Fighting bacteriophage infections

November 29, 2010

Wyatt Technology?s instruments are to be used by the Biological Macromolecules Joint Research Unit of the Université de Provence and Université de la Méditerranée in Marseille, France, to eliminate bacteriophage infections in dairy production.

Wyatt Technology’s instruments are to be used by the Biological Macromolecules Joint Research Unit of the Université de Provence and Université de la Méditerranée in Marseille, France, to eliminate bacteriophage infections in dairy production.

Lactococcus lactis is a widely used bacterium in dairy industry in the production of yoghurt and various cheeses. Several industrial strains are sensitive to bacteriophages, which can infect the bacterium and affect the finished product.

The first step of the infection process is the adsorption of the phage to the bacterial cell. One way to minimize infections is to competitively block phage adsorption by adding a protein that will bind to the phage before it reaches the cells. These proteins, inserted in a baseplate, mediate phages anchoring to their receptors on the host cell surface.

The Biological Macromolecules Joint Research Unit selected three Designed Ankyrin Repeat Proteins (DARPins) binding to the baseplate of the lactococcal phage. Both mass and stoichiometry of each DARPin were characterized using the company’s multi-angle light scattering (MALS), quasi-elastic light scattering (QELS) and refractometry instrumentation, coupled on-line with an analytical size exclusion chromatography (SEC) column.

As a result, the DARPins were found to constitute a potential tool to fight against phage and viral infections in general.

According to the company the results of the experiment showed the instrumentation allows the study of protein-protein complexes by monitoring complex formation and then accurately characterizing the size and stoichiometry of the resulting assembly.

An application note form the company, entitled “Lactococcus lactis Complex Characterization”, is available to download from www.wyatt.com