Denaturation-resistant bifunctional colloidal superstructures assembled via the proteinaceous barnase-barstar interface.

To date, a number of biomolecule-mediated nanoparticle self-assembly systems have been developed that are amenable to controllable disassembly under relatively gentle conditions. However, for some applications such as design of self-assembled multifunctional theragnostic agents, high stability of the assembled structures can be of primary importance. Here, we report extraordinarily high durability of protein-assisted nanoparticle self-assembly systems yielding bifunctional colloidal superstructures resistant to extreme denaturing conditions intolerable for most proteins (e.

Expression of humanized anti-Her2/neu single-chain IgG1-like antibody in mammary glands of transgenic mice.

A system for production of single-chain antibody in mammary glands of mice was developed on the basis of a hybrid gene constructed from the coding sequence of anti-Her2/neu single-chain antibody inserted into the first exon of the sheep beta-lactoglobulin gene. Lines of transgenic mice were obtained that expressed humanized single-chain anti-Her2/neu IgG1-like antibody in their milk. These antibodies interact with Her2/neu antigen with high affinity (K(d) = 0.

Protein-assisted self-assembly of multifunctional nanoparticles.

A bioengineering method for self-assembly of multifunctional superstructures with in-advance programmable properties has been proposed. The method employs two unique proteins, barnase and barstar, to rapidly join the structural components together directly in water solutions. The properties of the superstructures can be designed on demand by linking different agents of various sizes and chemical nature, designated for specific goals.