Synthesis and biological evaluation of chemical tools for the study of Dolichol Linked Oligosaccharide Diphosphatase (DLODP)

Bacterial Lipid II Analogs: Novel In Vitro Substrates for Mammalian Oligosaccharyl Diphosphodolichol Diphosphatase (DLODP) Activities

“…Our previous results demonstrated that bacterial lipid II inhibits the cleavage of [ 3 H]DLO by microsomal DLODP [15], suggesting that bacterial lipids and their analogs may themselves be DLODP substrates. In order to examine the potential cleavage of bacterial lipid II by DLODP, we used fluorescent dansylated bacterial lipid II analogs (see Section 4).…”

“…Dansyl phospho-MurNAc-pentapeptide (M5P, see Table 1) was prepared by treatment of dansyl UDPM5 with nucleotide pyrophosphatase [26,27]. Solanesyl-based DLO analogs were synthesized as previously reported [15].…”

“…Due to environmental, expense, and time issues, these assays are not appropriate for high-throughput applications such as setting up genetic screens or monitoring column effluent. Our recent data demonstrate that lipid II, the precursor required for bacterial peptidoglycan biosynthesis [14], inhibits the Co 2+ -dependent generation of [ 3 H]OSP from [ 3 H]DLO [15] by human hepatocellular carcinoma HepG2 cell extracts. These data suggested that bacterial lipid II might be a potential in vitro substrate for DLODP and that dansylated lipid II analogs have the potential to be used as fluorescent substrates for the assay of mammalian and yeast DLODP activities.…”

Synthesis of Lipid-Linked Oligosaccharides (LLOs) and Their Phosphonate Analogues as Probes To Study Protein Glycosylation Enzymes

“…59 Scheme 7 Glycosyl α-phosphates 36, 15, or 18 by using electrophilic (a) chlorophosphate or (b) phosphoramidite sources with cyclic hemiacetals Gravier-Pelletier and co-workers recently reported that reaction of phosphites or phosphoramidites such as dibenzyl N,N-diethyl phosphoramidite with cyclic hemiacetal 21 and 37 in the presence of base, followed by phosphorus oxidation with hydrogen peroxide or mCPBA 63 yields GlcNAc and chitobiose α-dibenzyl phosphate 15 and 18 in 78% and 83% yield, respectively (Scheme 7, b). 64 In this case, again, the selectivity towards the α-anomer is explained by the presence of the NHAc group at C-2, destabilizing the formation of the β-anomer. The phosphoramidite strategy also allowed the preparation of Glc, GlcNAc, 60 Gulose, 63 and other more complex glycosyl phosphates.…”

Solid-Phase Modular Synthesis of Park Nucleotide and Lipids I and II Analogues

“…Thus, the reaction conditions were optimized using model substrates 23 and 24 24) in the solutionphase, and the results are summarized in Table 1. Treatment of 24 with uridine-5′-phosphorylmorphoridate 23 in the presChart 1.…”