Biochemists build largest synthetic molecular cage ever

UCLA biochemists have created the largest-ever protein that self-assembles into a molecular "cage." The research could lead to synthetic vaccines that protect people from the flu, HIV and other diseases.

At a size hundreds of times smaller than a human cell, it also could lead to new methods of delivering pharmaceuticals inside of cells, or to the creation of new nanoscale materials.

The protein assembly, which is shaped like a cube, was constructed from 24 copies of a protein designed in the laboratory of Todd Yeates, a UCLA professor of chemistry and biochemistry. It is porous -- more so than any other protein assembly ever created -- with large openings that would enable other large protein molecules to enter and exit.

Yeates, the study's senior author, has sought to build complex protein structures that self-assemble since he first published research on self-assembling proteins in 2001. In 2012, he and colleagues produced a self-assembling molecular cage made from 12 protein pieces combined perfectly like pieces of a puzzle. Now they have done so with 24 pieces, and they are currently attempting to design a molecular cage with 60 pieces. Building each larger protein presented new scientific challenges, but the bigger sizes could potentially carry more "cargo."

Yeates said that his lab's method also could lead to the production of synthetic vaccines that would mimic what a cell sees when it's infected by a virus. The vaccines would provoke a strong response from the body's immune system and perhaps provide better protection from diseases than traditional vaccines.