Engineered Biosynthesis of Gilvocarcin Analogues with Altered Deoxyhexopyranose Moieties

Enzymatic Total Synthesis of Defucogilvocarcin M and Its Implications for Gilvocarcin Biosynthesis

“…The chemical syntheses that have been developed so far are unsuitable for generating a library of analogues, [6] whereas combinatorial biosynthetic efforts have shown more promise. [7] The continued advancement and successful implementation of such combinatorial biosynthetic and mutasynthetic approaches requires an in-depth knowledge of the biosynthetic pathway. Incorporation studies with isotope-labeled precursors [8] and genetic experiments [1a, 8d, 9] have revealed that the benzo[ d ]naphtho[1,2- b ]pyran-6-one chromophore of the gilvocarcins is produced from a polyketide-derived angucyclinone intermediate through a complex oxidative rearrangement process.…”

“…[1a] The function of biosynthetic enzymes was then confirmed by both in vitro and in vivo studies. [7a, 9, 11–13] The cluster encodes a set of typical type II polyketide synthase (PKS) enzymes, which includes a ketosynthase (GilA), a chain-length factor (GilB), an acyl carrier protein (GilC), two malonyl-CoA:acyl carrier protein transacylase (MCAT) homologues (GilP, GilQ), a PKS-associated keto reductase (GilF), and two cyclases (GilK, GilG). Together, this group of enzymes was able to catalyze the formation of the angucy-clinone UWM6 ( 10 ).…”

“…[11] Considering that GilOI and GilOIV are oxygenases that contain flavin adenine dinucleotide (FAD, Figure S3 in the Supporting Information) and require their cofactor to be recycled, a reductase was needed to generate FADH 2 . The putative nicotinamide adenine dinucleotide (phosphate) (NAD(P)H) flavin reductase GilH [7a] showed only very poor activity. Therefore, the E. coli flavin reductase Fre, a readily available homologue of GilH with known functionality, was chosen and purified from an E. coli overexpression construct.…”

Analysis of carbohydrates and glycoconjugates by matrix‐assisted laser desorption/ionization mass spectrometry: An update for 2011–2012

“…Bleomycin analogues MALDI Synthesis of analogue with significantly improved DNA cleavage activity Gilvocarcin analogues TOF GilGT, the glycosyltransferase involved in C-glycosylation during gilvocarcin biosynthesis used to transfer other hexoses to gilvocarcin (Shepherd et al, 2011) Globotriose-chitosan conjugate Neomycine B (ring II) + peptide MALDI Strongly inhibits Tat-mediated transactivation of HIV-1 transcription (Das et al, 2012) Neomycin-neomycin dimer TOF High affinity for AT-rich DNA duplexes (Kumar et al, 2011b) Pyrimethamine solubilised with succinoglycan dimers TOF Dimers from Shinorhizobium meliloti Microarrays, quantum dots, nanoparticles etc. Blockwise alkylated tetrasaccharide-organic quantum dot complexes…”

Synthetic biological approaches to natural product biosynthesis

“…New glycosylated streptolydigin derivatives were generated, which implies that the glycosyltransferase has a certain degree of substrate flexibility toward deoxysugars and sets the stage for further engineering studies aimed at generating more potent analogs. Deoxyhexopyranose analogues of the antitumor antibiotic gilvocarcin were also engineered in a similar manner [36]. Gilvocarcin’s natural D-fucofuranose pathway was inactivated and genetically complemented with plasmids coding for neutral deoxysugars.…”