scholarly journals Can Crystal Symmetry and Packing Influence the Active Site Conformation of Homohexameric Purine Nucleoside Phosphorylases?

2016 ◽  
Vol 89 (2) ◽  
Author(s):  
Marija Luić ◽  
Zoran Štefanić
Keyword(s):  
Active Site ◽  
Crystal Symmetry ◽  
Purine Nucleoside ◽  
Nucleoside Phosphorylases ◽  
Active Site Conformation

Crystal structure of acetylxylan esterase from Caldanaerobacter subterraneus subsp. tengcongensis

2021 ◽  
Vol 77 (11) ◽  
Author(s):  
Kohei Sasamoto ◽  
Tomoki Himiyama ◽  
Kunihiko Moriyoshi ◽  
Takashi Ohmoto ◽  
Koichi Uegaki ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Cellulose Acetate ◽  
Electron Density ◽  
Active Site ◽  
Catalytic Domain ◽  
Crystal Packing ◽  
Signal Sequence ◽  
Industrial Applications ◽  
Side Chain ◽  
Active Site Conformation

The acetylxylan esterases (AXEs) classified into carbohydrate esterase family 4 (CE4) are metalloenzymes that catalyze the deacetylation of acetylated carbohydrates. AXE from Caldanaerobacter subterraneus subsp. tengcongensis (TTE0866), which belongs to CE4, is composed of three parts: a signal sequence (residues 1–22), an N-terminal region (NTR; residues 23–135) and a catalytic domain (residues 136–324). TTE0866 catalyzes the deacetylation of highly substituted cellulose acetate and is expected to be useful for industrial applications in the reuse of resources. In this study, the crystal structure of TTE0866 (residues 23–324) was successfully determined. The crystal diffracted to 1.9 Å resolution and belonged to space group I212121. The catalytic domain (residues 136–321) exhibited a (β/α)7-barrel topology. However, electron density was not observed for the NTR (residues 23–135). The crystal packing revealed the presence of an intermolecular space without observable electron density, indicating that the NTR occupies this space without a defined conformation or was truncated during the crystallization process. Although the active-site conformation of TTE0866 was found to be highly similar to those of other CE4 enzymes, the orientation of its Trp264 side chain near the active site was clearly distinct. The unique orientation of the Trp264 side chain formed a different-shaped cavity within TTE0866, which may contribute to its reactivity towards highly substituted cellulose acetate.

Interactions of Trimeric Purine Nucleoside Phosphorylases with Ground State Analogues — Calorimetric and Fluorimetric Studies

ChemInform ◽  
2004 ◽  
Vol 35 (9) ◽  
Author(s):  
Beata Wielgus-Kutrowska ◽  
Joachim Frank ◽  
Antonin Holy ◽  
Gertraud Koellner ◽  
Agnieszka Bzowska
Keyword(s):  
Ground State ◽  
Purine Nucleoside ◽  
Nucleoside Phosphorylases

Localization of purine and pyrimidine nucleoside phosphorylases in heart, kidney, and liver

1980 ◽  
Vol 239 (6) ◽  
pp. H721-H730 ◽  
Author(s):  
R. Rubio ◽  
R. M. Berne
Keyword(s):  
Guinea Pig ◽  
Kupffer Cells ◽  
Cellular Localization ◽  
Purine Nucleoside Phosphorylase ◽  
Degradation Products ◽  
Purine Nucleoside ◽  
Capillary Endothelium ◽  
Cell Fractionation ◽  
Nucleoside Phosphorylase ◽  
Nucleoside Phosphorylases

In isolated livers and kidneys perfused with Krebs-Henseleit solution, the relationship of the concentration of adenosine (Ado) to that of its degradation products inosine (Ino) and hypoxanthine (Hyp) in biliary, urinary, and venous effluents were determined. They revealed ratios of Hyp:Ado:Ino, 1.9:1:0.9, 0.7:1:0.6, and 1.3:1:0.5 for guinea pig biliary, guinea pig urinary, and rat urinary effluents, respectively, and their respective venous effluent were 58:1:29, 8.6:1:5.4, and 7.4:1:3.2. The greater proportion of Ino and Hyp in the venous effluents suggests active production in Ino and Hyp at the vessel wall. Purine nucleoside phosphorylase localization was determined histochemically and found most active in the cytoplasm of capillary endothelium and Kupffer cells. Thus, there is agreement between purine analysis and histochemical findings. The reliability of the histochemical technique was also tested by comparing activities of purine nucleoside phosphorylase (a cytoplasmic enzyme) and pyrmidine nucleoside phosphorylase (a nuclear enzyme) that catalyze similar reactions (nucleoside + inorganic phosphate in equilibrium base + ribose-1-phosphate) but with different base specificites and cellular localization, as indicated by cell fractionation studies. The histochemical results show that in contrast to the purine nucleoside phosphorylase, the pyrmidine specific enzyme was most active in the nuclei of endothelial and Kupffer cells. Thus, the technique discriminates between the two enzymes.

6-Methylpurine derived sugar modified nucleosides: Synthesis and evaluation of their substrate activity with purine nucleoside phosphorylases

2016 ◽  
Vol 65 ◽  
pp. 9-16 ◽  
Author(s):  
Abdalla E.A. Hassan ◽  
Reham A.I. Abou-Elkhair ◽  
William B. Parker ◽  
Paula W. Allan ◽  
John A. Secrist
Keyword(s):  
Modified Nucleosides ◽  
Purine Nucleoside ◽  
Nucleoside Phosphorylases

scholarly journals The structures of rnase a complexed with 3′-CMP and d(CpA): Active site conformation and conserved water molecules

1994 ◽  
Vol 3 (12) ◽  
pp. 2322-2339 ◽  
Author(s):  
Ingrid Zegers ◽  
Dominique Maes ◽  
Minh-Hoa Dao-Thi ◽  
Lode Wyns ◽  
Freddy Poortmans ◽  
...  
Keyword(s):  
Active Site ◽  
Rnase A ◽  
Water Molecules ◽  
Conserved Water Molecules ◽  
Active Site Conformation
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