A group of researchers from the University of Oxford believe they have engineered a protein from flesh-eating bacteria that acts as a molecular `superglue` and could be used to help detect cancer cells.

"We`ve turned the tables and put one kind of flesh-eating bacterium to good use," said Mark Howarth, Ph.D., who led the research.

"We have engineered one of its proteins into a molecular superglue that adheres so tightly that the set-up we used to measure the strength actually broke. It resists high and low temperatures, acids and other harsh conditions and seals quickly.

"With this material we can lock proteins together in ways that could underpin better diagnostic tests - for early detection of cancer cells circulating in the blood, for instance. There are many uses in research, such as probing how the forces inside cells change the biochemistry and affect health and disease."

Howarth`s team at the University of Oxford in the United Kingdom genetically engineered the glue from a protein, FbaB, that helps Streptococcus pyogenes (S. pyogenes) bacteria infect cells. S. pyogenes is one of the microbes that can cause the rare necrotizing fasciitis, or flesh-eating bacteria syndrome, in which difficult-to-treat infections destroy body tissue.

They split FbaB into two parts, a larger protein and a smaller protein subunit, termed a peptide. Abbreviating S. pyogenes as "Spy," they named the small peptide "SpyTag" and the larger protein "SpyCatcher."

The gluing action occurs when SpyTag and SpyCatcher meet. They quickly lock together by forming one of the strongest possible chemical bonds. SpyCatcher and SpyTag can be attached to the millions of proteins in the human body and other living things, thus gluing proteins together.

One of the applications on the horizon involves testing the technology as a new way to detect "circulating tumor cells," or CTCs. Tumors shed these cells into the bloodstream, where they may act as seeds, spreading or metastasizing cancer from the original site to other parts of the body.

That spreading is the reason why cancer is such a serious health problem.

Howarth said that the Spy technology has advantages over other molecular gluing systems that are available. SpyCatcher and SpyTag, for instance, can glue two proteins together at any point in the protein.
"That flexibility allows us many different ways to label proteins and gives us new approaches to assemble proteins together for diagnostic tests," Howarth explained.

The study was recently presented at the 245th National Meeting and Exposition of the American Chemical Society.