It is known that protein attachment to surfaces depends sensitively upon the local structure and environment of binding sites at nanometer scale. Using nanografting reversal nanografting, both atomic force microscopy (AFM)-based lithography techniques, with well-defined environments are designed engineered precision. Three proteins, goat antibiotin immunoglobulin G (IgG), lysozyme, rabbit G, immobilized onto these surfaces. Strong dependence on dimension spatial distribution revealed in...

The current consensus on characterization of NKT cells is based their reactivity to the synthetic glycolipid, α-galactosylceramide (α-GalCer) in a CD1d-dependent manner. Because limited availability α-GalCer, there constant search for CD1d-presented ligands that activate cells. α-anomericity carbohydrate considered be an important requisite CD1d-specific activation gram-negative, lipopolysaccharide-free bacterium Sphingomonas paucimobilis known contain glycosphingolipids (GSL) with...

ConspectusAlthough glycosyl iodides have been known for more than 100 years, it was not until the 21st century that their full potential began to be harnessed complex glycoconjugate synthesis. Mechanistic studies in late 1990s probed iodide formation by NMR spectroscopy and revealed important reactivity features embedded protecting-group stereoelectronics. Differentially protected sugars having an anomeric acetate were reacted with trimethylsilyl (TMSI) generate iodides. In absence of C-2...

The combination of reactive galactosyl iodide donors with electron-rich acceptor lipids provides highly stereoselective and efficient routes to α GalCer analogues. Using per-O-silylated donors, key intermediates can be obtained in a three-step, one-pot sequence providing useful constructs for analogue development.

Per-O-silylated galactosyl iodides undergo α-glycosidation with fully functionalized glycolipids producing biologically relevant conjugates.

Abstract A critical component of the host’s innate immune response involves lipid Ag presentation by CD1d molecules to NK T cells. In this study we used murine CD1d1-transfected L (L-CD1) cells effect viruses on CD1d-mediated NKT and found that an infection with vesicular stomatitis vaccinia (but not lymphocytic choriomeningitis) virus inhibited CD1d1-mediated presentation. This was under reciprocal control MAPKs, p38 ERK, due changes in intracellular trafficking CD1d1. The regulation MAPK...

Glycolipids containing α-linked galactosyl and glucosyl moieties have been shown to possess unique immunostimulatory activity creating a need for access diverse anomerically pure sources of these compounds immunological studies. To meet this demand, glycosyl iodides were enlisted in the synthesis biologically relevant glycoconjugates. In first-generation protocol, per-O-benzyl iodide was efficiently coupled with activated sphingosine acceptors, but fully functionalized ceramides found be...

The conversion of glycals to 2-deoxy glycosyl acetates followed by reaction with trimethylsilyl iodide affords the corresponding iodides, which readily undergo substitution aryl alkoxy anions provide 2-deoxy-β-O-aryl glycosides. Direct displacement anomeric alleviates need introduce temporary C-2 stereodirecting groups that require subsequent removal. only observable byproducts from glycosylations result elimination HI giving starting glycals, can be recycled through sequence.

As part of our continuing efforts to study the molecular events involved in HIV recognition mucosal membrane cells, we are studying interactions HIV-associated glycoprotein gp120, with cellular receptor GalCer. In this work, report investigations multivalent Au glyconanoparticles containing galactosyl and glucosyl headgroups recombinant gp120. These particles were prepared from disulfides C-glycosides linked triethylene glycol via an amide bond using a modification Brust method.1 Results...

Reported herein is a general method for the efficient syntheses of variety β-cyano glycosides through activation per-O-trimethylsilyl with TMSI to form α-glycosyl iodides, which undergo SN2-type displacement when treated tetrabutylammonium cyanide. The cyanoglycosides were reduced under mild conditions using NaBH4 in presence catalytic CoCl2(H2O)6 THF/H2O give corresponding aminomethyl glycosides.

Stereoselective synthesis of β-mannosides is one the most challenging linkages to achieve in carbohydrate chemistry. Both anomeric effect and C2 axial substituent favor formation glycoside (α-product). Herein, we describe mechanistic studies on β-selective glycosidation trimethylene oxide (TMO) using mannosyl iodides. Density functional calculations (at B3LYP/6-31+G(d,p):LANL2DZ level) suggest that both α- involve loose SN2-like transition-state structures with significant oxacarbenium...

Selective acetylation of various per-O-TMS-protected carbohydrates has been accomplished. Using a protecting group exchange strategy and microwave assistance, monosaccharides (glucose, galactose, mannose) can be selectively acetylated producing either the 6-O-monoacetate or 1,6-O-diacetylated species. This new class molecules deprotected without migration acetyl groups, providing useful synthetic intermediates. To demonstrate scope reaction, methodology was successfully extended to...

Integration of HIV-1 viral DNA into the host genome is carried out by HIV-integrase (IN) and a critical step in replication. Although several classes compounds have been reported to inhibit IN enzymatic assays, inhibition not always correlated with antiviral activity. Moreover, potent inhibitors such as chicoric acids do act upon intended target but behave entry instead. The charged nature contributes poor cellular uptake, these are further plagued rapid ester hydrolysis vivo. To address...

Abstract We have investigated the role of host's CD1d‐dependent innate antitumor immune response in a murine T‐cell lymphoma model vivo. found that C57BL/6 wildtype (WT) mice inoculated with RMA/S cells transfected CD1d1 died at same rate as vector‐transfected cells. In contrast, natural killer T (NKT) cell‐deficient CD1d or Jα18 knockout CD1d‐transfected survived significantly longer than cells, implicating involvement invariant NKT (iNKT) inhibiting activity vivo . contrast to mutant mice,...

Heterofunctional azide and alkyne PEG-linkers have been synthesized site specifically conjugated to scFv via a reactive thiol functionality; two were coupled by copper catalyzed 1,3-dipolar cycloaddition make divalent (di-scFv) with an inter-scFv distance defined provide binding; antigen binding was maintained for the di-scFv construct increased several times compared that of parent scFv; reaction reported herein represents important ligation strategy covalently link macromolecular proteins...

Vaccinia virus (VV) has been most commonly used as the vaccine to protect individuals against causative agent of smallpox (variola virus), but it also uses a number strategies meant evade or blunt host's antiviral immune response. Natural killer T (NKT) cells are subset immunoregulatory CD1d-restricted lymphocytes believed bridge innate and adaptive responses. It is shown here that VV-encoded molecules, B1R H5R, play role in ability VV inhibit CD1d-mediated antigen presentation NKT cells....

Chemical synthesis of a bacterial glycolipid BbGL1 is reported in two steps starting from per-O-TMS d-galactose. The key features are glycosyl iodide mediated β-stereoselective glycosylation the absence neighboring group participation and regioselective acylation.

<italic>Helicobacter pylori</italic>infects approximately half of the human population and is main cause various gastric diseases.