{"73140":{"#nid":"73140","#data":{"type":"news","title":"New Test Boosts Search for Extraterrestrial Life","body":[{"value":"\u003Cp\u003EResearchers have identified a new test case that could be used for evaluating extraterrestrial samples for evidence of life. The new test could ultimately allow the use of simpler analytical instrumentation on future space missions.\n\u003C\/p\u003E\n\u003Cp\u003EIn the search for life on other planets, astrobiologists regard liquid water and chiral biomolecules to be critical components. \u0022Yet because chiral molecules can be made synthetically as well as biologically, it\u0027s not enough to just find them on other planets. We need to show a change of chirality over time,\u0022 said Tracey Thaler, a graduate student at Georgia Tech\u0027s School of Chemistry and Biochemistry. Thaler works with Professor Andreas Bommarius in the School of Chemical and Biomolecular Engineering.\n\u003C\/p\u003E\n\u003Cp\u003EThaler has investigated racemization - the conversion of an optically active compound to a racemic form, which has no optical rotation - as a new approach for analyzing samples in outer space. \u0022Because this type of reaction is found only in biological systems, it could serve as a marker for extraterrestrial life,\u0022 Thaler explained. She presented results from the study on Thursday, March 30, at the 231st American Chemical Society National Meeting in Atlanta. \n\u003C\/p\u003E\n\u003Cp\u003EThe study is part of a collaborative effort with Professor Rick Trebino\u0027s research group in Georgia Tech\u0027s School of Physics. The two research groups are trying to improve analytical instruments used on space missions, research that is sponsored by NASA.\n\u003C\/p\u003E\n\u003Cp\u003EChromatography, the current method used to evaluate extraterrestrial samples on space missions, is a tedious process, Bommarius explained. Another drawback, researchers must know in advance the specific compounds they\u0027re looking for, which isn\u0027t always possible. In contrast, polarimetry, a method for measuring optical activity, does not require knowledge of the structure being analyzed. But because existing polarimeters have performance limitations, Georgia Tech researchers are developing a more sensitive polarimeter that can detect smaller concentrations of optically active compounds. Thaler\u0027s work serves as a test bed for such an instrument.    \n\u003C\/p\u003E\n\u003Cp\u003E\u0022Tracey\u0027s study is significant because it marks the first time that racemization has been looked on as a sign of life on other planets,\u0022 Bommarius said. \u0022What\u0027s more, she has identified two new media in which the enzyme mandelate racemase is active.\u0022\n\u003C\/p\u003E\n\u003Cp\u003EMandelate racemase (MR) is an enzyme that catalyzes the racemization reaction for the substrate mandelic acid. Mandelate is one the simplest chiral molecules and has a large specific optical rotation, making it well-suited for polarization analysis, Thaler explained. \n\u003C\/p\u003E\n\u003Cp\u003EAn important part of the study was to determine if MR reactivity could occur at subzero temperatures found on planets like Mars or moons like Titan, Europa or Enceladus, where recent data shows water is likely to exist.  \n\u003C\/p\u003E\n\u003Cp\u003EAfter a number of unsuccessful attempts with organic cryosolvents - the most common medium to probe enzyme activity at low temperatures - Thaler achieved MR reactivity in two unconventional media. They were concentrated ammonium salt solutions and water-in-oil microemulsions (anionic surfactant Aerosol OT and non-ionic surfactant Triton X-100). Racemization occurred in temperatures as low as -30 degrees Celsius. This was promising because both the microemulsions and the concentrated salt solutions are expected to form on other planets and moons. \n\u003C\/p\u003E\n\u003Cp\u003EAnother auspicious finding: Measurements for the activation parameters (thermodynamics) in the ammonium salt solutions and water-in-oil microemulsions were very similar. \u0022This tells us that racemization is not only possible in other media, but thermodynamic parameters found in these media are similar to those found in media that\u0027s normally used,\u0022 Thaler said.  \n\u003C\/p\u003E\n\u003Cp\u003EThe next step will be to use the MR system with the new polarimeter being developed by Trebino\u0027s group while Thaler and other members of Bommarius\u0027 team explore additional  enzyme systems that might also be good test models.  \n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\nGeorgia Institute of Technology\u003Cbr \/\u003E\n75 Fifth Street, N.W., Suite 100\u003Cbr \/\u003E\nAtlanta, Georgia 30308 USA \u003C\/strong\u003E\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EMedia Relations Contacts\u003C\/strong\u003E: Jane Sanders (404-894-2214); E-mail: (\u003Ca href=\u0022mailto:jane.sanders@edi.gatech.edu\u0022\u003Ejane.sanders@edi.gatech.edu\u003C\/a\u003E) or John Toon (404-894-6986); E-mail: (\u003Ca href=\u0022mailto:jtoon@gatech.edu\u0022\u003Ejtoon@gatech.edu\u003C\/a\u003E)\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003ETechnical Contacts\u003C\/strong\u003E: Tracey Thaler (404-385-3089 or 404-388-5974); E-mail: (\u003Ca href=\u0022mailto:tracey.thaler@chbe.gatech.edu\u0022\u003Etracey.thaler@chbe.gatech.edu\u003C\/a\u003E) or Andreas Bommarius (404-385-1334); E-mail: (\u003Ca href=\u0022mailto:andreas.bommarius@chbe.gatech.edu\u0022\u003Eandreas.bommarius@chbe.gatech.edu\u003C\/a\u003E)\n\u003C\/p\u003E\n\u003Cp\u003E\u003Cstrong\u003EWriter\u003C\/strong\u003E:  T.J. Becker\n\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":[{"value":"Novel chemical reaction could serve as marker for life and simplify space instrumentation"}],"field_summary":[{"value":"Researchers have identified a new test case that could be used for evaluating extraterrestrial samples for evidence of life. The new test could ultimately allow the use of simpler analytical instrumentation on future space missions.","format":"limited_html"}],"field_summary_sentence":[{"value":"A new test could help spot extraterrestrial life"}],"uid":"27303","created_gmt":"2006-03-30 01:00:00","changed_gmt":"2016-10-08 03:03:34","author":"John Toon","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2006-03-30T00:00:00-05:00","iso_date":"2006-03-30T00:00:00-05:00","tz":"America\/New_York"},"extras":[],"hg_media":{"73141":{"id":"73141","type":"image","title":"Europa","body":null,"created":"1449177979","gmt_created":"2015-12-03 21:26:19","changed":"1475894671","gmt_changed":"2016-10-08 02:44:31"}},"media_ids":["73141"],"related_links":[{"url":"http:\/\/www.che.gatech.edu\/fac_staff\/faculty\/bommarius.php","title":"Andreas Bommarius"},{"url":"http:\/\/www.che.gatech.edu\/","title":"School of Chemical and Biomolecular Engineering"},{"url":"http:\/\/www.chemistry.gatech.edu\/","title":"School of Chemistry and Biochemistry"}],"groups":[{"id":"1188","name":"Research Horizons"}],"categories":[],"keywords":[],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cstrong\u003EJohn Toon\u003C\/strong\u003E\u003Cbr \/\u003EResearch News \u0026amp; Publications Office\u003Cbr \/\u003E\u003Ca href=\u0022http:\/\/www.gatech.edu\/contact\/index.html?id=jt7\u0022\u003EContact John Toon\u003C\/a\u003E\u003Cbr \/\u003E\u003Cstrong\u003E404-894-6986\u003C\/strong\u003E","format":"limited_html"}],"email":["jtoon@gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}