Linköping: self-assembly of proteins in inorganic solutions

Research lead

Researchers at Linköping University in Sweden have discovered a technique for persuading inactive peptides to form active proteins in inorganic solutions containing nanoscale silicon spheres. They say the method has applications in medical diagnostics, drug delivery and enzyme design.

Inorganic materials like silica are unwelcome in biological systems, since they disrupt the form and function of proteins. “We wanted to reverse the thinking and try to design proteins that take on their function only after encountering an inorganic surface,” says Bengt-Harald Jonsson, professor of molecular biotechnology at Linköping.

His team designed a peptide with a specific distribution of positive charges. This was mixed into a solution of spherical silica particles, about 9 nanometres in diameter. When the peptide was free in the solution it had no structure whatsoever, but when it encountered a negatively charged silica sphere it assumed the form of a helix. The result was a complex of a silica particle and a functional protein.