Prof. JoAnne Stubbe - MIT
Seminar Title: "Radicals: Your Life is in Their Hands"
Thursday, September 15
RECEPTION TO FOLLOW IN CBEC LOBBY
Prof. Stubbe is a celebrated enzymologist whose lab has revealed the mechanisms of some of nature’s most complex and fundamentally important enzymes. A particular focus over her career has been on defining how enzymes harness the reactivity of free radicals to carry out complicated enzyme chemistry, perhaps most notably leading to groundbreaking insights into the essential ribonucleotide reductase enzyme family. Through her long-standing collaboration with the Nocera Lab, she continues to add to our structural and molecular understanding of these fascinating enzymes. Her outstanding career has been recognized by numerous National and International awards, including the National Medal of Science which she was awarded in 2009.
Radicals in biology are often described without distinction as reactive oxygen or nitrogen species (ROS, RNS) and are vilified in the popular press as agents of aging and cell death. Radicals, however, are ubiquitous in biology. They play a central role in cofactor biosynthesis used to expand the repertoire of enzyme-catalyzed reactions. Stable and transient amino acid radicals of tyrosine, cysteine, glycine, and tryptophan within enzymes have been identified that play important roles in central metabolism. Since the discovery of ribonucleotide reductases (RNRs) in the late 60s, these enzymes have held a pre-eminent position as they are essential in the biology of all organisms providing the monomeric building blocks required for DNA replication and repair and in controlling the fidelity of these processes. Studies of RNRs have led to the development of new tools and guiding principles for the study of radicals in biology. They have established that Nature can harness the reactivity of radicals to achieve very difficult chemical transformations with exquisite specificity. Studies on RNRs have led to the discovery of new therapeutics currently used in the treatment of cancers and recently established it as a new target for antibiotics. Today we will discuss how recent cryo-EM structures made possible by technology that allows site-specific incorporation of unnatural amino acids, together with three decades of studies using mechanism-based inhibitors, kinetic studies on the ms to ns time scales, and high field multi-frequency paramagnetic resonance methods to establish structures of radical intermediates, have all come together to provide us with amazing insight about the how these machines function.
History of The William Lloyd Evans Lectures
The Evans Lecture at Ohio State University was established in 1961 upon the dedication of Evans Laboratory, in recognition of the late William Lloyd Evans for his distinguished service to the Department of Chemistry. Each year, a faculty committee has been charged with selecting a chemist of outstanding international stature to receive the Evans Award and present the Evans Lecture.
William Lloyd Evans (b. 1871) received his M.S. degree in 1896 from Ohio State and joined the Chemistry Department faculty in 1905 after having received his Ph.D. degree that year under Professor Ulric Nef at the University of Chicago. As an Assistant Professor in charge of the course in General Chemistry, “Billy” Evans was soon recognized as an especially effective and inspiring teacher. He rose to the rank of Full Professor in 1911, and his service to the Department was interrupted only by a two-year period of military service during World War I at Edgewood Arsenal. In 1928, he was named Chairman, succeeding Professor William McPherson.
During his tenure as Chairman, a post that he held until 1941, he guided the Department toward increased emphasis on graduate research. He encouraged the development of a strong research-oriented faculty and the expansion of research through involvement of outside industry and government agencies in sponsored programs. Following his retirement in 1941, Professor Evans was elected President of the American Chemical Society, and he continued his work in chemistry during active retirement until his death in 1954 at the age of 83.
2019 - Jack Szostak
2018 - Judith P. Klinman
2016 - Daniel Nocera
2015 - Angela Gronenborn
2014 - Carol Robinson
2013 - Jacqueline K. Barton
2012 - Chris Dobson
2011 - Sumio Iijima
2010 - Carolyn Bertozzi
2009 - Professor W. E. Moerner
2008 - Doug Rees
List of Previous Lectures back to 1962.pdf
Note: This lecture was made possible by financial support from the Dr. Robert H. Lawrence Jr. Endowed Fund in Chemistry, the Dr. Kurt L. Loening Endowment Fund in Chemical Nomenclature and Chemical Information, the Chemistry Lecture Fund, as well as numerous other donors.