Exploration of a potential difluoromethyl-nucleoside substrate with the fluorinase enzyme

Abstract

Exploration of a potential difluoromethyl-nucleoside substrate with the fluorinase enzyme, Bioorganic Chemistry (2015), doi: http:// dx.doi.org/10.1016/j.bioorg. 2015.11.003 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. AbstractThe investigation of a difluoromethyl-bearing nucleoside with the fluorinase enzyme is described. 5',5'-Difluoro-5'-deoxyadenosine 7 (F 2 DA) was synthesised from adenosine, and found to bind to the fluorinase enzyme by isothermal titration calorimetry with similar affinity compared to 5'-fluoro-5'-deoxyadenosine 2 (FDA), the natural product of the enzymatic reaction. F 2 DA 7 was found, however, not to undergo the enzyme catalysed reaction with L-selenomethionine, unlike FDA 2, which undergoes reaction with L-selenomethionine to generate Se-adenosylselenomethionine. A co-crystal structure of the fluorinase and F 2 DA 7 and tartrate was solved to 1.8 Å, and revealed that the difluoromethyl group bridges interactions known to be essential for activation of fluoride for reaction. An unusual hydrogen bonding interaction between the hydrogen of the difluoromethyl group and one of the hydroxyl oxygens of the tartrate ligand was also observed. The bridging interactions, coupled with the inherently stronger C-F bond in the difluoromethyl group, offers an explanation for why no reaction is observed.

Halogenases for biosynthetic pathway engineering: Toward new routes to naturals and non-naturals

“…Along with lower turnover rates, the substrate scope of SAM-dependent halogenases are also limited to substrates SAM analogues, mainly 2-deoxy analogues. [47,48,202] This is often considered as one of the main reasons for not having many biosynthetic pathway engineering works reported with SAM-dependent halogenases. The fluorination chemistry in natural products, engineering fluorinases and applications of fluorinase enzymes are discussed elaborately in various recommended reviews.…”

Enzyme-catalyzed C–F bond formation and cleavage

“…In 2016, O'Hagan's group found that fluorinase can be applied to the synthesis of 5′,5′-Difluoro-5′-deoxyadenosine. (see Scheme 2; Thompson et al 2016). Some research has also been done on the recognition of substrates by fluorinase (Yeo et al 2017;Sun et al 2018).…”

S‐Adenosyl Methionine Cofactor Modifications Enhance the Biocatalytic Repertoire of Small Molecule C‐Alkylation

“…An earlier structural study of SalL in complex with ClDA and methoinine revealed a solvent-exposed channel into the active site. [38][39][40] To explore this in more detail, we obtained two structures of wild-type SalL with SAM and chloride (6RYZ, 1.50 Å), and with ClDA alone (6RZ2, 1.77 Å; Figure 2, Table S1). One significant difference in our structures compared to those obtained previously was a rotation of the sidechain of Arg243, from the solvent exposed exterior of the protein to the interior of the active site, enabling the formation of electrostatic interactions between Arg243 and the carboxylate of SAM (Figure 2, S1), and the side chain of Glu17 from the adjacent monomer.…”