Natural Product Disaccharide Engineering through Tandem Glycosyltransferase Catalysis Reversibility and Neoglycosylation

Abstract

A two-step strategy for disaccharide modulation using vancomycin as a model is reported. The strategy relies upon a glycosyltransferase-catalyzed ‘reverse’ reaction to enable the facile attachment of an alkoxyamine-bearing sugar to the vancomycin core. Neoglycosylation of the corresponding aglycon led to a novel set of vancomycin 1,6-disaccharide variants. While the in vitro antibacterial properties of corresponding vancomycin 1,6-disaccharide analogs were equipotent to the parent antibiotic, the chemoenzymatic method presented is expected to be broadly applicable.

Broadening the scope of glycosyltransferase-catalyzed sugar nucleotide synthesis

“…S13). This preliminary study indicates the Loki catalyst, in comparison with progenitors, to be not only a superior catalyst for sugar nucleotide synthesis but also superior as a potential catalyst for subsequent small molecule glycosylation (17,(39)(40)(41).…”

“…The impressive aglycon malleability of OleD (17)(18)(19), the demonstrated ability to expand the sugar scope of this catalyst, and the demonstrated superior ability of Loki to also catalyze "forward" coupled transglycosylation reactions suggest a range of exciting opportunities. Examples include extending applications toward (i) modified nucleoside-based NDPs (3) (reminiscent of the kinase "bump and hole" strategies) (38); (ii) specific sugardrug or sugar-natural product pairings (39)(40)(41); (iii) a broadened scope of deoxy, dideoxy, and/or uniquely functionalized sugars (e.g., sugars bearing amino-, N-akyl, O-alkyl, C-alkyl-, nitro, nitroso-, thio-modifications) (2,4,7,10,15,18,19); and (iv) other important biomolecules (e.g., proteins, polysaccharides) (42)(43)(44)(45).…”

OleD Loki as a Catalyst for Tertiary Amine and Hydroxamate Glycosylation

“…[9a, 13] Importantly, the use of 2-chloro-4-nitrophenyl (ClNP) glycoside donors in this context also offered a convenient colorimetric screen to enable the directed evolution of enhanced GTs with broad substrate permissivity and the identification of new GT substrates (Figure 1 A). [9a] Using ClNP-β- d -Glc and the OleD variant Loki, [9a] this colorimetric assay was applied to a panel of 28 representative aliphatic tertiary-amine-containing drugs (Figure S1 the Supporting Information).…”

Facile Chemoenzymatic Strategies for the Synthesis and Utilization of S‐Adenosyl‐L‐Methionine Analogues

“…[2] Such promiscuity is an enabling feature of chemoenzymatic NP diversification platforms as exemplified by NP glycorandomization (a platform for differential glycosylation of natural products/drugs). [3] Among the examples above, enzyme-catalyzed alkylation is a highly prevalent occurrence that leads to NP N -, O -, S - and/or C -alkylation (Figure 1). [4] Thus, a platform to co-opt natural product methyltransferases (MTs) for broad natural product differential alkylation (alkylrandomization) is anticipated to dramatically expand the potential scope of NP chemical diversity.…”

“…Finally, the strategy presented unveils a single vessel proof of concept for natural product ‘alkylrandomization’ which, while currently somewhat limited via enzyme specificity, is expected to be further advanced via MT/MAT directed evolution and/or structure-based engineering in a manner reminiscent to that used for advancing glycorandomization. [3,23] …”