Tag Archive for Chemistry

Faculty Teach Local Girls about Science

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The Green Street Teaching and Learning Center hosted a Girls in Science Camp Aug. 3-7. Wesleyan faculty members Ruth Johnson, assistant professor of biology (pictured third from left); Erika Taylor, assistant professor of chemistry, assistant professor of environmental studies (pictured at far right); Chris Othon, assistant professor of physics (pictured at left), along with three undergraduate students, worked with the campers on various experiments. Sara MacSorley, director of the GSTLC (second from left), coordinated the activities.

Johnson led the campers on a bug hunt through Wesleyan’s West College Courtyard garden. There, the girls observed insects while considering insect diets and insect life-cycles. The girls also learned about the life-cycle of the fruit fly and set up an experiment to test the effects of feeding flies a high-sugar diet (this negatively affects the fly life-cycle, and is akin to inducing Type II Diabetes). Johnson also taught the campers about genetic variations (mutations) that affected wing and bristle development.

“Learning about these phenotypes served as an intro to genetics, genes and proteins,” Johnson said.

Johnson also taught the girls about microscopy. After a short presentation on how a variety of biological objects appear when viewed with high magnification, the girls viewed and captured images of the fly pupal eye with a fluorescent microscope. The girls also viewed a variety of mutant adult fly eyes with dissecting microscopes and, to build their skills in observation, built 3D models of these with modeling clay.
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Students Share Summer Research at Poster Session

On July 30, Wesleyan’s Summer Research Poster Session took place at Exley Science Center. More than 110 undergraduate research fellows from Math and Computer Sciences, Astronomy, Physics, Chemistry, Molecular Biology and Biochemistry, Biology, Earth and Environmental Sciences, the Quantitative Analysis Center, and Psychology presented research at the event. (Photos by Laurie Kenney)

Aidan Bardos ’17 presented her research titled "The Effects of Nutrition on the Immune Response of Wooly Bear Caterpillars Infected by Parasitoid Wasps." Bardos' faculty advisor is Michael Singer, associate professor of biology and environmental studies.

Aidan Bardos ’17 presented her research titled “The Effects of Nutrition on the Immune Response of Wooly Bear Caterpillars Infected by Parasitoid Wasps.” Bardos’ faculty advisor is Michael Singer, associate professor of biology and associate professor of environmental studies.

A poster titled "Immunohistochemical Analysis of Status Epilepticus Mice Treated with Striatal-Enriched Tyrosine Phosphatase Inhibitor" was presented by Matt Pelton ’17. His advisor is Janice Naegele, professor of biology, professor of neuroscience and behavior.

A poster titled “Immunohistochemical Analysis of Status Epilepticus Mice Treated with Striatal-Enriched Tyrosine Phosphatase Inhibitor” was presented by Matt Pelton ’17. His advisor is Janice Naegele, professor of biology, professor of neuroscience and behavior.

Uchendu ’17 Researches Production of Biofuels as McNair Scholar

Stacy Uchendu ‘17 is researching second generation biofuels with Erika Taylor, assistant professor of chemistry and environmental studies, as a McNair Scholar.

Science in Society major Stacy Uchendu ‘17 is researching second generation biofuels as a McNair Scholar.

In this News @ Wesleyan story, we talk with Stacy Uchendu from the Class of 2017. Uchendu is participating in Wesleyan’s Ronald E. McNair Post Program, which assists students from underrepresented groups in preparing for, entering and progressing successfully through post-graduate education.

Q: Stacy, where are you from and what is your major?

A: I’m from Houston, Texas, and my major is Science in Society with concentrations in chemistry and religion.

Q: When did you become a part of the McNair Program? Why did you decide to participate?

A: McNair offers a wonderful opportunity to do paid research over the summer and during the academic school year.

NIH Grant will Support Taylor’s Drug Treatment Research

Erika Taylor

Erika Taylor

On June 15, Erika Taylor, assistant professor of chemistry, assistant professor of environmental studies, received a grant from the National Institute of Allergy and Infectious Diseases (part of the National Institutes of Health) to support her research on “Inhibition of (the enzyme) HeptosyltransferaseI for the treatment of Gram-negative bacterial infection.” Gram-Negative bacteria include things like E. coli, Salmonella, and V. cholerae (the cause of Cholera) that are common causes of food-bourne illnesses.

The grant, worth $492,000 will enable her to engage multiple graduate and undergraduate students in the proposed work through June 2018. Preliminary results for this project were obtained with the help of graduate student Joy Cote and Dan Czyzyk PhD ’15; and undergraduates Zarek Siegel ’16, Keonmin Hwang ’16, Noreen Nkosana BA ’11, MA ’13, and several others.

The current widespread use and misuse of antimicrobials has led to the emergence of bacterial resistance to many commonly used antibiotics, necessitating development of new drug targets. Lipopolysaccharides, a major constituent of the Gram-negative bacterial outer membrane, important for cell motility, intestinal colonization and bacterial biofilms formation, contribute substantively to antibiotic resistance by hampering antibiotic uptake. Inhibiting the synthesis of bacterial lipopolysaccharides results in bacteria that are unable to form biofilms and are more susceptible to antimicrobials.

The LPS heptosyltransferase enzymes investigated as part of this proposal are therefore potential targets for the inhibition of bacterial biofilm formation and the development of therapeutic agents.

“Every morning when you wake, you have a bacterial biofilm on your teeth,” Taylor explained. “Also, when you see/feel slime on a rock at the shore that too is likely from a bacterial biofilm (so long as it isn’t being caused by algae).”

Bacteria grow in biofilms to help enable survival under harsh conditions (including things like drying out, being exposed to highly acidic environments as happens in our mouths; biofilms also help bacteria resist UV-radiation and antibiotic treatments).

The project is intended to lead to the development of new antimicrobials for the treatment of Gram-negative bacterial infections. The long-term goal of this work is the development of new drugs for the treatment of these infections, Taylor said. This work also could help in the prevention of secondary infections transmitted in hospitals because of the prevention of bacterial biofilms on things like catheters.

Taylor’s Papers Published in Molecular Biosciences, Biochemistry Journals

Erika Taylor

Erika Taylor

Erika Taylor, assistant professor of chemistry, assistant professor of environmental studies, has co-authored a paper published in FEBS Letters, an international journal established for the rapid publication of final short reports in the fields of molecular biosciences.

The paper, which is an expansion of her lab’s work on the enzyme Heptosyltransferase I, is titled “Cloning and Characterization of the Escherichia coli Heptosyltransferase III: Exploring Substrate Specificity in Lipopolysaccharide Core Biosynthesis,” The paper is co-authored by her former graduate student Jagadesh Mudapaka. FEBS Letters is published by Elsevier on behalf of the Federation of European Biochemical Societies.

Taylor also is the co-author of “Improving Alternate Lignin Catabolite Utilization of LigAB from Sphingobium sp. strain SYK-6 through Site Directed Mutagenesis,” published in Process Biochemistry, June 2015. The work in this paper describes molecular engineering of the enzyme LigAB to be better able to metabolize compounds derived from Lignin. Co-authors include Kevin Barry, PhD ’15; Erin Cohn ’15 and Abraham Ngu ’13.

Taylor presented her research “Thoughts about Adenosine: Efforts in Drug Discovery of Nucleoside Utilizing Enzymes” at the Gordon Research Conference: Nucleosides, Nucleotides and Oligonucleotides in July. Her talk described the work she is performing to help in drug discovery for two enzymes from E. coli, Heptosyltransferase I and the TrmD tRNA methyltransferase, and one human enzyme, p300 histone acetyl transferase.

“Our work in these systems involves computational modeling of interactions between small molecules and the enzymes, to help design new compounds with medical applications,” Taylor explained.

Grad Student Ranasinghe Speaks on Computational Chemistry

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Duminda Ranasinghe, a Ph.D. candidate in Chemistry, spoke April 16 in Exley in the fourth event of the Graduate Student Speaker Series. (Photos by Hannah Norman ’16.)

Ranasinghe gave a talk titled “Computational Chemistry: Chemistry Without Chemical.”

Ranasinghe gave a talk titled “Computational Chemistry: Chemistry Without Chemical.”

Computational chemistry uses quantum mechanics to predict reactions and molecular properties.

Computational chemistry uses quantum mechanics to predict reactions and molecular properties.

Over the past decade, computational chemistry has become popular with chemists as a tool to explore reactions and molecules. At Wesleyan, researchers are making reliable computational methods, which are accurate and faster than what is currently available.

Over the past decade, computational chemistry has become popular with chemists as a tool to explore reactions and molecules. At Wesleyan, researchers are making reliable computational methods, which are accurate and faster than what is currently available.

Othon, Taylor Students Published in Physical Chemistry Letters

Christina Othon and Erika Taylor, along with physics graduate student Nimesh Shukla, Lee Chen ’15, Inha Cho ’15 and Erin Cohn ’15, are the co-authors of a paper titled “Sucralose Destabilization of Protein Structure” published in The Journal of Physical Chemistry Letters, March 2015. Othon is assistant professor of physics and was PI on the paper. Taylor is assistant professor of chemistry, assistant professor of environmental studies.

Sucralose is a commonly employed artificial sweetener that behaves very differently than its natural disaccharide counterpart, sucrose, in terms of its interaction with biomolecules. This research suggests that people may need to think about the impact of sucralose (a.k.a. Splenda) on their proteins.

Watch Othon explain associated research in this video. She speaks around the 34 minute mark.

Women in Science Gather for Tea Reception, Female Scientists Discussion

#THISISWHY

About 30 Wesleyan students and faculty gathered for a Wesleyan Women in Science (WesWIS) Tea Reception Feb. 19 at the Wasch Center. Women in Science is a student group composed of undergraduates, post-docs, staff and faculty dedicated to issues affecting women in science. The group is open to all majors and genders.

During the gathering, guest speaker Michelle Francl, professor of chemistry on the Clowes Fund for Science and Public Policy at Bryn Mawr College, spoke to the group about physicist and chemist Marie Curie, the first woman to win a Nobel Prize.

Francl handed out copies of her commentary titled “Sex and the Citadel of Science,” which was published in the August 2011 edition of Nature Chemistry, and included a copy of the journal’s cover — a portrait of Marie Curie’s face created from photographs of 200 women scientists (including Francl’s). “I’m actually in here twice. There’s another picture in here of my mother, who also was a chemist, holding me as an infant,” she said.

“I love how energized the room felt at the WesWIS tea,” said Meredith Hughes, assistant professor of astronomy. “It was exciting to have Dr. Francl there, and also to get so many energetic Wesleyan women scientists all in one place!”

WesWIS Steering Committee members Alex Irace ’15 and and Maya Lopez-Ichikawa ’18 spoke about the group and introduced Professor Francl. Francl also delivered two workshops on contemplative pedagogy during her time at Wesleyan.

Photos of the event are below:

Wesleyan Women in Science Tea Reception, Feb. 19, 2015.

Northrop Co-Authors Paper with Middletown Student

Brian Northrop, assistant professor of chemistry, is the co-author of several new papers including:

Preparation and Analysis of Cyclodextrin-Based Metal-Organic Frameworks: Laboratory Experiments Adaptable for High School through Advanced Undergraduate Students,” published in Journal of Chemical Education 92, pages 368-372, 2015. Samantha Angle, a Middletown High School student working in Northrop’s lab, co-authored the paper. (See cover at left.)

Rational Synthesis of Bis(hexyloxy)-Tetra(hydroxy)-Triphenylenes and their Derivatives,” published in RSC Advances 4, pages 38,281-392 in 2014;

Vibrational Properties of Boroxine Anhydride and Boronate Ester Materials: Model Systems for the Diagnostic Characterization of Covalent Organic Frameworks,” published in Chemistry of Materials 26, pages 3,781-95 in 2014;

And “Allyl-Functionalized Dioxynaphthalene[38]Crown-10 Macrocycles: Synthesis, Self-Assembly, and Thiol-Ene Functionalization,” published in Chemistry—A European Journal 20, pages 999-1,009 in 2014.

Novick’s Papers Focus on van der Walls Complex, Trifluoroanisole Water

Stewart Novick

Stewart Novick

Stewart Novick, chair and professor of chemistry, is the co-author of several papers published in 2014. They include:

“The microwave spectra and structure of the argon-cyclopentanone and neon-cyclopentanone van der Waals complexes,” published in the Journal of Physical Chemistry A 118, pages 856-861;

“The shape of trifluoromethoxybenzene,” published in the Journal of Molecular Spectroscopy 297, pages 32-34;

“Fluorination effects on the shapes of complexes of water with ethers: a rotational study of trifluoroanisole-water,” published in the Journal of Physical Chemistry, A 118, pages 1,047-51;

“Measurement of the J = 1 – 0 pure rotational transition in excited vibrational states of X 1Σ Thorium (II) Oxide,” Journal of Molecular Spectroscopy, 302, 1-2;

And “H2 AgCl: a spectroscopic study of a dihydrogen (metal halide complexes with hydrogen) complex,” published in the Journal of Physical Chemistry, 141, 114306.

Frisch Published in Multiple Chemistry Journals, Publications

Michael Frisch

Michael Frisch

Michael Frisch, research professor of in chemistry, is the co-author of many articles published in 2014.

They include: “Analytical harmonic vibrational frequencies for the green fluorescent protein computed with ONIOM: Chromophore mode character and its response to environment,” published in the Journal of Chemical Theory and Computation, 10, pages 751-766;

“Quantum calculations in solution for large to very large molecules: A new linear scaling QM/continuum approach,” published in the Journal of Physical Chemical Letters, 5, pages 953-958;

“Density of states guided Møller-Plesset perturbation theory,” published in the Journal of Chemical Theory and Computation, 10, pages 1,910-14;

“Practical auxiliary basis implementation of Rung 3.5 functionals,” published in the Journal of Physical Chemistry, 141, 034103;

“A computational protocol for modeling thermochromic molecular crystals: salicylidene aniline as a case study,” published in the Journal of Chemical Theory and Computation, 10, pages 5,577-85;

“Assessment of low-scaling approximations to the equation of motion coupled-cluster singles and doubles equations,” the Journal of Physical Chemistry, 141, 164116;

“Quantum, classical and hybrid QM/MM calculations in solution: General implementation of the ddCOSMO linear scaling strategy,” published in the Journal of Physical Chemistry, 141, 184108;

“Ab initio non-relativistic spin dynamics,” published in the Journal of Physical Chemistry, 141, 214111;

And “How far do electrons delocalize?,” published in the Journal of Physical Chemistry. 141, 144104.

Paper by Taylor, Students Show How Enzymes Break down Lignin

Erika Taylor, assistant professor of chemistry, assistant professor of environmental studies, is the author of a paper “Exploring Allosteric Activation of LigAB from Sphingobium sp. strain SYK-6 through Kinetics, Mutagenesis and Computational Studies,” published in Archives of Biochemistry and Biophysics, Vol, 567, pages 35-45, February 2015.

Co-authors include graduate students Kevin Barry and Joy Cote; Erin Cohn ’15, Abraham Ngu ’13 and former graduate student Jason Gerbino.

Development of renewable alternatives for petroleum derived fuels and chemicals is of increasing importance because of limits on the amount of fossil fuels that are available on the planet. In an effort to improve the utilization of lingo-cellulosic biomass sources (which includes switchgrasses, trees and other terrestrial plants) for the production of these chemicals, Taylor and her students have been working to enhance the understanding of how Lignin is broken down in nature (by environmental fungi and bacteria). As part of this work, they study an enzyme called LigAB from Sphingobium sp. strain SYK-6.

In a recent study, Taylor’s group showed that this enzyme works faster in the presence of vanillin, a molecule that is produced in large quantities as Lignin is depolymerized (which also is the primary ingredient in vanilla extract).

“The activation of LigAB is exciting because the enzymes that break down vanillin show that an organism can more efficiently metabolize all of the compounds — or get energy from the abundant molecule more quickly. This is the first time that an enzyme like LigAB has been shown to be responsive to other metabolically linked molecules, and it suggests that the flux of compounds through this pathway may be more complicated and interesting that initially predicted,” Taylor said.

Now, the group is interested in figuring out exactly how this activation works and also if there are any relatives of LigAB that exhibit similar behavior.