Nucleoside Phosphorylases Make N7-Xanthosine, the “Non-native” Regioisomer of Xanthosine

2023/10/25 by Sarah Westarp, Felix Brandt, Lena Neumair +7 · 1 voice
Biochemistry, Genetics and Molecular Biology · Medicine · #Adenosine and Purinergic Signaling #Biochemical and Molecular Research #HIV/AIDS drug development and treatment

paper · pdf · doi:10.26434/chemrxiv-2023-0fp1b

openalex publication_date 2023/10/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/14

Abstract

Modern, highly evolved, nucleoside-processing enzymes are known to exhibit perfect regioselectivity over the glycosylation of purine nucleobases at N9. We herein report an exception to this paradigm. Wild-type nucleoside phosphorylases also furnish N7- xanthosine, the “non-native” ribosylation regioisomer of xanthosine. This unusual nucleoside possesses several atypical physicochemical properties such as redshifted absorption spectra, a high equilibrium constant of phosphorolysis and low acidity. Ultimately, the biosynthesis of this previously unknown natural product illustrates how even highly evolved, essential enzymes from the primary metabolism are imperfect catalysts.

Citations

• UV-Spectroscopic Detection of (Pyro-)Phosphate with the PUB Module
• Biased Borate Esterification during Nucleoside Phosphorylase‐Catalyzed Reactions: Apparent Equilibrium Shifts and Kinetic Implications**
• Purine nucleoside phosphorylases: properties, functions, and clinical aspects

Discussions

• Aaah I do think this was an actual human 🤔 Their comments were reflected, critical, constructive and insightful. But hey you can be the judge of that when the manuscript (doi.org/10.26434/che...) app [bsky, 1 points, 1 comments]

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