Purine nucleoside phosphorylases (PNP): three-dimensional structure and molecular mechanism of catalysis

Crystal structure of the purine nucleoside phosphorylase from Cellulomonas sp. with phosphate and 8-Iodoguanine

People involved
Agnieszka Bzowska
Beata Wielgus-Kutrowska
Marta Narczyk

Collaboration with (in Department of Biophysics)
Jan Antosiewicz
Anna Modrak-Wójcik

Keywords
purine nucleoside phosphorylases
mechanism of catalysis
kinetics
crystallography
spectroscopy

Research interests

Enzymes catalyse virtually all of the chemical reactions in living organisms. Determination of the three-dimensional structure of enzymes at atomic resolution and elucidation of molecular mechanisms of catalysis, and interactions with ligands, is a challenging scientific problem, and in many cases has also important practical applications. Such enzymes are, amongst others, purine nucleoside phosphorylases. Their potent selective inhibitors are potential immunosuppressive (in organ transplantation and therapy of leukaemia) and antiparasitic agents, while differences in specificities between phosphorylases from human and other sources, e.g. E. coli, can be used in gene therapy against some tumours (see Bzowska et al., 2000). We try to determine structures and mechanisms of enzymes from this family, using X-ray diffraction, enzyme kinetics, spectroscopy and calorimetric methods.

Selected publications

  1. A. Bzowska, M. Luić, W. Schröder, D. Shugar, W. Saenger and G. Koellner, Calf spleen purine nucleoside phosphorylase: purification, sequence and crystal structure of its complex with N(7)-acycloguanosine inhibitor, FEBS Letters 367, 214-218 (1995).
  2. A. Bzowska, E. Kulikowska, N. E. Poopeiko and D. Shugar, Kinetics of 3-(ż-D-ribofuranosyl)adenine and 3-(ż-D-ribofuranosyl)hypoxanthine, non-conventional substrates of purine nucleoside phosphorylase, Eur. J. Biochem. 239, 229-234 (1996).
  3. G. Koellner, M. Luić, D. Shugar, W. Saenger and A. Bzowska, Crystal structure of calf spleen purine nucleoside phosphorylase in a complex with hypoxanthine at 2.15 ż resolution, J. Mol. Biol. 265, 202-216 (1997).
  4. G. Koellner, M. Luić, D. Shugar, W. Saenger and A. Bzowska, Crystal structure of the ternary complex of E. coli purine nucleoside phosphorylase with formycin B, a structural analogue of the substrate inosine, and phosphate (sulphate) at 2.1 ż resolution, J. Mol. Biol. 280, 153-166 (1998).
  5. E. Kulikowska, A. Bzowska, A. Holy, L. Magnowska and D. Shugar, Antiviral acyclic nucleoside phosphonate analogues as inhibitors of purine nucleoside phosphorylase, Adv. Exp. Med. Biol. 431, 747-752 (1998).
  6. J. Tebbe, A. Bzowska, B. Wielgus-Kutrowska, W. Schröder, Z. Kazimierczuk, D. Shugar, W. Saenger, W. and G. Koellner, Crystal structure of purine nucleoside phosphorylase (PNP) from Cellulomonas sp. and its implications of the molecular mechanism of trimeric PNPs, J. Mol. Biol. 294, 1239-1255 (1999).
  7. A. Bzowska, E. Kulikowska and D. Shugar, Purine nucleoside phosphorylase: properties, functions and clinical aspects, Pharm. Ther. 88: 349-425 (2000).
  8. M. Luić, G. Koellner, D. Shugar, W. Saenger and A. Bzowska, Calf spleen purine nucleoside phosphorylase: structure of its ternary complex with an N(7)-acycloguanosine inhibitor and a phosphate anion, Acta Cryst. D57, 30-36 (2001).
  9. G. Koellner, A. Bzowska, B. Wielgus-Kutrowska, M. Luić, T. Steiner, W. Saenger and J. Stępiński, 'Open' and 'closed' conformation of the E. coli purine nucleoside phosphorylase active center and implications for the catalytic mechanism, J. Mol. Biol. 315, 351-371 (2002).
  10. A. Bzowska, Calf spleen purine nucleoside phosphorylase: complex kinetic mechanism, hydrolysis of 7-methylguanosine, and oligomeric state solution, Biochim. Biophys. Acta 1596, 293-317 (2002).

Supported by

Ministry of Science and Higher Education:

"Homooligomeric enzymes with very strong cooperation in ligands binding" (project leader Dr. Agnieszka Bzowska, 2010-2013)

"Mechanism of binding of ligands and communication between purine nucleoside phosphorylase subunits - investigations of mutants with changed fluorescence properties" (project leader Dr. Agnieszka Bzowska, 2008-2009)