Low Energy Positron Interactions with Biological Molecules

ORAL

Abstract

There is some experimental evidence that positrons can produce distinctive molecular fragmentation patterns. It is known that tuning the incident positron energy to near resonance with molecule vibrations can strongly enhance the positron annihilation probability for a molecule. This suggests that fragmentation induced by slow positrons may provide valuable complementary information to existing techniques for identification and study of proteins. In order to study this concept, we are developing a general quantum method for reliably calculating the density distribution for positrons bound to large biological molecules using NEO/GAMESS. We find that the outer molecular orbitals as well as the higher p orbitals on the O atoms contribute heavily to the total annihilation rate. ~Using the basis sets and approximations we have tested to predict where annihilation occurs can ultimately help us understand the resulting fragmentation patterns of larger biological molecules.

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Authors

  • Indika Wanniarachchi

    Department of Physics and Astronomy, Wayne State University, Detroit, MI 48202 USA

  • Caroline Morgan

    Department of Physics and Astronomy, Wayne State University, Detroit, MI 48202 USA

  • Bernhard Schlegel

    Department of Chemistry, Wayne State University, Detroit, MI 48202 USA

  • Gary Kedziora

    DoD Supercomputing Resource Center (DSRC), Air Force Research Laboratory, 2435 Fifth Street, Bldg 676, Wright-Patterson Air Force Base, OH 45433 USA

  • Larry Burgrraf

    Air Force Institute of Technology, AFIT/ENP, 2950 Hobson Way, Wright-Patterson Air Force Base, OH 45433 USA

  • Oleg Popov

    Miami University, Chemistry Department, Penn State Univ., University Park, PA 16802, unaffiliated, Department of Materials Science and Engineering, Ohio State University Columbus, OH 43210, Department of Physics, Ohio State University, Columbus, OH 43210, Department of Physics and Astronomy, Wayne State University, Detroit, MI 48201, Korea Institute of Science and Technology, University of Cincinnati, Miami University of Ohio, University of Michigan, University of Notre Dame, University of Nebraska-Lincoln, Wayne State University, University of Tennessee, National Technical University of Athens, The University of Tennessee, Kettering Univeristy, University of Michigan-Dearborn, FNAL, Harvard University, California State University, Department of Physics, Kettering University, Flint, Michigan, Department of Natural Sciences, University of Michigan-Dearborn, Applied Sciences Inc., Cedarville, Ohio, Oakland University, University of Stockholm, Arizona State University

  • Oleg Popov

    Miami University, Chemistry Department, Penn State Univ., University Park, PA 16802, unaffiliated, Department of Materials Science and Engineering, Ohio State University Columbus, OH 43210, Department of Physics, Ohio State University, Columbus, OH 43210, Department of Physics and Astronomy, Wayne State University, Detroit, MI 48201, Korea Institute of Science and Technology, University of Cincinnati, Miami University of Ohio, University of Michigan, University of Notre Dame, University of Nebraska-Lincoln, Wayne State University, University of Tennessee, National Technical University of Athens, The University of Tennessee, Kettering Univeristy, University of Michigan-Dearborn, FNAL, Harvard University, California State University, Department of Physics, Kettering University, Flint, Michigan, Department of Natural Sciences, University of Michigan-Dearborn, Applied Sciences Inc., Cedarville, Ohio, Oakland University, University of Stockholm, Arizona State University