PMID: 13679061
Authors:
Filgueira de Azevedo W Jr, Canduri F, Marangoni dos Santos D, Pereira JH, Dias MV, Silva RG, Mendes MA, Basso LA, Palma MS, Santos DS
Title:
Structural basis for inhibition of human PNP by immucillin-H.
Journal:
Biochem Biophys Res Commun. 2003 Oct 3;309(4):917-22.
Abstract:
Purine nucleoside phosphorylase (PNP) catalyzes the phosphorolysis of the N-ribosidic bonds of purine nucleosides and deoxynucleosides. PNP is a target for inhibitor development aiming at T-cell immune response modulation. This work reports on the crystallographic study of the complex of human PNP-immucillin-H (HsPNP-ImmH) solved at 2.6A resolution using synchrotron radiation. Immucillin-H (ImmH) inhibits the growth of malignant T-cell lines in the presence of deoxyguanosine without affecting non-T-cell tumor lines. ImmH inhibits activated normal human T cells after antigenic stimulation in vitro. These biological effects of ImmH suggest that this agent may have utility in the treatment of certain human diseases characterized by abnormal T-cell growth or activation. This is the first structural report of human PNP complexed with immucillin-H. The comparison of the complex HsPNP-ImmH with recent crystallographic structures of human PNP explains the high specificity of immucillin-H for human PNP.