Synthesis of pseudo-disaccharide analogues of lipid A: haptens for the generation of antibodies with glycosidase activity towards lipid A

Bio-organic Synthesi

Synthesis of glycosylated 1-deoxynojirimycins starting from natural and synthetic disaccharides

Iminosugars are an important class of natural products and have been subject to extensive studies in organic synthesis, bioorganic chemistry and medicinal chemistry, yet only a limited number of these studies are on glycosylated iminosugars. Here, a general route of synthesis is presented towards glycosylated 1‐deoxynojirimycin derivatives based on the oxidation–reductive amination protocol that in the past has also been shown to be a versatile route towards 1‐deoxynojirimycin. The strategy can be applied on commercial disaccharides, as shown in four examples, as well as on disaccharides that are not commercially available and are synthesized for this purpose, as shown by a fifth example.Medical BiochemistryBio-organic Synthesi

Ortho-Carborane-modified N-substituted Deoxynojirimycins

Medical Biochemistr

Two-step activity-based protein profiling of diacylglycerol lipase

Diacylglycerol lipases (DAGL) produce the endocannabinoid 2-arachidonoylglycerol, a key modulator of neurotransmitter release. Chemical tools that visualize endogenous DAGL activity are desired. Here, we report the design, synthesis and application of a triazole urea probe for DAGL equipped with a norbornene as a biorthogonal handle. The activity and selectivity of the probe was assessed with activity-based protein profiling. This probe was potent against endogenous DAGLα (IC50 = 5 nM) and it was successfully applied as a two-step activity-based probe for labeling of DAGLα using an inverse electron-demand Diels–Alder ligation in living cells.Bio-organic SynthesisMolecular Physiolog

Chemical proteomics reveals antibiotic targets of oxadiazolones in MRSA

Molecular PhysiologyBio-organic Synthesi

A chemical genetic screen reveals that iminosugar inhibitors of plant glucosylceramide synthase inhibit root growth in Arabidopsis and cereals

Bio-organic SynthesisMedical Biochemistr

Synthesis of a panel of carbon-13-labelled (glyco)sphingolipids

Medical Biochemistr

Role of β-glucosidase 2 in aberrant glycosphingolipid metabolism: model of glucocerebrosidase deficiency in zebrafish

β-glucosidases (GBA1 [glucocerebrosidase], GBA2, and GBA3) are ubiquitous, essential enzymes. Lysosomal GBA1 and cytosol-facing GBA2 degrade glucosylceramide (GlcCer); GBA1 deficiency causes Gaucher disease (GD), a lysosomal storage disorder characterized by lysosomal accumulation of GlcCer, which is partly converted to glucosylsphingosine (GlcSph). GBA1 and GBA2 also may transfer glucose from GlcCer to cholesterol, yielding glucosylated cholesterol (GlcChol). Here, we aimed to clarify the role of zebrafish Gba2 in glycosphingolipid metabolism during Gba1 deficiency in zebrafish (Danio rerio), which are able to survive total Gba1 deficiency. We developed Gba1 and Gba2 zebrafish knockouts (gba1-/- and gba2-/-, respectively) using CRISPR/Cas9, modulated glucosidases genetically and pharmacologically, studied GlcCer metabolism in individual larvae, and explored the feasibility of pharmacologic or genetic interventions. Activity-based probes and quantification of relevant glycolipid metabolites confirmed enzyme deficiency. GlcSph increased in gba1-/- larvae (0.09 pmol/fish) but did not increase more in gba1-/-:gba2-/- larvae. GlcCer was comparable in gba1-/- and wild-type (WT) larvae but increased in gba2-/- and gba1-/-:gba2-/- larvae. Independent of Gba1 status, GlcChol was low in all gba2-/- larvae (0.05 vs. 0.18. pmol/fish in WT). Pharmacologic inactivation of zebrafish Gba1 comparably increased GlcSph. Inhibition of glucosylceramide synthase in Gba1-deficient larvae reduced GlcCer and GlcSph, and concomitant inhibition of glucosylceramide synthase and Gba2 with iminosugars also reduced excessive GlcChol. Finally, overexpression of human GBA1 and injection of recombinant GBA1 both decreased GlcSph. We determined that zebrafish  larvae offer an attractive model to study glucosidase actions in glycosphingolipid metabolism in vivo, and we identified distinguishing characteristics of zebrafish Gba2 deficiency. Animal science

ChemInform Abstract: Synthesis of Pseudo-Disaccharide Analogues of Lipid A: Haptens for the Generation of Antibodies with Glycosidase Activity Towards Lipid A.

Bio-organic Synthesi