Asymmetric Sythesis of Unnatural L-Amino Acids Using Thermophilic Aromatic L-Amino Acid Transaminase

  • Cho, Byung-Kwan (School of Chemical and Biological Engineering and Institute of Molecular Biology and Genetics, Seoul National University) ;
  • Seo, Joo-Hyun (School of Chemical and Biological Engineering and Institute of Molecular Biology and Genetics, Seoul National University) ;
  • Kim, Ju-Han (School of Chemical and Biological Engineering and Institute of Molecular Biology and Genetics, Seoul National University) ;
  • Lee, Chang-Soo (Department of Chemical Engineering, Chungnam National University) ;
  • Kim, Byung-Gee (School of Chemical and Biological Engineering and Institute of Molecular Biology and Genetics, Seoul National University)
  • Published : 2006.08.30

Abstract

Aromatic L-amino acid transaminase is an enzyme that is able to transfer the amino group from L-glutamate to unnatural aromatic ${\alpha}-keto$ acids to generate ${\alpha}-ketoglutarate$ and unnatural aromatic L-amino acids, respectively. Enrichment culture was used to isolate thermophilic Bacillus sp. T30 expressing this enzyme for use in the synthesis of unnatural L-amino acids. The asymmetric syntheses of L-homophenylalanine and L-phenylglycine resulted in conversion yields of >95% and >93% from 150 mM 2-oxo-4-phenylbutyrate and phenylglyoxylate, respectively, using L-glutamate as an amino donor at $60^{\circ}C$. Synthesized L-homophenylalanine and L-phenylglycine were optically pure (>99% enantiomeric excess) and continuously pre-cipitated in the reaction solution due to their low solubility at the given reaction pH. While the solubility of the ${\alpha}-keto$ acid substrates is dependent on temperature, the solubility of the unnatural L-amino acid products is dependent on the reaction pH. As the solubility difference between substrate and product at the given reaction pH is therefore larger at higher temperature, the thermophilic transaminase was successfully used to shift the reaction equilibrium toward rapid product formation.

Keywords

References

  1. Taylor, P. P., D. P. Pantaleone, R. F. Senkpeil, and I. G. Fotheringham (1998) Novel biosynthetic approaches to the production of unnatural amino acids using transaminases. Trends Biotechnol. 16: 412-418 https://doi.org/10.1016/S0167-7799(98)01240-2
  2. Park, H. G., J. H. Do, and H. N. Chang (2003) Regioselective enzymatic acylation of multi-hydroxyl compounds in organic synthesis. Biotechnol. Bioprocess Eng. 8: 1-8 https://doi.org/10.1007/BF02932891
  3. Krapcho, J., C. Turk, D. W. Cushman, J. R. Powell, J. M. Deforrest, E. R. Spitzmiller, D. S. Karanewsky, M. Duggan, G. Rovansak, J. Schwartz, S. Natarajan, J. D. Godfrey, D. E. Ryono, R. Neubeck, K. S. Atwal, and E. W. Petrillo (1988) Angiotensin-converting enzyme inhibitors. Mercaptan, carboxyalkyl dipeptide, and phosphinic acid inhibitors incorporating 4-substituted prolines. J. Med. Chem. 31: 1148-1160 https://doi.org/10.1021/jm00401a014
  4. Lesson, P. A., X. Rabasseda, and J. Castaner (1997) FK-888. Drugs Future 22: 353-358
  5. Ager, D. J., I. G. Fotheringham, S. A. Laneman, D. P. Pantaleone, and P. P. Taylor (1997) The large scale synthesis of unnatural amino acids. Chim. Oggi. 15: 11-14
  6. Cho, B.-K., H. J. Cho, S.-H. Park, H. Yun, and B.-G. Kim (2003) Simultaneous synthesis of enantiomerically pure (S)-amino acids and (R)-amines using coupled transaminase reactions. Biotechnol. Bioeng. 81: 783-789 https://doi.org/10.1002/bit.10526
  7. Schulz, A., P. Taggeselle, D. Tripier, and K. Bartsch (1990) Stereospecific production of the herbicide phophinothricin (glufosinate) by transamination: isolation and characterization of a phosphinothricin-specific transaminase from Escherichia coli. Appl. Environ. Microbiol. 56: 1-6
  8. Meiwes, J., M. Schudok, and G. Kretzschmar (1997) Asymmetric synthesis of L-thienylalanines. Tetrahedron Asym. 8: 827-836
  9. Asano, Y., A. Yamada, Y. Kato, K. Yamaguchi, Y. Hibino, K. Hirai, and K. Kondo (1990) Enantioselective synthesis of (S)-amino acids by phenylalanine dehydrogenase from Bacillus sphaericus: use of natural and recombinant enzymes. J. Org. Chem. 55: 5567-5571 https://doi.org/10.1021/jo00308a012
  10. Xu, Q., G. Wang, X. Wang, T. Wu, X. Pan, A. S. C. Chan, and T. K. Yang (2000) The synthesis of L-(+)-homophenylalanine hydrochloride. Tetrahedron Asym. 11: 2309-2314 https://doi.org/10.1016/S0957-4166(00)00193-2
  11. Yang, Y. J., C. H. Lee, and Y. M. Koo (2004) Separation of amino acids by simulated moving bed using competitive Langmuir isotherm. Biotechnol. Bioprocess Eng. 9: 331- 338 https://doi.org/10.1007/BF02933053
  12. Ahn, J., J. Ryu, H. Jang, and J.-K. Jung (2004) Effect of growth rate on the production of L-proline in the fed-batch culture of Corynebacterium acetoacidophilum. Biotechnol. Bioprocess Eng. 9: 326-329 https://doi.org/10.1007/BF02942353
  13. Syldatk, C., D. Volkel, U. Bilitewski, K. Krohn, H. Hoke, and F. Wagner (1992) Biotechnological production of unnatural L-amino acids from D,L-5-monosubstituted hydantions. II. L-$\alpha$- and L-$\beta$-naphthylalanine. Biotechnol. Lett. 14: 105-110 https://doi.org/10.1007/BF01026234
  14. Cooper, A. J. L., J. Z. Ginos, and A. Meister (1983) Synthesis and properties of the $\beta$-keto acids. Chem. Rev. 83: 321-358 https://doi.org/10.1021/cr00055a004
  15. Cho, B. K., J. H. Seo, T. W. Kang, and B. G. Kim (2003) Asymmetric synthesis of L-homophenylalanine by equilibrium-shift using recombinant aromatic L-amino acid transaminase. Biotechnol. Bioeng. 83: 226-234 https://doi.org/10.1002/bit.10661
  16. Shin, J.-S. and B.-G. Kim (2002) Exploring the active site of amine: pyruvate aminotransferase on the basis of the substrate structure-reactivity relationship: How the enzyme controls substrate specificity and stereoselectivity. J. Org. Chem. 67: 2848-2853 https://doi.org/10.1021/jo016115i
  17. Peisach, D., D. M. Chipman, P. W. Van Ophem, J. M. Manning, and D. Ringe (1998) Crystallographic study of steps along the reaction pathway of D-amino acid aminotransferase. Biochemistry 37: 4958-4967 https://doi.org/10.1021/bi972884d
  18. Stewart, J. D. (2001) Dehydrogenases and transaminases in asymmetric synthesis. Curr. Opin. Chem. Biol. 5: 120-129 https://doi.org/10.1016/S1367-5931(00)00180-0
  19. Chao, Y. P., Z. J. Lai, P. Chen, and J. T. Chern (1999) Enhanced conversion rate of L-phenylalanine by coupling reactions of aminotransferases and phosphoenolpyruvate carboxykinase in Escherichia coli K-12. Biotechnol. Prog. 15: 453-458 https://doi.org/10.1021/bp990044f
  20. Fotheringham, I. G., N. Grinter, D. P. Pantaleone, R. F. Senkpeil, and P. P. Taylor (1999) Engineering of a novel biochemical pathway for the biosynthesis of L-2-aminobutyric acid in Escherichia coli K-12. Bioorg. Med. Chem. 7: 2209-2213 https://doi.org/10.1016/S0968-0896(99)00153-4
  21. Cho, B.-K., H. J. Cho, H. Yun, and B.-G. Kim (2003) Simultaneous synthesis of enantiomerically pure (S)- amino acids and (R)-amines using $\alpha$/$\beta$-aminotransferase coupling reactions with two-liquid phase reaction system. J. Mol. Catal., B Enzym. 26: 273-285 https://doi.org/10.1016/j.molcatb.2003.07.006
  22. Lo, H.-H., S.-K. Hsu, W.-D. Lin, N.-L. Chan, and W.-H. Hsu (2005) Asymmetrical synthesis of L-homophenylalanine using engineered Escherichia coli aspartate aminotransferase. Biotechnol. Prog. 21: 411-415 https://doi.org/10.1021/bp049756i
  23. Twomey, C. M. and S. Doonan (1997) A comparative study of the thermal inactivation of cytosol and mitochondrial aspartate aminotransferase. Biochim. Biophys. Acta 1342: 37-44
  24. Zale, S. E. and A. M. Klibanov (1983) On the role of reversible denaturation (unfolding) in the irreversible thermal inactivation of enzymes. Biotechnol. Bioeng. 25: 2221-2230 https://doi.org/10.1002/bit.260250908
  25. Cho, B.-K., H.-Y. Park, J.-H. Seo, K. Kinnera, B.-S. Lee, and B.-G. Kim (2004) Enzymatic resolution for the preparation of enantiomerically enriched D-$\beta$-heterocyclic alanine derivatives using Escherichia coli aromatic L-amino acid transaminase. Biotechnol. Bioeng. 88: 512-519 https://doi.org/10.1002/bit.20280