1. A Combinatoric Approach to the Study of Mineral- Molecule Interactions Frontiers in Mineral Science 2007 Session A15: Mineral-Molecule Interactions June 28, 2007 Robert Hazen, Geophysical Laboratory

2. Research Collaborators Carnegie Institution Hugh Churchill Jim Cleaves George Cody Gözen Ertem Tim Filley Rebecca Martin Jake Maule Andrew Steele George Washington Univ. Glenn Goodfriend Henry Teng University of Colorado Gifford Miller Steven DeVogel University of Arizona Robert T. Downs George Mason University Harold Morowitz Johns Hopkins University DimitriSverjensky Carnegie-Mellon University AravindAsthagiri David Sholl Smithsonian Institution Tim Gooding DetlefRost Ed Vicenzi Spanish Astrobiology Inst. Antonio Salgado-Serrano

3. Research Collaborators Carnegie Institution Hugh Churchill Jim Cleaves George Cody GözenErtem Tim Filley Rebecca Martin Jake Maule Andrew Steele George Washington Univ. Glenn Goodfriend Henry Teng University of Colorado Gifford Miller Steven DeVogel University of Arizona Robert T. Downs George Mason University Harold Morowitz Johns Hopkins University DimitriSverjensky Carnegie-Mellon University AravindAsthagiri David Sholl Smithsonian Institution Tim Gooding DetlefRost Ed Vicenzi Spanish Astrobiology Inst. Antonio Salgado-Serrano

4. Two Questions(Possibly Related) 1. How do crystals interact with organic molecules? 2. What processes selected life’s idiosyncratic molecules?

5. Origin of Biomolecules: The Problem A fundamental attribute of life is a high degree of molecular selectivity and organization, but prebiotic synthesis processes are indiscriminate. What prebiotic processes might have contributed to such selection and organization?

6. Biomolecular Selectivity:Amino Acids • Only 20 biological amino acids compared to >90 in Murchison meteorite • Only -H amino acids (i.e., no -methyl amino acids) • Homochirality – L >> R

7. 1 1 C C 4 4 2 2 3 3 (L)-enantiomer (R)-enantiomer Biological Homochirality Many of life’s essential molecules are chiral. How did life on Earth become homochiral? Annual sales of chiral pharmaceuticals approaches $200 billion.

8. Our Hypothesis: Minerals Work

9. Our Hypothesis: Minerals Work Aspartic acid on calcite Lysine on quartz TCA on calcite TCA on feldspar

10. Quartz – SiO2 Quartz is the only common chiral rock-forming mineral Right Left Reports of successful chiral selections as early as the 1930s. Yet all previous authors used powdered quartz!

11. Quartz: Face-Specific Adsorption (01-11) (10-11)

12. Quartz Crystal Faces Courtesy of S. Parker

13. Quartz – (100) Face

14. Quartz – (101) Face MIRROR

15. Quartz – (011) Face

16. Feldspar (110)

17. Feldspar (110)

18. Diopside – (110) Face

19. Diopside – (110) Face

20. Calcite – CaCO3

21. Calcite – (214) Face

22. Modeling Mineral-Molecule Interactions Begin by bringing a D-alanine molecule close to an unrelaxed calcite (214) surface.

23. D-Alanine-Calcite (214) Interactions The stable converged configuration reveals surface relaxation and Ca-O and O-H interactions, but no strong third interaction.

24. D-alanine L-alanine Alanine-Calcite (214) Interactions

25. Aspartic Acid-Calcite (214) Interactions (D)-ASP (L)-ASP The most stable configuration found for D- and L-aspartic acid on calcite (214) surface. The D enantiomer is favored by 8 Kcal/mol.

26. A General Research Strategy How do we evaluate interactions among the numerous possible mineral-molecule pairs? We need a combinatoric approach.

27. Jake Maule, Andrew Steele and Rebecca Martin

28. A Combinatoric Strategy • ChipWriter • Up to 126 minerals • Up to 49,152 spots per • mineral • Up to 96 different wells • 100-micron spots

29. Microarrays of Cy3-labeled asparagine, glutamine and tyrosine on glass at 20 serial dilutions. Each microarray was scanned simultaneously with 532nm/635nm lasers and the fluorescence emission was captured at the wavelength bands of 557-592nm (Cy3) and 650-690nm (Cy5). Each image shows the intensity of Cy3/Cy5 fluorescent bands at a focal distance of 60mm (left) and 120mm (right). A B C

30. Selective Adsorption on Minerals • ChipReader • Simultaneous analyses • of 105 spots. • D/L amino acid resolution • Excitation wavelengths at • 532 and 635 nm

31. A B Microarrays of Cy3-labeled L-lysine on left- and right-handed quartz (100) faces at 8 serial dilutions. 150-micron spots.

32. Tagged Lysine on Quartz Advances: We can print microarrays and observe differential adsorption on mineral surfaces. Problems: Fluorescent tags significantly modify the adsorption behavior. Most molecules of prebiotic interest are not fluorescent.

33. Edward Vicenzi and Detlef Rost ToF-SIMS Lab, Smithsonian Institution

34. Feldspar (010) in ToF-SIMS Sample Holder

35. ToF-SIMS High-resolution ion fragment maps of 150-micron L-lysine spots on calcite (214). X X

36. 300 AMU L lysine calcite C3H7+ C2H5N+ C2H3O+ 43Ca+ 42CaH+ m/Dm ~ 8000 FWHM L-Lysine on Calcite (214)

37. 9 x 13 Array on 1 x 1 x 0.3 cm feldspar plate.

38. AMINO ACIDS AND SUGARS ON FELDSPAR (010) Face – 1 x 1 cm plate

39. D-Lysine on Feldspar (010)

40. DL-Xylose on Feldspar (010)

41. 5 10 4 10 3 10 2 10 1 10 0 10 42.85 42.90 42.95 43.00 43.05 43.10 43.15 43.20 mass / u Mass vs. Intensity for ~43 mass unit fragments C2H3O (43.02) Key to Adsorbants ----- arabinose ----- lyxose ----- ribose ----- xylose ----- lysine C2H5N (43.04) Pentose Sugars Intensity Amino Acid

42. CONCLUSIONS • Many mineral surfaces have the potential for chiral selection of plausible prebiotic molecules. • Microarray technology coupled with ToF-SIMS provides a powerful experimental means for combinatoric studies of mineral-molecule interactions.

43. With thanks to: NASA Astrobiology Institute National Science Foundation Carnegie Institution of Washington