Cellulose is a tough, fibrous material that is found in all plants. It is the most abundant organic compound on Earth, and it is a potential source of renewable energy. However, cellulose is difficult to break down into sugars, which is necessary for it to be used as a biofuel.
Enzymes called cellulases break down cellulose into sugars. However, cellulases are often inefficient, and they can be slowed down by molecular roadblocks. These roadblocks can include the presence of other molecules, such as lignin, that interfere with the cellulases' ability to bind to cellulose.
The researchers at UC Berkeley used a technique called X-ray crystallography to study the structure of cellulases in detail. They found that the cellulases were able to bind to cellulose in two different ways. One way was a strong, productive binding that allowed the cellulases to break down the cellulose. The other way was a weak, unproductive binding that prevented the cellulases from breaking down the cellulose.
The researchers also found that the unproductive binding was more likely to occur when there were other molecules present that interfered with the cellulases' ability to bind to cellulose. This suggests that the molecular roadblocks that slow down cellulases are caused by the presence of other molecules.
The researchers' findings could lead to new ways to engineer cellulases that are more efficient at breaking down cellulose. This could make biofuels more affordable and sustainable.
"Our findings provide a new understanding of how cellulases work and how they are inhibited by molecular roadblocks," said lead researcher Daniel Rokhsar. "This knowledge could lead to the development of new enzymes that are more efficient at breaking down cellulose, which would make biofuels more affordable and sustainable."
