of Proceedings of the National Academy of Sciences (PNAS).

Personick Awarded Grant from American Chemical Society Petroleum Research Fund

Michelle Personick joined the faculty this fall, and is teaching courses in Chemistry of Materials and Nanomaterials and an Integrated Chemistry Lab. (Photo by Olivia Drake)

During the fall 2017 semester, Michelle Personick will teach Nanomaterials Lab and a chemistry symposia.

Michelle Personick, assistant professor of chemistry, received a two-year doctoral new investigator grant from the American Chemical Society Petroleum Research Fund (ACS PRF) to synthesize and test new metal nanomaterials designed to make industrial chemical processes more energy efficient. Her study, titled “Tailored Bimetallic Catalysts with Highly Stepped Facets for Selective and Energy-Efficient Epoxidation and Hydrogenation Reactions,” will be supported for two years with a $110,000 award.

“Global energy consumption is steadily increasing, and the chemical industry is the second largest consumer of delivered energy,” Personick said. “The chemical industry is unique in that it uses energy resources, such as petroleum and natural gas, both as fuels to heat reactors and as starting precursors or ‘feedstocks’ for the production of chemicals and materials.”

As demand for products of the chemical industry—such as pharmaceuticals, plastics, and specialty chemicals—increases, the consumption of energy in this sector increases dramatically. Most industrial chemical processes rely on a catalyst—a substance that increases the rate of a chemical reaction but is not used up in the reaction.

The goal of the funded research is to understand how tuning the shape and composition of metal nanoparticles changes their performance as catalysts in industrially important chemical transformations. The long-term objective is to apply this fundamental understanding to the design of nanoscale catalysts which make industrial chemical reactions more energy efficient and sustainable by (1) enabling the reactions to take place at lower temperatures and/or (2) eliminating the production of unwanted byproducts, such as carbon dioxide.

Students Inducted into Honor Society, Win Awards At American Society for Biochemistry and Molecular Biology

Julianne Riggs in Chicago last month, where she attended the American Society for Biochemistry and Molecular Biology meeting.

Julianne Riggs ’17 in Chicago last month, where she attended the American Society for Biochemistry and Molecular Biology meeting.

Five Wesleyan seniors were inducted into the American Society for Biochemistry and Molecular Biology honor society at the ASBMB annual meeting in Chicago, April 22-26. They are: Jennifer Cascino ’17, Kaileen Fei ’17, Julianne Riggs ’17, Rachel Savage ’17 and Stacy Uchendu ’17.

The ASBMB Honor Society recognizes exceptional undergraduate juniors and seniors who are pursuing a degree in the molecular life sciences for their scholarly achievement, research accomplishments, and outreach activities. The mission of the society is to advance the science of biochemistry and molecular biology through organization of scientific meetings, advocacy for funding of basic research and education, support of science education at all levels, promotion of the diversity of individuals entering the scientific workforce, and publication of a number of scientific and educational journals, including the Journal of Biological Chemistry and the Journal of Lipid Research.

Bios of all the inductees, in alphabetical order, can be found here.

Riggs attended the meeting, where she took part in the induction ceremony and presented her research.

“Overall, it was a great experience. I got to present in the undergraduate poster competition and won honorable mention for best chromatin and gene expression poster. I also presented my poster to the general meeting,” she said. “It was a huge conference and there was so much going on. It was great to talk to people of all levels of science, get their perspectives on what it takes to be a scientist, and hear them passionately discuss their research projects. It was also wonderful to talk to people who were researching similar topics to mine, and get their advice and validation on my work.”

In addition, two students, Christine Little ’18 and Cody Hecht ’18, received ASBMB research awards. The $1,000 awards will support their research over the summer.

Faculty, Students, Alumnus Co-Author Paper in Biochemistry Journal

Wesleyan co-authors published a paper titled “The Stories Tryptophans Tell: Exploring Protein Dynamics of Heptosyltransferase I from Escherichia coli” in the January 2017 issue of Biochemistry.

The co-authors include chemistry graduate student Joy Cote; alumni Zarek Siegel ’16 and Daniel Czyzyk, PhD ’15; and faculty Erika Taylor, associate professor of chemistry; Ishita Mukerji, the Fisk Professor of Natural Science, professor of molecular biology and biochemistry.

Their paper investigates the intrinsic properties of Tryptophan amino acids found within the protein, Heptosyltransferase I, to understand the ways this protein moves during catalysis. Understanding the movement of this protein is an important step in developing its inhibitors.

When this protein is inactive, either because it was genetically altered or inhibited, hydrophobic antibiotics become more effective, so inhibitors could be useful in reactivating antibiotics that are current not effective against these bacteria.

While it is popularly believed that inhibiting a protein requires a compound to compete with the substrate, their paper argues that instead one can design a inhibitor to disrupt protein dynamics, preventing activity. The co-authors compare the function of this “protein dynamics disruptor” to a wedge holding open a door–once inserted, the inhibitor prevents the protein from performing its function.

Their research on Tryptophan residues also found that distant regions of the protein communicate whether or not they are binding their substrate to other regions.

“It would be like if your right hand knew that your left hand was holding a pencil just by the changes in the position of your left hand. We are currently pursuing computational studies to look for these motions via molecular dynamics experiments,” Taylor said.

Fry to Be Honored at Electrochemical Symposium in May

Albert J. Fry will be honored at a symposium for the Electrochemical Society.

Albert Fry will be honored at a symposium for the Electrochemical Society.

Albert Fry, the E.B. Nye Professor of Chemistry, Emeritus, will be honored at the Electrochemical Society National Meeting in New Orleans in May.

The symposium, aptly titled, “The 80th Birthday Trifecta in Organic Electrochemistry,” celebrates Fry, and his two colleagues, Professor Jean Lessard of Sherbrooke University and Professor Denis Peters of Indiana University, who will all be celebrating their 80th birthdays.

“Besides having carried on research in organic electrochemistry for many years, each of us has served as chair of the organic and biological electrochemistry division of the Society, and Peters and I received the Baizer Award in organic electrochemistry,” explained Fry. “Although I retired in January, I’m still carrying computational research in electrochemistry and will present a lecture on recent results of this computational work at the New Orleans meeting.”

Chemistry, Physics Students Attend Biomedical Research Conference

Contributed photo

From Nov. 9-12, two faculty members and five students from the physics and chemistry departments, attended the Annual Biomedical Research Conference for Minority Students in Tampa, Fla.

Candice Etson, assistant professor of physics, and Erika Taylor, associate professor of chemistry, were joined by McNair Scholars Luz Mendez ’17, Tatianna Pryce ’17, Stacy Uchendu ’17 and Hanna Morales ’17; and Wesleyan Mathematics and Science (WesMaSS) Scholar Helen Karimi ’19.

Students observed other research being performed around the nation by students who are members of underrepresented groups in Science, Technology, Engineering and Mathematics (STEM). In addition, the Wesleyan students presented their own research and Morales and Karimi were awarded Outstanding Poster Presentation Awards.

“Through the PIE Initiative, Wesleyan has a deliberate strategy to support underrepresented students and faculty in STEM fields by providing resources that increasing post-Wesleyan mentorship and exposure to research excellence, all of which were fulfilled through this conference,” said Antonio Farias, vice president for equity and inclusion/Title IX officer. “It cannot go without saying that without Professor Taylor’s and Professor Etson’s holistic mentorship approach, these type of opportunities for our young scholars would not be possible.”

Taylor Co-Authors Study on Knotted Protein Configurations

Erika Taylor

Erika Taylor

Erika Taylor, associate professor of chemistry, is a co-author of a paper titled, “Methyl transfer by substrate signaling from a knotted protein fold,” published in the August 2016 issue of the Nature Structural & Molecular Biology newsletter.

The paper describes the protein TrmD, an enzyme that catalyzes tRNA modification, but unlike most proteins, TrmD has an “interesting knotted configuration, which is not common,” Taylor said.

The paper demonstrates that even in proteins with knotted configurations, the internal protein movements and dynamics are important for binding, signaling and catalysis.

“This is exciting because one might expect knotted proteins to be more static in their structure due to the knot, where the amino acids wrap in on themselves, but the evidence suggests that protein dynamics are just as important in these types (knotted configurations) of proteins,” she said.

 

RNA Splicing, Student Research Discussed at Biophysics, Biological Chemistry Retreat

The Molecular Biophysics Program, the Department of Chemistry and the Department of Molecular Biology and Biochemistry hosted the 17th Annual Molecular Biophysics and Biological Chemistry Retreat on Sept. 29 at Wadsworth Mansion in Middletown.

The event included several talks by Wesleyan faculty and two student research poster presentations.

Professor Anna Pyle delivered the keynote address titled “Structural and Mechanistic Insights into RNA Splicing.” Pyle is the Howard Hughes Medical Institute Investigator and the William Edward Gilbert Professor in the Departments of Molecular, Cellular and Developmental Biology and Chemistry at Yale University. Pyle studies the structure and function of large RNA molecules and RNA remodeling enzymes. A Howard Hughes Medical Institute Investigator since 1997 and the author of more than 150 publications, she uses a diverse set of biochemical and biophysical techniques, including crystallography and chemical probing, to understand the structural complexity of RNA architecture.

Photos of the retreat are below: (Photos by Will Barr ’19 and Gabi Hurlock ’20)

Biophysics Retreat at Wadsworth Mansion Sept 29, 2016. (Photo by Gabi Hurlock)