Purine nucleoside phosphorylase (PNP) catalyzes the phosphorolysis of the N-ribosidic bonds of purine nucleosides and deoxynucleosides. In human, PNP is the only route for degradation of deoxyguanosine and genetic deficiency of this enzyme leads to profound T-cell mediated immunosuppression ...
Purine nucleoside phosphorylase (PNP) catalyzes the phosphorolysis of the N-ribosidic bonds of purine nucleosides and deoxynucleosides. In human, PNP is the only route for degradation of deoxyguanosine and genetic deficiency of this enzyme leads to profound T-cell mediated immunosuppression. PNP is therefore a target for inhibitor development aiming at T-cell immune response modulation and its low resolution structure has been used for drug design. Here we report the structure of human PNP solved to 2.3A resolution using synchrotron radiation and cryocrystallographic techniques. This structure allowed a more precise analysis of the active site, generating a more reliable model for substrate binding. The higher resolution data allowed the identification of water molecules in the active site, which suggests binding partners for potential ligands. Furthermore, the present structure may be used in the new structure-based design of PNP inhibitors.
Related Citations:
Application of Crystallographic and Modeling Methods in the Design of Purine Nucleoside Phosphorylase Inhibitors Ealick, S.E., Babu, Y.S., Bugg, C.E., Erion, M.D., Guida, W.C., Montgomery, J.A., Secrist, J.A.3rd. (1991) Proc Natl Acad Sci U S A 88: 11540
Organizational Affiliation:
Departamento de Física, UNESP, São José do Rio Preto, SP, Brazil. walterfa@df.ibilce.unesp.br
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