Researchers from Heddle Initiative Research Unit at RIKEN in Japan and Malopolska Centre of Biotechnology, Jagiellonian University in Poland created a nanoscale assemblage that could target the delivery of drugs to specific locations in the body. These structures called "protein cage" are durable and could withstand extreme conditions. They utilized shapes found in Islamic art.
The shape of dice has restrictions. A six-sided die will become distorted if the square faced will be replaced with triangles. There are also nano level isohedral structures that occur in nature. There are many tasks that these protein cages carry out and these are assembled from various protein subunits. An example are viruses whose protein cage carries viral genetic material into host cells.
Scientists aim to create artificial protein cages that have useful and novel properties. However, there are concerns that hinder this goal. The firs concern is in terms of geometry. Some proteins have a great potential but they cannot be accepted since they have the wrong shape. The second hindrance is complexity. Scientists find it difficult to to create complex networks that have weak chemical bonds that regulate protein-protein interactions.
"We were able to replace the complex interactions between proteins with simple 'staples' based on the coordination of single gold atoms." explains Professor Jonathan Heddle, the senior author of the research. "This simplifies the design problem and allows us to imbue the cages with new properties such as assembly and disassembly on demand."
The research has also found a way to get around the geometrical problem: "The building blocks of our protein cage are 11-membered rings." says Ali Malay, the first author of the paper, who is currently in the RIKEN Center for Sustainable Resource Science. "Mathematically speaking such shapes should be forbidden from forming symmetrical polyhedra." However, the researchers found that due to inherent flexibility, protein complexes can achieve previously unprecedented constructions based on near-perfect geometrical coincidences. "Previously proteins that were ignored because they had the 'wrong' shape can now be considered." says Malay.
The implications of the work are far-reaching, "What we, together with our collaborators have found, is simply the first step." says Heddle, who hopes that the work can be expanded further to produce cages with new structures and new capabilities and also investigated for potential applications particularly in drug delivery.
