- Speaker: Andre K. Isaacs, Associate Professor of Chemistry, College of the Holy Cross
- Seminar Title: "A Click Chemistry Approach to Nitrogen Heterocycles"
- Date & Time: Friday, September 8, 11:45 am - 12:45 pm
- Location: Druckenmiller Hall, Room 016
- Abstract: Our research interests are centered on a very reliable organic reaction - the copper catalyzed cycloaddition of sulfonyl azides and terminal alkynes (CuAAC). Differential fragmentation of the resulting 1,2,3-triazole generates ketenimines or rhodium carbenoids which readily engage with a variety of nucleophiles to gain access to heterocycles of interest to the synthetic community. We demonstrate the utility of click chemistry in the synthesis of N-Heterocycles such as indolizines, dihydroisoquinolines and beta-lactams.
- Bio: A native of Jamaica, André moved to the US to attend the College of the Holy Cross where he received his B.A. in Chemistry in 2005. As an undergraduate, he conducted research in the labs of Kevin J. Quinn focusing on the total synthesis of annonaceous acetogenins Muricatacin and Rollicosin. He received his PhD from the University of Pennsylvania in 2011 (under the guidance of Professor Jeffery D. Winkler), where he focused on the design and synthesis of novel steroid-derived inhibitors of Hedgehog-signaling, based on the alkaloid cyclopamine. He worked as a post-doctoral researcher with Professor Richmond Sarpong at the University of California, Berkeley, where he focused on the synthesis of diterpenoids and the radiolabeled insecticide chlorantraniliprole. In 2012, Andre accepted a tenure-track position at the College of the Holy Cross. In 2018, Andre was promoted to the rank of Associate Professor with tenure. In addition to teaching courses in Organic Chemistry, Andre conducts research utilizing copper-mediated organic transformations. He is one of the co-founding members of Outfront - the college's LGBTQ faculty and staff alliance and serves as faculty advisor to a number of student groups including the Caribbean African Students' Assemblage, acapella group Fools on the Hill and Club Tennis.
- Speaker: Stephanie Lee, Associate Professor of Chemistry, New York University (NYU)
- Seminar Title: "Twisted Organic Semiconductor Crystals"
- Date & Time: Friday, September 29, 1:10 - 2:10 pm (updated)
- Location: Druckenmiller Hall, Room 016
- Abstract: "Molecular crystals that twist as they grow introduce completely unexplored features to materials design. Here, we present growth-induced twists to molecular semiconductor crystals with the expectation that continually precessing crystallographic orientations can modulate interactions with photons and electrons. We have found that a variety of organic semiconductors and charge transfer complexes can be readily induced to grow from the melt as spherulites of tightly packed helicoidal fibrils. Because twisting exposes different crystallographic faces at the film/air interface, all crystal orientation-dependent properties, including absorptivity, emissivity, conductivity, solubility and reactivity, are patterned in the films. Twisting also imparts chirality to crystals, opening the possibility of repurposing centrosymmetric molecules for chiroptoelectronics."
- Bio: Stephanie Lee joined the Department of Chemistry at New York University as an associate professor in January 2021. She received a BS in chemical engineering from MIT in 2007 and a PhD in chemical engineering and materials science from Princeton University in 2012. She was a Provost’s Postdoctoral Fellow in the Molecular Design Institute at NYU from 2012-2014 before joining Stevens Institute of Technology as an assistant professor. Her research group studies the crystal engineering of solution-processable semiconductors for emerging optoelectronic applications, including flexible displays and photovoltaics. Their strategies involve the use of solution rheology to monitor and control semiconducting polymer network formation, scaffold-directed crystallization of small molecules into vertical crystal arrays and nanoconfined crystallization to shift the thermodynamics and stability of metal-halide perovskites for high performance solar cells. Lee is a recipient of the Stevens Early Career Award for Research Excellence and a 2019 NSF CAREER awardee.
- Speaker: Christina Vizcarra, Assistant Professor of Chemistry, Barnard College
- Seminar Title: "Cytoskeletal regulation by formin proteins"
- Date & Time: Friday, October 20, 11:45 am - 12:45 pm
- Location: Druckenmiller Hall, Room 016
- Abstract: "The cytoskeleton is a dynamic network of protein filaments that is fundamental to many cellular processes. Formins are multifunctional regulators of both the actin and microtubule cytoskeletons. While small-molecule targeting of formins has been a standard method of studying their function, it is not well understood how small-molecule inhibitors affect these multifunctional proteins. Furthermore, the diversity of formins encoded by the human genome presents both challenges and opportunities for drug targeting. One of the first human genes that was linked to inherited deafness encodes the formin DIAPH1. In addition to investigating inhibitor/formin interactions, work in the Vizcarra lab also seeks to understand the link between formins and hearing by characterizing the growing number of deafness-associated DIAPH1 variants."
- Speaker: Monica Marie Arroyo, Professor of Chemistry, Pontifical Catholic University of Puerto Rico
- Seminar Title: "The power of networking: Exploring associations between cancer genes and drug candidates with GEDA."
- Date & Time: Friday, February 9, 2024, 3:30 - 4:30 pm
- Location: Druckenmiller Hall, Room 026
- Abstract: The World Health Organization (WHO) has identified cancer as the world's second-largest cause of death. In 2020, there were about 10 million deaths. Despite the significant progress over recent years in cancer treatment and new therapies, drug resistance remains one of the main biomedical challenges, as many patients do not react well to the pharmacological treatments or develop tumor progression after some initial drug reactivity due to resistance. Thus, developing new strategies to find new drug candidates for therapy is key to providing a fighting chance for cancer patients. We used a pharmacogenomic approach to perform an extensive screening by using the Cancer Gene Census targets and drug activity-expression data derived from CellMiner; we have analyzed over 700 cancer genes and 24,000 chemical compounds to discover new plausible interactions and resistance between drugs and oncogenes. Bioinformatic analyses were performed using R to calculate the significant Pearson and Spearman correlations between the expression profiles of the genes in a large set of cancer cell lines and the expression profiles of
the same cells when treated with different drugs. We focused our study on the activity of FDA-approved cancer drugs, and we also explored other molecules when they reported very significant
correlations. Based on the activity-expression patterns between FDA-approved drugs and their
known drug targets (i.e., their gene targets), we propose repurposing some of these drugs in
treating other types of cancers. Our analysis presents several molecules as prospective drugs for
expanding chemotherapeutic therapy. Moreover, we identified more than 1500 gene-drug
resistant pairs. Finally, we developed the open web tool GEDA with all the data integrated and
bipartite networks of interesting cancer-drug target modules. - Bio: I’m a full professor of chemistry at a primarily undergraduate (PUI), Hispanic-serving (HSI)
institution, teaching predominantly undergraduate organic chemistry. I work with a generally
disadvantaged population and seek to show them the beauty of chemistry and its possibilities
using an interdisciplinary approach based on the student’s career interests and the latest research. I also have vast administrative experience, working toward the accreditation of over 20 programs in the College of Business Administration and presiding over multiple institutional committees over the three PCUPR campuses. One of the most important assignments is to preside on the Academic Research Seed-Funding Committee. I work directly with faculty members across all fields to develop their grants and obtain internal and external research funding. I also preside
over the Academic Integrity Committee, which seeks to uphold the highest academic ethics
standards. I am active in the ACS nationally, collaborating mainly with the Division of Organic
Chemistry (DOC) and the Local Sections Activities Committee (LSAC). I have also served as Co-coordinator in the US National Chemistry Olympiads, providing support at the national level to
other coordinators, facilitating webinars, and assisting students from other local sections at the
request of the National USNCO staff. I love to cook, bake, and read in my spare time.
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- Speaker: Lee Penn, Professor and Director of Undergraduate Studies in Chemistry Department, University of Minnesota -Twin Cities
- Seminar Title: Iron Oxide Nanoparticles in Reactive Environments
- Date & Time: Friday, February 23, 2024, 3:30 - 4:30 pm
- Location: Druckenmiller Hall, Room 026
- Abstract: Iron is the fourth most abundant element in the Earth's crust, and iron bearing minerals are reactive in both natural and engineered aqueous systems. Mineralogy and crystal size and shape evolve substantially as a function of changing conditions and redox conditions. We quantitatively compare reactivity of natural and synthetic iron oxides in redox reactions with model pollutant molecules like nitroaromatics and quinones. We extensively characterize solid-state materials before, during, and after reaction as well as track the loss or production of dissolved species. Variables like the presence of organic matter (e.g., Suwanne River Natural Organic Matter) can dramatically change how minerals grow, dissolve, and transform.
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The seminar will highlight several examples of our ongoing work studying the reactivity of iron oxide nanoparticles in aqueous systems.
- Bio: Lee has been working with nanoparticles since the early 90s, and the Penn group’s research foci include understanding the fundamental formation and growth mechanisms of nanoparticles, how nanoparticles are involved in chemical transformations in the environment, and elucidating the link between magnetism and the physical and chemical properties of nanoparticles. Lee is a professor and also the Director of Undergraduate Studies for the Chemistry Department at the University of Minnesota - Twin Cities. They have served as a chemistry advisor, faculty advisor to several student groups, direct mentor to undergraduates through research projects and mentoring programs and developed innovative teaching techniques. Lee Penn has taught honors general chemistry; general chemistry; freshman seminars focusing on garbage, bikes, and nanotechnology; Nanoparticle Science and Engineering (co-taught with faculty from several departments); Green Chemistry; and Materials Characterization. Lee oversees a research group of eleven graduate students and several undergraduates - all working on various topics involving nano and/or sustainability and/or the environment.
- Pronouns: they/them
- Speaker: Aurelia Honerkamp-Smith, Assistant Professor
Department of Physics, Lehigh University - Seminar Title: Tiny forces from flow organize and measure membrane proteins
- Date & Time: Friday, March 29, 2024, 3:30 - 4:30 pm
- Location: Druckenmiller Hall, Room 016
- Abstract: The surface of a cell is crowded with membrane proteins, which mediate important physiological events like immune regulation, fertilization, and cell migration. The size, shape, density, and mobility of extracellular surface proteins mediate cell surface accessibility to external molecules, viral particles, and other cell membranes. However, predicting these qualities is not always straightforward, even when protein structures are known. We developed an experimental method for measuring flow-driven lateral transport of neutravidin bound to biotinylated lipids in supported lipid bilayers. We use this method to make quantitative measurements of hydrodynamic and drag forces applied to lipid-anchored proteins. We can measure membrane protein size and shape while proteins are in their natural, folded configuration. We show that membrane proteins can be spatially organized by small forces similar to those resulting from circulatory flow in blood vessels. Similar protein transport across living cells by hydrodynamic force may contribute to biological flow sensing. By using microfluidic flow to organize proteins, it’s possible to measure forces with sub-femtonewton precision (10-100 times smaller than the forces applied by thermal energy, individual molecular motors and in single molecule force spectroscopy experiments).
- Bio: Aurelia earned her Ph.D. from the University of Washington in Seattle, where she investigated static and critical dynamics in lipid membranes with Sarah Keller in the Department of Chemistry. Her discoveries were recognized by the national 2010 Anna Louise Hoffman Award for Outstanding Achievement in Graduate Research. As an Oppenheimer Fellow at the University of Cambridge, she imaged the flow of fluid, lipid membranes, and cell sheets by conventional fluorescence microscopy techniques and by building a light sheet microscope in the laboratory of Ray Goldstein in the Department of Applied Mathematics and Theoretical Physics. She joined the faculty of Lehigh University in 2016, where she is a tenure-track assistant professor.
- Speaker: Bob Rawle Assistant Professor of Chemistry at Williams College
- Seminar Title: The Molecular Biophysics of Viral Infection: A Single Virus Approach
- Date & Time: Friday, April 5, 2024, 3:30 - 4:30 pm
- Location: Druckenmiller Hall, Room 016
- Abstract: Have you ever wondered how viruses operate? How do they know which cells to infect? How do they “take over” a cell to cause it to make more viral particles? And why does this lead to disease and sometimes death? This presentation aims to demystify the inner workings of viruses, on a biophysical and biochemical level. Sharing work from my research lab, I will focus on the initial stages of infection using the Sendai virus which serves as an important model of viral infection. Although lesser-known, Sendai virus belongs to the same family as familiar respiratory viruses like mumps, measles, and parainfluenza viruses. The first steps of infection involve binding to host cells and merging with their membranes, a process known as membrane fusion. These steps are carried out by membrane proteins on the viral surface and are important targets for antiviral drug and vaccine development. While the key players in these processes have been identified, biophysical understanding of the mechanism has been challenging because these steps involve many molecules and a range of timescales. This presentation will highlight our investigations into receptor binding and membrane fusion of Sendai virus using a single-virus approach that involves microfluidic-based fluorescence measurements of individual viruses. I will discuss the biophysical insights that these investigations have yielded into the molecular mechanisms of binding and fusion for Sendai virus.
- Bio: Bob Rawle is an Assistant Professor of Chemistry at Williams College since 2018. He is a biophysical chemist by training and is interested in the biophysics of viral infection and lipid membranes. He received his BA in chemistry at Pomona College in 2008, where he worked in the laboratories of Profs. Cynthia Selassie and Malkiat Johal to develop bio-analytical methods to study DNA damage. He earned his PhD in chemistry (emphasis: biophysical chemistry) at Stanford University in 2014, working with Prof. Steve Boxer to study the membrane biophysics of vesicle fusion. He then did postdoctoral work at the University of Virginia Medical School with Prof. Peter Kasson studying the biophysics of influenza virus and Zika virus membrane fusion. Afterward, he had a short (but awesome) stint as a stay-at-home dad.
Bob loves teaching both in and out of the classroom. At Williams, Bob teaches classes in introductory chemistry, biochemistry, and biophysical chemistry. Outside of work, Bob regularly transforms into a terrifying ice dragon named Ice Fang and chases his three kids around the house. He enjoys swimming, cooking, and being outdoors.
Dana Mayo Memorial 海角直播 Chemistry Seminar
- Speaker: Amanda Peiffer, PhD (she/her) Postdoctoral Associate, Kiessling Lab, Department of Chemistry at Massachusetts Institute of Technology
- Seminar Title: An Antibiotic Impasse: Leveraging Glycobiology as a New Therapeutic Strategy for Resistant Infections
- Date & Time: Friday, April 12, 2024, 3:30 - 4:30 pm
- Location: Druckenmiller Hall, Room 016
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Abstract: Microbial infections are one of the top global threats — one out of every eight people globally dies from an infection. And as antibiotic resistance continues to rise, traditional anti-microbial strategies are reaching an impasse. My research as a chemical biologist is focused on trying something different. Instead of developing compounds to directly kill bacteria (which in turn could lead to resistance mechanisms), what if we instead recruited immune cells to an infection to clear it out naturally? Through this framework, I have synthesized glycopolymers to recruit phagocytotic cells to the site of Pseudomonas aeruginosa infections. With promising preliminary data, I believe this approach can be tailored to go after a dearth of antibiotic-resistant microbes.
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Bio: I’m passionate about liberal arts colleges because of my own experience at Denison University in Ohio, where I double majored in math and chemistry (2016). Liberal arts colleges encourage the kind of creative problem-solving and cross-disciplinary collaborations that are vital in today’s age of science. After college, I transitioned to a PhD in the Program in Chemical Biology at the University of Michigan under the co-advisement of Prof. Anna Mapp and Prof. Charles Brook III. There, I studied protein dynamics involved in transcriptional regulation using molecular dynamics simulations and in vitro assays, leveraging my math and biochemical skills. In 2021, I joined Prof. Laura Kiessling’s research group at the Massachusetts Institute of Technology as a post-doctoral associate. Since joining, I’ve been studying glycobiology, immunology, and microbiology.