Seminars Archive

Fall 2017

Designing nanoparticles for sustainability

Designing nanoparticles for sustainability

Professor Christy Haynes | University of Minnesota

Professor Rebecca Pompano

Engineered nanoparticles are increasingly being incorporated into devices and products across a variety of commercial sectors – this means that engineered nanoscale materials will either intentionally or unintentionally be released into the ecosystem. The long-term goal of the presented work is to understand the molecular design rules that control nanoparticle toxicity using aspects of materials science (nanoparticle design, fabrication, and modification), analytical chemistry (developing new assays to monitor nanotoxicity), and ecology (monitoring how nanoparticles enter and accumulate in the food web through bacteria and how these nanoparticles influence bacterial function). Taken together, these data suggest that careful consideration of engineered nanoparticle surface chemistry will likely allow design of safe and sustainable nanoscale materials.

Professor Christy Haynes | University of Minnesota
Hosted by Professor Rebecca Pompano
Friday, September 22, 2017

New Recipes for Biocatalysis: Expanding the Cytochrome P450 Chemical Landscape

New Recipes for Biocatalysis: Expanding the Cytochrome P450 Chemical Landscape

Professor Eric Brustad | University of North Carolina, Chapel Hill |

Professor Ken Hsu
Professor Eric Brustad | University of North Carolina, Chapel Hill |
Hosted by Professor Ken Hsu
Friday, September 15, 2017

New recipes for biocatalysis: Expanding the cytochrome P450 chemical landscape

New recipes for biocatalysis: Expanding the cytochrome P450 chemical landscape

Professor Eric Brustad | University of North Carolina, Chapel Hill

Professor Ken Hsu

The design and engineering of protein catalysts that carry out rare or non-natural chemistry remains a challenging contemporary goal. However, enzymes are inherently limited by their chemical composition, i.e. the reagent pool that exists in nature and the amino acids and cofactors that form their physical and catalytic core. Because of this limitation, the majority of chemical transformations developed by synthetic chemists remain, at least to our knowledge, biologically inaccessible. Biological cofactors and prosthetic groups, including heme, provide a convenient means for natural proteins to increase their range of chemical transformations. Synthetic catalysts, similar to heme, demonstrate a wealth of chemical transformations, including metallocarbene insertion reactions, through mechanisms similar to native P450 catalysis; however, these reactions do not exist in biology due to the lack of the necessary ingredients in the cell or surrounding environment. By supplementing cytochrome P450s with non-natural reagents we have been able to demonstrate that a variety of natural enzyme scaffolds are capable of carrying out reactions, including the carbene-mediated cyclopropanation of olefins, not previously observed in the natural world. Moreover, as adaptable, genetically encoded systems, the activity and product regio- and stereochemical profiles of these catalysts can be tuned through mutation. We have shown that this non-natural chemistry can be applied for fine chemical synthesis, or even adapted to modify native P450 substrates. We have gone on to show that cytochrome P450s can be evolved for the incorporation of alternative metalloporphyrin scaffolds. By combining non-natural cofactor engineering with an increase in reagent diversity, we are generating orthogonal protein systems that deliver function not available to heme containing proteins.

 

Eric Brustad is a proud native of Indianapolis, Indiana. He graduated from Purdue University (W. Lafayette, IN) in 2002 receiving B.S. degrees in Chemistry and Biology as well as a B.A. in French. As an undergraduate, he began his research career in bioorganic chemistry under the mentorship of Jean Chmielewski. In the fall of 2002, he joined The Scripps Research Institute to carry out graduate research under the direction of Peter G. Schultz. His thesis work examined applications of unnatural amino acid mutagenesis to expand protein function. Dr. Brustad moved to the California Institute of Technology in December of 2008 as a Ruth Kirschstein postdoctoral fellow where he joined the group of Frances H. Arnold. While at Caltech, Dr. Brustad applied directed protein evolution to engineer proteins for non-natural catalysis or biosensing applications. In 2012, Eric joined the Department of Chemistry and the Carolina Center for Genome Sciences at the University of North Carolina at Chapel Hill. His research program focuses on combining chemical, biological and evolutionary approaches to expand the capabilities of living cells.  His honors include the Barry M. Goldwater Scholarship (2002), a Ruth L. Kirschstein National Research Service Award (2009), a DARPA Young Faculty Award (2013), and an NSF Career Award (2015).

Professor Eric Brustad | University of North Carolina, Chapel Hill
Hosted by Professor Ken Hsu
Friday, September 15, 2017

Searching for selective catalytic reactions in complex molecular environments

Searching for selective catalytic reactions in complex molecular environments

Professor Scott Miller | Yale University

Professor Mike Hilinski

This lecture will describe recent developments in our efforts to develop low-molecular weight catalysts for asymmetric reactions.  Over time, our view of asymmetry has ebbed and flowed, with foci on enantioselectivity, site-selectivity and chemoselectivity.  In most of our current work, we are studying issues of enantioselectivity as a prelude to extrapolation of catalysis concepts to more complex stereochemical settings where multiple issues are presented in a singular substrate.  Moreover, we continuously examine an interplay between screening of catalyst libraries and more hypothesis-driven experiments that emerge from screening results.  Some of the mechanistic paradigms, and their associated ambiguities, will figure strongly in the lecture.

 

Scott J. Miller was born on December 11, 1966 in Buffalo, NY. He received his B.A. (1989), M.A. (1989) and Ph.D. (1994) from Harvard University, where he worked with David Evans as a National Science Foundation Predoctoral Fellow.  Subsequently, he traveled to the California Institute of Technology where he was a National Science Foundation Postdoctoral Fellow with Robert Grubbs until 1996. For the following decade, he was a member of the faculty at Boston College, until joining the faculty at Yale University in 2006.  In 2008, he was appointed as the Irénée duPont Professor of Chemistry.

Professor Miller’s research program focuses on catalysis. His group employs strategies that include catalyst design, the development of techniques for catalyst screening, and the application of new catalysts to the preparation of biologically active agents.  Three current interests are (a) the selective functionalization of complex molecules, (b) the exploration of analogies between synthetic catalysts and enzymes and (c) the discovery of effective antibiotics despite increasing resistance.

Scott Miller’s awards and honors include: National Science Foundation CAREER Award (1999), Alfred P. Sloan Research Fellowship (2000), Camille Dreyfus Teacher-Scholar Award (2000), Arthur C. Cope Scholar Award of the American Chemical Society (2004), Yoshimasa Hirata Memorial Gold Medal of Nagoya University (2009), National Institutes of Health MERIT Award (2011), Fellow of the American Association for the Advancement of Science (2012), American Chemical Society Award for Creative Work in Synthetic Organic Chemistry (2016), Member, American Academy of Arts and Sciences (2016), Max Tishler Prize, Harvard University (2017).

Professor Miller has served in number of capacities for public and private organizations.  For example, he recently completed a term on the National Institute of General Medical Sciences Advisory Council, convened by the Director of the National Institutes of Health.  He now serves as Editor-in-Chief of The Journal of Organic Chemistry.

Professor Scott Miller | Yale University
Hosted by Professor Mike Hilinski
Friday, September 8, 2017

Expanding the imaging toolbox

Expanding the imaging toolbox

Professor Jennifer Prescher | University of California, Irvine

Professor Linda Columbus

Imaging tools have revolutionized our understanding of living systems by enabling researchers to “peer” into tissues and cells and visualize biological features in real time.  While powerful, these probes have been largely confined to monitoring cellular behaviors on a microscopic level.  Visualizing cellular interactions and functions across larger spatial scales—including those involved in cell migration to distant tissues, immunosurveillance, and other biological processes—remains a daunting task.  My research group is developing general toolsets to image such macroscopic cellular networks and behaviors, and our efforts are focused in two areas: generating novel bioluminescent probes and developing new bioorthogonal chemistries for imaging in vivo.

Professor Jennifer Prescher | University of California, Irvine
Hosted by Professor Linda Columbus
Friday, September 1, 2017

Spring 2017

Structural and dynamic studies of supramolecular assemblies by solid-state NMR spectroscopy

Structural and dynamic studies of supramolecular assemblies by solid-state NMR spectroscopy

Chris Jaroniec | Professor, Ohio State University

Professor Dave Cafiso

I will present recent work from my lab on the development and applications of magic-angle spinning solid-state nuclear magnetic resonance (NMR) techniques toward the structural and dynamic analysis of supramolecular protein and protein-DNA assemblies. The main topics will include: (1) new paramagnetic solid-state NMR methodologies for the rapid determination of three-dimensional protein structures and (2) studies of mammalian Y145Stop prion protein variants aimed at providing an atomic level structural basis for the phenomena of amyloid strains and cross-seeding barriers associated with these proteins. If time permits, I will also discuss our studies of the flexible histone N-terminal tail domains in large nucleosome arrays under experimental conditions corresponding to extended, folded and highly condensed chromatin.

Biosketch

Christopher Jaroniec received his B.S. degree in Chemistry from Kent State University in 1997 and his Ph.D. in Physical Chemistry from the Massachusetts Institute of Technology in 2003, where he was a National Science Foundation Graduate Research Fellow with Prof. Robert Griffin, and he was a Damon Runyon Cancer Research Foundation Postdoctoral Fellow with Dr. Ad Bax at the National Institutes of Health. He joined The Ohio State University as an Assistant Professor in 2006, was promoted to Associate Professor in 2011 and Professor in 2014, and named Evans Scholar in 2013. He currently also serves as the Vice Chair for Research and Administration in the Department of Chemistry and Biochemistry and the Director of the OSU CCIC Solid-State NMR Center, which houses multiple state-of-the-art high-field solid-state NMR instruments. Professor Jaroniec’s research in biomolecular solid-state NMR spectroscopy has been recognized by multiple awards including the NSF CAREER Award, the Eli Lilly Young Investigator Award in Analytical Chemistry, the Camille Dreyfus Teacher-Scholar Award, the Founders’ Medal from the International Council on Magnetic Resonance in Biological Systems, and the ACS Physical Division Early-Career Award in Experimental Physical Chemistry. He was also elected as Fellow of the American Association for the Advancement of Science and has held an Invited Visiting Professor position at Sorbonne Universités/Université Pierre et Marie Curie in Paris, France.

Chris Jaroniec | Professor, Ohio State University
Hosted by Professor Dave Cafiso
Friday, April 7, 2017

Colloidal metal nanocrystals: From academic studies to industrial applications

Colloidal metal nanocrystals: From academic studies to industrial applications

Younan Xia | Professor, Behrens Departamento de Quimica Inorganica Facultad de Quimica Universidad Nacional Autonoma de Mexico |

Professor Sen Zhang
Younan Xia | Professor, Behrens Departamento de Quimica Inorganica Facultad de Quimica Universidad Nacional Autonoma de Mexico |
Hosted by Professor Sen Zhang
Friday, March 17, 2017

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