January Monthly Meeting

Spectroscopy Society of Pittsburgh Monthly Meeting

WHEN: Wednesday – January 18, 2016
WHERE: Duquesne University
RSVP BY: Friday, January 13, 2016 at 12:00 noon

Dinner reservations are no longer being accepted.

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Technology Forum Speaker’s Presentation & Social Hour: 5:30 PM – Power Center Ballroom Section C
Social Hour: 5:30 PM – Power Center Fides Shepperson Suite
Dinner: 6:45 PM – Power Center Ballroom Section C
Business Meeting: 8:00 PM – Power Center Ballroom Section C
Technical Program Speaker’s Presentation: 8:15 PM – Power Center Ballroom Section C

Jennifer Adibi MPH, ScD, Assistant Professor, Department of Epidemiology, Department of Obstetrics, Gynecology and Reproductive Sciences, University of Pittsburgh

“Zika Virus and Microcephaly: Old Biology and New Realities”
Based on the first wave of data from Brazil in early 2016, the U.S. C.D.C. declared strong certainty in the causal relationship between exposure to Zika virus in pregnancy and the risk of the child being born with microcephaly. The quantitative estimates of absolute and relative risk vary widely based on different assumptions made in the models. So far, there are only 2 published empirical studies that offer unstable estimates of risk. It is a rare event when an epidemiologist can watch a teratogenic investigation unfold in real time. In this presentation, I will provide updates in terms of what we know about Zika virus, its spread to other countries, and the risk of microcephaly. I will take a slightly deeper dive into the value and importance of understanding a critical mediator of this relationship – the placenta. …READ BIO

Karen N. Allen, Boston University, Department of Chemistry, Boston, MA

“How Structure and Dynamics Dictate Specificity and Regulation in a Superfamily of Phosphatasese”
The haloalkanoate dehalogenase superfamily (HADSF) of enzymes is a ubiquitous superfamily represented in the proteomes of organisms from all three domains of life, wherein its members participate in numerous diverse biological processes. Because of the occurrence of the family in all domains of life and the number of homologues within each organism the members provide numerous examples of orthologues to study determinants of specificity and paralogues to study function diversification. The HADSF has successfully evolved several forms of chemical transformation and has experienced expansion through substrate space. Notably, members show “substrate blurring”, with activity toward a number of substrates and significant substrate overlap between “paralogues”. Other family members have been honed to a specific substrate with high catalytic efficiency and proficiency. The construction of the family is functionally modular, with conserved chemistry provided by the Rossmann fold “core” domain and specificity provided by the accessorizing cap domain. We offer evidence, through X-ray crystallography and bioinformatic analysis at the sequence and structure level, for coevolution of the cap and core domains. Moreover, the observed correlated variation is a global phenomenon with contributions from all residues of the core fold. These findings are supported by experimental thermodynamic stability studies showing cooperative unfolding of the two enzyme domains. Small angle X-ray scattering studies, combined with molecular dynamics of a mutase member of the HADSF, β-phosphoglucomutase, in complex with ligands representing various substrate moieties show that occupation of the “non-transferring” phosphate-binding site is required for closure of the enzyme complex. This use of ligand-mediated conformational dynamics is also key to the “allosteric’ regulation of the related enzyme α-phosphomannomutase. Overall, our findings highlight the use of the cap domain structure and enzyme conformational dynamics in delineating specificity. …READ BIO