Croatica Chemica Acta, Vol. 91 No. 2, 2018.
Original scientific paper
https://doi.org/10.5562/cca3335
The Role of Phosphate Binding in Purine Nucleoside Phosphorylase of Helicobacter pylori
Marta Bošnjaković
; Division of Physical Chemistry, Ruđer Bošković Institute, POB 180, HR-10002 Zagreb, Croatia
Ivana Leščić Ašler
; Division of Physical Chemistry, Ruđer Bošković Institute, POB 180, HR-10002 Zagreb, Croatia
Zoran Štefanić
orcid.org/0000-0002-3486-4291
; Division of Physical Chemistry, Ruđer Bošković Institute, POB 180, HR-10002 Zagreb, Croatia
Abstract
Purine nucleoside phosphorylase (PNP) is an essential enzyme in the purine salvage pathway of Helicobacter pylori. Since H. pylori lacks the ability to synthesize purine nucleosides de novo, inhibition of this enzyme could stop the growth of this bacterium. However, for the design of successful inhibitors the details of the mechanism of this enzyme should be fully understood. PNPs catalyze cleavage of the glycosidic bond of purine nucleosides, and phosphate is one of the substrates. It is thought that binding of phosphate induces the conformational change as a necessary initial step in the catalysis. This conformational change is manifested in closing of either one of the six active sites in the homohexameric PNPs. It is unclear whether the binding of phosphate is sufficient or just a necessary condition for the closing of the active site. In this paper we conducted an experiment to check this by soaking the crystals of the apo form of the enzyme in increasing concentrations of phosphate.
This work is licensed under a Creative Commons Attribution 4.0 International License.
Keywords
active site conformation; enzyme catalysis; purine nucleoside phosphorylase; phosphate binding
Hrčak ID:
202329
URI
Publication date:
4.6.2018.
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