Past Seminars and Panels


2019

March 19, 2019

Rio Febrian, Ph.D. Candidate, Bracher Lab, St. Louis University

Deliquescent Wet–Dry Cycling: A Tale from The Prebiotic and The Professional World
Elucidating the means by which the first functional biopolymers arose on Earth is a major focus of origin-of-life research. In my research, I explore the wet–dry cycling model— a widely regarded means of driving condensation reactions under prebiotic conditions to generate mixtures of prospective biopolymers. A criticism of this model is its reliance on unpredictable rehydration events, like rain storms. In this seminar, I will be talking about the ability of deliquescent minerals—which form aqueous solutions by absorbing water vapor— to mediate the oligomerization of glycine during spontaneous, iterative wet–dry cycles. The deliquescent mixtures can 1) foster yields of oligomerization over ten-fold higher than non-deliquescent controls, and 2) tightly regulate their moisture content. In parallel to my research, I will also talk about how we, as scientists, can apply the systematic, critical thinking approach of the scientific method to business and other everyday complex problems.

  • Kennesaw State University
     Clendenin Building, room 1009 (CL 1009) 12:30-1:30
February 11, 2019

Aaron McKee, Ph.D. Candidate, Orlando Lab, Georgia Insitute of Technology 
Primordial proto-proteins at a mineral interface: Interactions of silica and an expanded prebiotic peptide inventory

  • Northern Kentucky University
February 8, 2019

Aaron McKee, Ph.D. Candidate, Orlando Lab, Georgia Insitute of Technology 
Primordial proto-proteins at a mineral interface: Interactions of silica and an expanded prebiotic peptide inventory

  • Western Kentucky University
    1:00-2:00, SH 4114

2018

October 16, 2018

Alma Castaneda, Postdoctoral Researcher, Orlando Lab: Chemical Origins of Life in Aerosols
Tyler Roche, Ph.D. Student, Hud Lab: There and Back Again: A Grad Student’s Tale
George Tan, Ph.D. Candidate, Stockton Lab: Characterization of the Dyngjusandur Alluvial Plain in Iceland with an Analog of a Mars Instrumentation Suite Join us for presentations by three GT chemistry researchers as well as an informal discussion of research life. Topics covered include aerosol, analytical, and biochemistry.

  • CCE Graduate Research Envoy Panel
  • Kennesaw State University, Clendenin Building Room 2010
October 5, 2018

Kristin McKenna, Graduate Student, Georgia Institute of Technology; Ariel Parker, Graduate Student, Georgia Institute of Technology; Micha Schiable, Postdoctoral Fellow, Georgia Institute of Technology

  • CCE Graduate Research Envoy Panel
  • Clayton State University, Lakeview Science and Discovery Center
September 4, 2018

Christine He, Postdoctoral Fellow, UC Berkeley

  • Investigating the Microbial Dark Matter with Metagenomics and Biochemistry
  • Kennesaw State University, Clendenin Building, room 1009 (CL 1009) 12:30-1:30

  • Microorganisms are the most diverse and abundant cellular life forms on Earth, and the source of many pharmaceuticals. However, our understanding of the microbial world is largely limited to the tiny set of microbes that can be grown alone, in pure culture. We know very little about the vast majority of microbes which cannot yet be cultured: the "microbial dark matter." In the past decade or so, a new set of methods called metagenomics has enabled us to probe the genetics of uncultured microbes. Metagenomics involves the bioinformatic assembly of genomes from total DNA sampled directly from the environment.

    In particular, metagenomics studies led by the Banfield lab at UC Berkeley have led to the classification of a vast, previously undefined monophyletic group in Domain Bacteria named the candidate phyla radiation (CPR), composed almost entirely of uncultivated organisms. CPR bacteria are incredibly diverse, comprising >15% of all diversity in Domain Bacteria, and ubiquitous, found in nearly every known environment. All members share unusual features that are divergent from other bacteria, including very small cell sizes, compact genomes, and a lack of many integral biosynthetic abilities. 

    Currently, almost no biochemical or molecular level characterization of CPR bacteria has been done. However, the few studies that have been performed have already revealed novel, highly compact CRISPR-Cas immunity systems and divergent RubisCO enzymes. CPR bacteria represent a huge, unexplored potential source of novel biochemical tools and pharameceuticals. I will talk about the development of methods to detect and characterize CPR bacteria on a molecular level, as well as efforts to cultivate CPR bacteria.

March 6, 2018

Thomas Campbell, Graduate Student, St. Louis University

  • Potassium and the Prebiotic Formation of Poly-Peptides
  • Kennesaw State University, Clendenin Building, room 1009 (CL 1009) 12:30-1:30
  • The intracellular enrichment of K+ (relative to Na+) by modern life is nearly as universal as the central dogma of biochemistry, suggesting that these ions could have played an important role in the development of early life. We have studied the impact of K+ and Na+ on simple organic reactions relevant to the origin of life — specifically, the hydrolysis and condensation of peptides. We found that K+ and Na+ affect the rate of peptide hydrolysis in an unexpected, substrate-dependent pattern. We also found that these ions differentially impact the yield for the condensation of amino acids via wet–dry cycling. These results raise the possibility that the ubiquitous selection for intracellular potassium over sodium observed in modern life developed early in evolution to optimize the kinetics of reactions of peptides.
February 20, 2018

David Fialho, Graduate Student, Georgia Institute of Technology

  • Before Life: The Origin of Proto-RNA
  • Kennesaw State University, Clendenin Building, room 1009 (CL 1009)
  • The popular RNA world hypothesis of the origin of life states that the first living systems on Earth relied solely on RNA to carry out their hereditary and metabolic functions. However, simulating the spontaneous prebiotic emergence of RNA is profoundly challenging, as the many precise structural features of RNA are difficult to produce in the absence of highly evolved enzymes. In light of this, we hypothesize that RNA itself is the product of an evolutionary process, and was preceded by informational molecules which were more readily accessed by prebiotic chemistry. In particular, we have investigated alternative nucleobases, which react much more readily with sugars than the canonical nucleobases to form nucleosides, and alternative sugars, which would have been produced alongside ribose and can also react with bases to form glycosides. The productive reactions demonstrated from these prebiotically plausible, noncanonical compounds demonstrates that the assumption of the direct prebiotic emergence of RNA is ill-founded, and that the formation of informational molecules on the early Earth may have been a robust process if potentially ancestral alternatives to RNA are considered.

2017

November 14, 2017
  • David Fialho, Graduate Student, Moran Frenkel-Pinter, Postdoctoral Researcher, and Robert Kubiak, Graduate Student
    • "CCE/CCHF Graduate Envoy panel"
  • Clayton State University, 210 Lakeview Science Center, 3:30 PM
November 7, 2017
  • Ariana Lozoya, Graduate Student, Chiamaka Obianyor, Graduate Student, and Helen Siaw, Graduate Student
    • "CCE/CCHf Graduate Envoy Panel"
  • Spelman College, Science Learning Center, room 337
October 17, 2017
  • David Fialho, Graduate Student, Kristin McKenna, Graduate Student, and Martin Solano, Graduate Student
    • "Center for Chemical Evolution Graduate Research Panel"
  • Kennesaw State University, Clendenin Building, room 1009 (CL 1009)
April 18, 2017
  • Dr. Jesse Gavette, Postdoctoral Researcher, Furman University
    • "Exploring the Role of Heterogeneous Backbones in the Transition from an RNA World to an RNA/DNA World"
  • Kennesaw State University, Clendenin Building, room 1009 (CL 1009)
April 14, 2017
  • Adriana Lozoya, graduate student, Aaron McKee, graduate student, and Dr. Anyin Li, postdoctoral researcher
    • Center for Chemical Evolution Graduate Research Panel
  • Clayton State University, 210 Lakeview Science Center, 12:30 PM
February 9, 2017
  • Dr. Molly Hopper, Postdoctoral Research Scientist, School of Chemistry and Biochemistry, Georgia Institute of Technology
    • "Machine Learning-Enabled Collision Cross Section Predictor for application to Pre-biotic Chemistry"
  • Kennesaw State University, Clendenin Building, room 1010 (CL 1010)

Abstract: The importance of lipids in maintaining cell membrane integrity, storing energy, and cell signaling, is well documented. Lipids may have also played a role as building blocks of membranous boundary structures critical for early cellular life. Identification of unknown lipids is typically achieved using high resolution MS and MS/MS, together with database matching. This approach can fail if no MS/MS information is available, or if the database is incomplete. Recently, ion mobility measurements have allowed for the compilation of lipid collisional cross section (CCS) databases, aiding in identification. This approach is still dependent on database completeness. Discussed here is a method for lipid identification based on using molecular descriptors to predict CCS values for proposed lipid structures, even if unknown. Additionally, previous work within the Center for Chemical Evolution has revealed a potential pathway for the formation of peptides on the early earth. The CCSP tool developed for lipids has been applied to databases of protopolypeptides, in attempts to identify sequences which may have functionality.

Spring 2016

April 15, 2016
  • Sheng-Sheng Yu, Graduate Student, School of Chemical and Biomolecular Engineering, Georgia Institute of Technology 
    • ​"An Engineering Approach to Finding the Best Possible Path to Proteins in the Prebiotic World"
  • ​Clayton State University, 210 Lakeview Science Center, 12:30 PM

​Abstract: Sixty years ago, Miller and Urey demonstrated the formation of small organic molecules from inorganic species by an electric discharge experiment. Ever since their success, scientists have wondered whether those small organics on the prebiotic Earth can lead to the molecules of life today (RNA, sugars and proteins). One of the important products from Miller’s experiment is amino acids, the small units from which the large polymers known as proteins are made. However, the reaction from amino acids to proteins is difficult without enzymes. In the NSF/NASA Center for Chemical Evolution at Georgia Tech, we are searching for possible pathways used by those small molecules to evolve into large macromolecules. In this talk. I will introduce the chemistry that can lead to the formation of peptide bonds. Our proposed pathway involves the copolymerization between amino acids and hydroxy acids in wet-dry cycles. We further combine both experimental and model-based approaches to achieve an in-depth analysis on the mechanism and the kinetics of this complex copolymerization.  

February 19, 2016
  • Dr. Suneesh Karunakaran, postdoctoral researcher, School of Chemistry and Biochemistry, Georgia Institute of Technology 
    • "Understanding the Origin of Homochirality in Nature: Symmetry Breaking and Chiral Domains. 
  • ​Kennesaw State University, Clenndennin Building 1009, 1:00

Abstract: 

Chirality is a basic characteristic of nature, where we can see the selection of only "left-handed" amino acids and "right-handed" sugars for our bodies, even though synthesizing these compounds gives a mixtures of both the right- and left-handed ones.1 By considering the possibility that the origin of life could have dependent on the molecular and supramoelccular chirality, the chiral behavior of various supramolecular systems containing various chiral monomers were extensively studied.2 On the other hand the origin of macroscopic chirality from supramolecular systems containing achiral monomers were rarely studied.3

In this context, we have investigated the chiral behavior of supramolecular polymers/hydrogels formed from monomers that mimic the base pairs of nucleic acids, (2,4,6-triaminopyrimidine (TAP) and cyanuric acid modified with hexanoic acid tail (CyCo6) (Fig. 1A).4 The supramolecular assembly formed from these achiral monomers showed macroscopic chirality at the absorption region of TAP through symmetry breaking. Interestingly, we observed inversion of chirality of TAP-CyCo6 assembly with changes in temperature of the sample (Fig. 1B). Detailed investigation of these assemblies using circular dichroism spectroscopy and polarized optical microscopy revealed the formation of chiral domains of opposite handedness with in the same sample system (Fig. 1C). Moreover, we found that homochirality could be achieved by doping with 0.1% chiral derivatives of CyCo6.

In light of our results, we propose the mechanism of chiral domain separation and selection for the origin of homochirality in nature. To better demonstrate this mechanism, we have synthesized D(-) and L(+) enantiomers of the nucleotide derived from the TAP. Detailed experiments to demonstrate the formation of chiral domains in the assembly formed from racemic mixture of these enantiomers using circular dichroism spectroscopy and optical polarizing microscopy are in progress in our laboratory. 

January 29, 2016
  • Dr. Jay Forsythe, Postdoctoral Researcher, School of Chemistry and Biochemistry, Georgia Institute of Technology
    • "Investigating the Origins of Proteins in Darwin's Warm Little Pond"
  • ​Clayton State University, 210 Lakeview Science Center, 12:00 PM 

Abstract: In 1871, several years after publishing his world-famous book The Origin of Species, Charles Darwin wrote a letter to a friend pondering how the first cells came into existence. Darwin knew that many chemicals would have had to come together to form life (now known to be DNA, RNA, proteins, fats, etc.), and that these molecules would have experienced evolution based on their environments - just like biological species. Under the NSF/NASA Center for Chemical Evolution at Georgia Tech, we are currently studying ways the molecules of life could have formed and evolved billions of years ago, even before the first cell came into being. Here, I will discuss chemistry which could explain how proteins formed which is based off evaporating pools of water. This chemistry enables the formation of amide, or peptide, bonds between amino acids without the assistance of enzymes.

Spring 2015 

April 23, 2015


* Nikita La Cruz, Graduate Student, School of Geosciences, University of South Florida
o "Synthesis and Corrosion of Schrebersite and Possible Origins of Life Applications"
* Kennesaw State University, 1009 Clendennin Building, 2:00
Abstract: This presentation focuses on the synthesis of an analog of the meteoritic mineral schreibersite, believed to be a prebiotic source of reactive phosphorus which was significant to the origin of life. Synthesized by mixing stoichiometric proportions of iron, nickel and phosphorus and heating in a tube furnace with an argon atmosphere. Mineral characterization indicates that both schreibersite,  and nickel phosphide were synthesized. 
Corrosion experiments of the synthesized mineral in prebiotically relevant solutions will be presented. After corrosion, the solutions were used to determine phosphorus speciation as well as concentrations of phosphorus present in solution. Analysis results indicate that the extent of the  mineral’s corrosion, measured by the concentration of phosphorus released, depends on the ionic  strength of the solution, as well as the presence of the chelating agent. The successful phosphorylation of prebiotic molecules, such as choline, using synthesized schreibersite is also reported.  
 

March 26, 2015


* Aaron McKee, Graduate Student, School of Chemistry and Biochemistry, Georgia Institute of Technology
o "Mineral Surfaces: A Stage for Chemical Evolution"
* Kennesaw State University, 1009 Clendennin Building, 2:00
Abstract: 
The origin of life is typically thought to have begun with the abiotic synthesis of simple organic compounds and to have proceeded to the self-assembly of these precursors into more complex self-replicating systems. The ubiquitous presence of minerals on prebiotic Earth and the abundance of heterogeneous liquid-mineral interfaces makes it essentially impossible to ignore the potential relevance of surface mediated processes to chemical evolution. Whereas modern biology principally employs protein enzymes, prebiotic minerals might have had roles in catalysis, molecular concentration, product protection, and may have even participated in some reactions.
Here, mineral evolution and various mineral-organic interfacial processes will be discussed in the context of the origin of life, including the specific systems of oligopeptide formation on mineral substrates and a mineral source of reactive phosphorous.


February 19, 2015


* Chris Butch, Postdoctoral Researcher, School of Chemical and Biomolecular Engineering, Georgia Institute of Technology
o "Using NMR and Density Functional Theory to Search for the Chemistry of Life's Origin"
* Kennesaw State University, 1009 Clendennin Building, 2:00
Abstract: 
Glyoxylic acid (CHO-COOH) is an under explored building block for the chemistry of life's origin. Dr. Butch’s work has focused on detailed mechanistic analysis of the chemistry of glyoxylate, which can lead to molecules intrinsic to modern metabolism. He will present two aqueous reactions of glyoxylate and dihydroxyfumarate, the dimer of glyoxylate. The ??irst reaction, at pH 8, leads to the production of dihydroxyacetone, a building block of modern sugars. The second, at pH 13, leads ??irst to tartrate and subsequently to the intermediates of the citric acid cycle. Despite identical stoichiometry, these two reactions yield vastly different suites of products. Butch will present how his group used quantitative 13C-NMR kinetics combined with density functional theory to showthat the extent of deprotonation of a crucial intermediate, common to both reactions, dictates the course of the reaction pathway, diverting it towards differing products, depending on the pH of the reaction medium.


January 22, 2015

 
* Christine He, Graduate Student, School of Chemical and Biomolecular Engineering, Georgia Institute of Technology
o "The Emergence of Nucleic Acid Replication During the Origin of Life"
* Kennesaw State University, 1009 Clendennin Building, 2:00
Abstract: 
DNA replication is an essential process in life today, passing on the genetic blueprint of a species across generations. However, its prebiotic origins are poorly understood. In living organisms, DNA replication is a complex process that requires highly specialized enzymes. But on the early Earth, at a time before modern cells evolved, researchers believe that self-replicating nucleic acids appeared before enzymes did.
How did the first informational molecule replicate without the aid of enzymes?
Christine He will present a potential pathway to nucleic acid replication on the early Earth, driven not by enzymes but by the prebiotic environment. A pool of water, small organic solutes, and nucleic acids on the early Earth would have undergone cyclical changes in temperature and water level during day/night cycles, which could have driven the different steps of replication.