Biased Borate Esterification during Nucleoside Phosphorylase‐Catalyzed Reactions: Apparent Equilibrium Shifts and Kinetic Implications**

Abstract

Biocatalytic nucleoside (trans‐)glycosylations catalyzed by nucleoside phosphorylases have evolved into a practical and convenient approach to the preparation of modified nucleosides, which are important pharmaceuticals for the treatment of various cancers and viral infections. However, the obtained yields in these reactions are generally determined exclusively by the innate thermodynamic properties of the nucleosides involved, hampering the biocatalytic access to many sought‐after target nucleosides. We herein report an additional means for reaction engineering of these systems. We show how apparent equilibrium shifts in phosphorolysis and glycosylation reactions can be effected through entropically driven, biased esterification of nucleosides and ribosyl phosphates with inorganic borate. Our multifaceted analysis further describes the kinetic implications of this in situ reactant esterification for a model phosphorylase.

Nucleoside Phosphorylases make N7-xanthosine

“…During our ongoing efforts to facilitate nucleoside synthesis with NPs 14 – 16 , we serendipitously discovered N7X as an unexpected byproduct of a reaction cascade involving a bacterial purine NP and a guanine deaminase (see Supplementary Fig. 1 ).…”

A deamination-driven biocatalytic cascade for the synthesis of ribose-1-phosphate

“…As substrates for nucleoside phosphorylases (NPs), they additionally serve as valuable starting points for the enzymatic synthesis of nucleoside analogues, [1][2][3][4][5][6][7] one of the most successful classes of small-molecule drugs to treat viral infections 8,9 or cancer, 10,11 and which recently attracted interest as precursors of mRNA vaccines 12,13 and antibacterial agents. 14,15 Employing P1Ps for the synthesis of nucleoside analogues is especially advantageous when product yields are low due to thermodynamic constraints [16][17][18][19] or when suitable donor nucleosides are not readily available. 20,21 Despite its potential for the synthesis of important nucleoside analogues, a high-yielding and sustainable synthesis for P1Ps has not yet been developed.…”

“…NPs catalyse the tightly thermodynamically controlled reversible phosphorolytic cleavage of nucleosides to the corresponding nucleobases and P1Ps. [16][17][18] Previous NP-based routes toward Rib1P are mainly based on natural nucleosides [23][24][25][26][27] or the base-modified 7-methylguanosine (7-Me-Guo). 28,29 Using uridine as a substrate for Rib1P synthesis, isolated yields of only 31% and 25% were obtained using either E. coli UP 23 or thermostable pyrimidine NPs 24 (Figure 1, Top).…”

Quality Data from Messy Spectra: How Isometric Points Increase Information Content in Highly Overlapping Spectra

“…This creates a less than ideal situation for the wet lab practitioner who wishes to obtain the most amount of information from the simplest spectroscopic analysis possible. [4,5] What Are Isometric Points?…”