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Bada, JL, Ehrenfreund P, Grunthaner F, Blaney D, Coleman M, Farrington A, Yen A, Mathies R, Amudson R, Quinn R, Zent A, Ride S, Barron L, Botta O, Clark B, Glavin D, Hofmann B, Josset JL, Rettberg P, Robert F, Sephton M.  2008.  Urey: Mars Organic and Oxidant Detector. Space Science Reviews. 135:269-279.   10.1007/s11214-007-9213-3   AbstractWebsite

One of the fundamental challenges facing the scientific community as we enter this new century of Mars research is to understand, in a rigorous manner, the biotic potential both past and present of this outermost terrestrial-like planet in our solar system. Urey: Mars Organic and Oxidant Detector has been selected for the Pasteur payload of the European Space Agency's (ESA's) ExoMars rover mission and is considered a fundamental instrument to achieve the mission's scientific objectives. The instrument is named Urey in recognition of Harold Clayton Urey's seminal contributions to cosmochemistry, geochemistry, and the study of the origin of life. The overall goal of Urey is to search for organic compounds directly in the regolith of Mars and to assess their origin. Urey will perform a groundbreaking investigation of the Martian environment that will involve searching for organic compounds indicative of life and prebiotic chemistry at a sensitivity many orders of magnitude greater than Viking or other in situ organic detection systems. Urey will perform the first in situ search for key classes of organic molecules using state-of-the-art analytical methods that provide part-per-trillion sensitivity. It will ascertain whether any of these molecules are abiotic or biotic in origin and will evaluate the survival potential of organic compounds in the environment using state-of-the-art chemoresistor oxidant sensors.

Bada, J, Finkel R.  1983.  The upper pleistocene peopling of the New World: evidence derived from Radiocarbon, Amino acid racemization and Uranium serius dating. Quaternary coastline and marine archeology: towards the prehistory of land bridges and continental shelves. ( Masters PM, Flemming NC, Eds.).:463-479., London: Academic Press
Bump, JK, Fox-Dobbs K, Bada JL, Koch PL, Peterson RO, Vucetich JA.  2007.  Stable isotopes, ecological integration and environmental change: wolves record atmospheric carbon isotope trend better than tree rings. Proceedings of the Royal Society B-Biological Sciences. 274:2471-2480.   10.1098/rspb.2007.0700   AbstractWebsite

Large-scale patterns of isotope ratios are detectable in the tissues of organisms, but the variability in these patterns often obscures detection of environmental trends. We show that plants and animals at lower trophic levels are relatively poor indicators of the temporal trend in atmospheric carbon isotope ratios (delta C-13) when compared with animals at higher trophic levels. First, we tested how differences in atmospheric delta C-13 values were transferred across three trophic levels. Second, we compared contemporary delta C-13 trends (1961 - 2004) in atmospheric CO2 to delta C-13 patterns in a tree species ( jack pine, Pinus banksiana), large herbivore (moose, Alces alces) and large carnivore (grey wolf, Canis lupus) from North America. Third, we compared palaeontological (approx. 30 000 to 12 000 14 C years before present) atmospheric CO2 trends to delta C-13 patterns in a tree species (Pinus flexilis, Juniperus sp.), a megaherbivore (bison, Bison antiquus) and a large carnivore (dire wolf, Canis dirus) from the La Brea tar pits ( southern California, USA) and Great Basin (western USA). Contrary to previous expectations, we found that the environmental isotope pattern is better represented with increasing trophic level. Our results indicate that museum specimens of large carnivores would best reflect large-scale spatial and temporal patterns of carbon isotopes in the palaeontological record because top predators can act as ecological integrators of environmental change.

Parker, ET, Cleaves HJ, Bada JL, Fernandez FM.  2016.  Quantitation of alpha-hydroxy acids in complex prebiotic mixtures via liquid chromatography/tandem mass spectrometry. Rapid Communications in Mass Spectrometry. 30:2043-2051.   10.1002/rcm.7684   AbstractWebsite

RationaleSpark discharge experiments, like those performed by Stanley Miller in the 1950s, generate complex, analytically challenging mixtures that contain biopolymer building blocks. Recently, -amino acids and -hydroxy acids (AHAs) were subjected to environmental cycling to form simple depsipeptides (peptides with both amide and ester linkages). The synthesis of AHAs under possible primordial environments must be examined to better understand this chemistry. MethodsWe report a direct, quantitative method for AHAs using ultrahigh-performance liquid chromatography and triple quadrupole mass spectrometry. Hexylamine ion-pairing chromatography and selected reaction monitoring detection were combined for the rapid analysis of ten AHAs in a single run. Additionally, prebiotic simulation experiments, including the first-ever reproduction of Miller's 1958 cyanamide spark discharge experiment, were performed to evaluate AHA synthesis over a wide range of possible primitive terrestrial environments. ResultsThe quantitating transition for each of the AHAs targeted in this study produced a limit of detection in the nanomolar concentration range. For most species, a linear response over a range spanning two orders of magnitude was found. The AHAs glycolic acid, lactic acid, malic acid, and -hydroxyglutaric acid were detected in electric discharge experiments in the low micromolar concentration range. ConclusionsThe results of this work suggest that the most abundant building blocks available for prebiotic depsipeptide synthesis would have been glycolic, lactic, malic, and -hydroxyglutaric acids, and their corresponding amino acids, glycine, alanine, and aspartic and glutamic acids. Copyright (c) 2016 John Wiley & Sons, Ltd.

Ambler, RP, Bada JL, Finch P, Grocke DR, Eglinton G, Macko SA.  1999.  Preservation of key biomolecules in the fossil record: current knowledge and future challenges - Discussion. Philosophical Transactions of the Royal Society of London Series B-Biological Sciences. 354:86-87.Website
Parker, ET, Zhou MS, Burton AS, Glavin DP, Dworkin JP, Krishnamurthy R, Fernandez FM, Bada JL.  2014.  A plausible simultaneous synthesis of amino acids and simple peptides on the primordial earth. Angewandte Chemie-International Edition. 53:8132-8136.   10.1002/anie.201403683   AbstractWebsite

Following his seminal work in 1953, Stanley Miller conducted an experiment in 1958 to study the polymerization of amino acids under simulated early Earth conditions. In the experiment, Miller sparked a gas mixture of CH4, NH3, and H2O, while intermittently adding the plausible prebiotic condensing reagent cyanamide. For unknown reasons, an analysis of the samples was not reported. We analyzed the archived samples for amino acids, dipeptides, and diketopiperazines by liquid chromatography, ion mobility spectrometry, and mass spectrometry. A dozen amino acids, 10 glycine-containing dipeptides, and 3 glycine-containing diketopiperazines were detected. Miller's experiment was repeated and similar polymerization products were observed. Aqueous heating experiments indicate that Strecker synthesis intermediates play a key role in facilitating polymerization. These results highlight the potential importance of condensing reagents in generating diversity within the prebiotic chemical inventory.

Becker, L, Bada JL, Winans RE, Hunt JE, Bunch TE, French BM.  1994.  Fullerenes in the 1.85-Billion-Year-Old Sudbury Impact Structure. Science. 265:642-645.   10.1126/science.11536660   AbstractWebsite

Fullerenes (C-60 and C-70) have been identified by laser desorption, laser desorption postionization, and high-resolution electron-impact mass spectrometry in shock-produced breccias (Onaping Formation) of the Sudbury impact structure in Ontario, Canada, The C-60 isotope is present at a level of a few parts per million. The fullerenes were likely synthesized within the impact plume from the carbon contained in the bolide. The oxidation of the fullerenes during the 1.85 billion years of exposure was apparently prevented by the presence of sulfur in the form of sulfide-silicate complexes associated with the fullerenes.

Bennett, RV, Cleaves HJ, Davis JM, Sokolov DA, Orlando TM, Bada JL, Fernandez FM.  2013.  Desorption Electrospray Ionization Imaging Mass Spectrometry as a Tool for Investigating Model Prebiotic Reactions on Mineral Surfaces. Analytical Chemistry. 85:1276-1279.   10.1021/ac303202n   AbstractWebsite

Mineral-assisted thermal decomposition of formamide (HCONH2) is a heavily studied model prebiotic reaction that has offered valuable insights into the plausible pathways leading to the chemical building blocks of primordial informational polymers. To date, most efforts have focused on the analysis of formamide reaction products released in solution, although several studies have examined the role of mineral catalysts in promoting this chemistry. We show here that the direct investigation of reactive mineral surfaces by desorption electrospray ionization-mass spectrometry imaging (DESI-MSI) gives a new perspective on the important role of the mineral surface in the formation of reaction products. As a proof-of-principle example, we show that DESI-MSI allows interrogation of the molecular products produced on heterogeneous granite samples with minimal sample preparation. Purine and pyrimidine nucleobases and their derivatives are successfully detected by DESI-MSI, with a strong correlation of the spatial product distribution with the mineral microenvironment. To our knowledge, this study is the first application of DESI-MSI to the study of complex and porous mineral surfaces and their roles in chemical evolution. This DESI-MSI approach is generally applicable to a wide range of reactions or other processes involving minerals.

Bada, JL, Fegley B, Miller SL, Lazcano A, Cleaves HJ, Hazen RM, Chalmers J.  2007.  Debating evidence for the origin of life on Earth. Science. 315:937-938.Website
Parker, ET, Cleaves JH, Burton AS, Glavin DP, Dworkin JP, Zhou MS, Bada JL, Fernandez FM.  2014.  Conducting Miller-Urey experiments. Jove-Journal of Visualized Experiments.   10.3791/51039   AbstractWebsite

In 1953, Stanley Miller reported the production of biomolecules from simple gaseous starting materials, using an apparatus constructed to simulate the primordial Earth's atmosphere-ocean system. Miller introduced 200 ml of water, 100 mmHg of H-2, 200 mmHg of CH4, and 200 mmHg of NH3 into the apparatus, then subjected this mixture, under reflux, to an electric discharge for a week, while the water was simultaneously heated. The purpose of this manuscript is to provide the reader with a general experimental protocol that can be used to conduct a Miller-Urey type spark discharge experiment, using a simplified 3 L reaction flask. Since the experiment involves exposing inflammable gases to a high voltage electric discharge, it is worth highlighting important steps that reduce the risk of explosion. The general procedures described in this work can be extrapolated to design and conduct a wide variety of electric discharge experiments simulating primitive planetary environments.

Fang, LS, Bada JL.  1990.  The Blue-Green Blood-Plasma of Marine Fish. Comparative Biochemistry and Physiology B-Biochemistry & Molecular Biology. 97:37-45.   10.1016/0305-0491(90)90174-r   Website
Fang, LS, Bada JL.  1982.  Biliverdin Reductase-Activity in Marine Fishes. Marine Biology Letters. 3:121-130.Website