The effective force between two parallel DNA molecules is calculated as a function of their mutual separation for different valencies of counterion and salt ions and different salt concentrations. Computer simulations of the primitive model are used and the shape of the DNA molecules is accurately modeled using different geometrical shapes. We find that multivalent ions induce a significant att...

Materials that display multiple carbohydrate residues have gained much attention due to their potential to inhibit or modulate biological multivalent interactions. These materials can be grouped accordingly to the way they are prepared, as unimolecular or as self-assembled systems. Both systems take advantage of the fact that multivalent interactions have significantly higher binding affinity t...

The effect of specific immunoglobulin (Ig) on specific binding of antigen to cells has been studied in a model system consisting of nurine myeloma cells (MOPC 315), MOPC 315 serum, and DNP conjugates. MOPC 315 serum, which has IgA specific for DNP, specifically inhibited the binding of DNP conjugates to these cells. Using this model it was found that cells have a marked advantage over free spec...

The objective of this investigation is to engender greater confidence in the validity of binding equations derived for multivalent ligands on the basis of reacted-site probability theory. To that end, a demonstration of the theoretical interconnection between expressions derived by the classical stepwise equilibria and reacted-site probability approaches for univalent ligands is followed by the...

A theory is proposed which allows us to calculate the distribution of the multivalent counterions around a colloidal particle using the cell model. The results are compared with the Monte Carlo simulations and are found to be very accurate in the two asymptotic regimes, close to the colloidal particle and far from it. The theory allows to accurately calculate the osmotic pressure and the effect...

The inhibition of carbohydrate-protein interactions by tailored multivalent ligands is a powerful strategy for the treatment of many human diseases. Crucial for the success of this approach is an understanding of the molecular mechanisms as to how a binding enhancement of a multivalent ligand is achieved. We have synthesized a series of multivalent N-acetylglucosamine (GlcNAc) derivatives and s...

The present study demonstrates cation-driven optical properties of artificial luciferases (ALucs) from copepod luciferases, as an optical readout for bioanalysis. An assignment of the supersecondary structure code (SSC) of ALucs revealed that ALucs carry a helix-loop-helix structure, which appears at the same sites of the EF-hands of typical Ca(2+)-binding proteins. A mutagenesis study shows th...

Recurrent outbreaks of H5, H7 and H9 avian influenza viruses in domestic poultry accompanied by their occasional transmission to humans have highlighted the public health threat posed by these viruses. Newer vaccine approaches for pandemic preparedness against these viruses are needed, given the limitations of vaccines currently approved for H5N1 viruses in terms of their production timelines a...

A programmable pre-assembly method is described and shown to produce near-infrared fluorescent molecular probes with tunable multivalent binding properties. The modular assembly process threads one or two copies of a tetralactam macrocycle onto a fluorescent PEGylated squaraine scaffold containing a complementary number of docking stations. Appended to the macrocycle periphery are multiple copi...