The Role of Phosphate Binding in Purine Nucleoside Phosphorylase of Helicobacter pylori

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.

Comprehensive Analysis of Methyl-β-D-ribofuranoside: A Multifaceted Spectroscopic and Theoretical Approach

“…Examples like ribose and deoxyribose are integral components of RNA and DNA, respectively, shaping their three-dimensional structures and biological functions . Beyond nucleic acids, furanosides are crucial in antibiotics, antiviral drugs, and other biologically active compounds, impacting their efficacy and interactions . Moreover, furanosides offer a compelling platform for studying molecular recognition and binding processes fundamental to biochemical interactions. , The unique dynamics of furanose rings, including pseudo rotation and ring puckering, influences their behavior and interactions.…”