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Nature and position of functional group on thiopurine substrates influence activity of xanthine oxidase — Enzymatic reaction pathways of 6-mercaptopurine and 2-mercaptopurine are different

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Abstract

Xanthine oxidase-catalyzed hydroxylation reactions of the anticancer drug 6-mercaptopurine (6-MP) and its analog 2-mercaptopurine (2-MP) as well as 6-thioxanthine (6-TX) and 2-thioxanthine (2-TX) have been studied using UV-spectroscopy, high pressure liquid chromatography, photodiode array, and liquid chromatography-based mass spectral analysis. It is shown that 6-MP and 2-MP are oxidatively hydroxylated through different pathways. Enzymatic hydroxylation of 6-MP forms 6-thiouric acid in two steps involving 6-TX as the intermediate, whereas 2-MP is converted to 8-hydroxy-2-mercaptopurine as the expected end product in one step. Surprisingly, in contrast to the other thiopurines, enzymatic hydroxylation of 2-MP showed a unique hyperchromic effect at 264 nm as the reaction proceeded. However, when 2-TX is used as the substrate, it is hydroxylated to 2-thiouric acid. The enzymatic hydroxylation of 2-MP is considerably faster than that of 6-MP, while 6-TX and 2-TX show similar rates under identical reaction conditions. The reason why 2-MP is a better substrate than 6-MP and how the chemical nature and position of the functional groups present on the thiopurine substrates influence xanthine oxidase activity are discussed.

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Abbreviations

e− :

electron

2-MP:

2-mercaptopurine

6-MP:

6-mercaptopurine

8-OH-2-MP:

8-hydroxy-2-mercaptopurine

P max :

maximum level of product formed

PDA:

photodiode array

R t :

retention time

2-TX:

2-thioxanthine

6-TX:

6-thioxanthine

2-TUA:

2-thiouric acid

6-TUA:

6-thiouric acid

XOD:

xanthine oxidase

References

  1. Hille, R., and Nishino, T. (1995) FASEB J., 9, 995–1003.

    PubMed  CAS  Google Scholar 

  2. Escribano, J., Gracia-Canovas, F., and Gracia-Carmona, F. (1988) Biochem J., 254, 829–833.

    PubMed  CAS  Google Scholar 

  3. Ryan, M. G., Ratnam, K., and Hille, R. (1995) J. Biol. Chem., 270, 19209–19212.

    Article  PubMed  CAS  Google Scholar 

  4. Hille, R., Hagen, W. R., and Dunham, W. R. (1985) J. Biol. Chem., 260, 10569–10575.

    PubMed  CAS  Google Scholar 

  5. Hille, R. (1996) Chem. Rev., 96, 2757–2816.

    Article  PubMed  CAS  Google Scholar 

  6. Harris, C. M., Sanders, S. A., and Massey, V. (1999) J. Biol. Chem., 274, 4561–4569.

    Article  PubMed  CAS  Google Scholar 

  7. Hille, R. (1991) Biochemistry, 30, 8522–8529.

    Article  PubMed  CAS  Google Scholar 

  8. Porras, A. G., Olson, J. S., and Palmer, G. (1981) J. Biol. Chem., 256, 9096–9103.

    CAS  Google Scholar 

  9. Xia, M., Dempski, R., and Hille, R. (1999) J. Biol. Chem., 274, 3323–3330.

    Article  PubMed  CAS  Google Scholar 

  10. Kim, J. H., Ryan, M. G., Knaut, H., and Hille, R. (1996) J. Biol. Chem., 271, 6771–6780.

    Article  PubMed  CAS  Google Scholar 

  11. Rastelli, G., Castantino, L., and Albasini, A. (1997) J. Am. Chem. Soc., 119, 3007–3016.

    Article  CAS  Google Scholar 

  12. Zimm, S., Collins, J. M., O’Neill, D., Chabner, B. A., and Poplack, D. G. (1983) Clin. Pharmacol. Ther., 34, 810–817.

    Article  PubMed  CAS  Google Scholar 

  13. Relling, M. V., Hancock, M. L., Rivera, G. K., Sandlund, J. T., Ribeiro, R. C., Krynetski, E. Y., Pui, C., and Evans, W. E. (1999) J. Natl. Cancer Inst., 91, 2001–2008.

    Article  PubMed  CAS  Google Scholar 

  14. Venkatraman, G., Sharman, V. L., and Lee, H. A. (1990) J. Int. Med., 228, 69–71.

    Article  CAS  Google Scholar 

  15. Nakamura, M. (1991) J. Biochem., 110, 450–456.

    PubMed  CAS  Google Scholar 

  16. Tamta, H., Kalra, S., and Mukhopadhyay, A. K. (2005) Biochemistry (Moscow), 71, S49–S54.

    Article  CAS  Google Scholar 

  17. Tamta, H., Thilagavathi, R., Chakraborti, A. K., and Mukhopadhyay, A. K. (2005) J. Enz. Inh. Med. Chem., 20, 317–324.

    Article  CAS  Google Scholar 

  18. Tamta, H., Kalra, S., Anand, G. C. S., and Mukhopadhyay, A. K. (2005) J. Biol. Phys. Chem., 5, 89–99.

    CAS  Google Scholar 

  19. Hernandez, B., Orozco, M., and Luque, F. J. (1996) J. Comput.-Aided Mol. Design, 10, 535–544.

    Article  CAS  Google Scholar 

  20. Kim, J. H., Odutola, J. A., Popham, J., Jones, L., and Laven, S. (2001) J. Inorg. Biochem., 84, 145–150.

    Article  PubMed  CAS  Google Scholar 

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Authors and Affiliations

  1. Department of Biotechnology, National Institute of Pharmaceutical Education and Research, Sector 67, S.A.S Nagar, Punjab, India, 160062

    Hemlata Tamta, Sukirti Kalra & Anup K. Mukhopadhyay

  2. Department of Medicinal Chemistry, National Institute of Pharmaceutical Education and Research, Sector 67, S.A.S Nagar, Punjab, India, 160062

    Ramasamy Thilagavathi & Asit K. Chakraborti

Authors
  1. Hemlata Tamta
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  2. Sukirti Kalra
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  3. Ramasamy Thilagavathi
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  4. Asit K. Chakraborti
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  5. Anup K. Mukhopadhyay
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Correspondence to Hemlata Tamta.

Additional information

Published in Russian in Biokhimiya, 2007, Vol. 72, No. 2, pp. 203–211.

Originally published in Biochemistry (Moscow) On-Line Papers in Press, as Manuscript BM06-209, January 21, 2007.

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Tamta, H., Kalra, S., Thilagavathi, R. et al. Nature and position of functional group on thiopurine substrates influence activity of xanthine oxidase — Enzymatic reaction pathways of 6-mercaptopurine and 2-mercaptopurine are different. Biochemistry Moscow 72, 170–177 (2007). https://doi.org/10.1134/S000629790702006X

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  • DOI: https://doi.org/10.1134/S000629790702006X

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