Defining criteria for oligomannose immunogens for HIV using icosahedral virus capsid scaffolds.

The broadly neutralizing antibody 2G12 recognizes a conserved cluster of high-mannose glycans on the surface envelope spike of HIV, suggesting that the "glycan shield" defense of the virus can be breached and may, under the right circumstances, serve as a vaccine target. In an attempt to recreate features of the glycan shield semisynthetically, oligomannosides were coupled to surface lysines on the icosahedral capsids of bacteriophage Q beta and cowpea mosaic virus (CPMV). The Q beta glycoconjugates, but not CPMV, presented oligomannose clusters that bind the antibody 2G12 with high affinity.

Measurement of monovalent and polyvalent carbohydrate-lectin binding by back-scattering interferometry.

Carbohydrate-protein binding is important to many areas of biochemistry. Here, backscattering interferometry (BSI) has been shown to be a convenient and sensitive method for obtaining quantitative information about the strengths and selectivities of such interactions. The surfaces of glass microfluidic channels were covalently modified with extravidin, to which biotinylated lectins were subsequently attached by incubation and washing.

On-virus construction of polyvalent glycan ligands for cell-surface receptors.

Glycans arrayed on the exterior of virus particles were used as substrates for glycosyltransferase reactions to build di- and trisaccharides from the virus surface. The resulting particles exhibited tight and specific associations with cognate receptors on beads and cells, in one example defeating in cis cell-surface interactions in a manner characteristic of polyvalent binding. Combined with the ability of viruses to provide structurally well-defined attachment points, the methodology provides a convenient and powerful way to prepare complex carbohydrate ligands for clustered receptors.

Anti-carbohydrate antibodies elicited by polyvalent display on a viral scaffold.

Tetra- and hexasaccharides were arrayed on the exterior surface of cowpea mosaic virus by using a copper-catalyzed azide-alkyne cycloaddition reaction. Inoculation of chickens with these virus conjugates gave rise to large quantities of polyclonal anti-glycan IgY antibodies that displayed excellent avidity and specificity on analysis with printed glycan microarrays. Avian IgY antibodies are produced in significantly higher yield than is possible for mouse or rabbit IgG, and exhibit reduced cross reactivity with native mammalian proteins.

Multivalent, bifunctional dendrimers prepared by click chemistry.

Unsymmetrical dendrimers, containing both mannose binding units and coumarin fluorescent units, have been prepared using click chemistry and shown to be highly efficient, dual-purpose recognition/detection agents for the inhibition of hemagglutination.

"Clickable" agarose for affinity chromatography.

Successful purification of biological molecules by affinity chromatography requires the attachment of desired ligands to biocompatible chromatographic supports. The Cu(I)-catalyzed cycloaddition of azides and alkynes-the premier example of "click chemistry"-is an efficient way to make covalent connections among diverse molecules and materials. Both azide and alkyne units are highly selective in their reactivity, being inert to most chemical functionalities and stable to wide ranges of solvent, temperature, and pH.

Virus-glycopolymer conjugates by copper(I) catalysis of atom transfer radical polymerization and azide-alkyne cycloaddition.

The Cu(I)-catalyzed ATRP and azide-alkyne cycloaddition reactions together provide a versatile method for the synthesis of end-functionalized glycopolymers and their attachment to a suitably modified viral protein scaffold.

Aldolase antibody activation of prodrugs of potent aldehyde-containing cytotoxics for selective chemotherapy.

Prodrugs of potent aldehyde analogues of the anticancer drug doxorubicin (Dox) were synthesized. These prodrugs were efficiently activated by antibody 93F3 and no drug formation was observed in the absence of 93F3 in either phosphate buffered saline or cell culture media. In the presence of antibody 93F3, these prodrugs were activated and decreased the proliferation of human cancer cells in in vitro proliferation assays.

Natural supramolecular building blocks. Wild-type cowpea mosaic virus.

Cowpea mosaic virus (CPMV) can be isolated in gram quantities, possesses a structure that is known to atomic resolution, and is quite stable. It is therefore of potential use as a molecular entity in synthesis, particularly as a building block on the nanochemical scale. CPMV was found to possess a lysine residue with enhanced reactivity in each asymmetric unit, and thus 60 such lysines per virus particle.