SEOUL, South Korea, Sept. 28, 2017 /PRNewswire/ — Cells recognize external physical and chemical signals, and maintain their homeostasis by responding to these signals via reversibly* controlling the activity of signaling proteins. For example, the cell begins to divide when proteins involved in a cell cycle are activated, and after the division, the activity of these proteins are suppressed. If this reversible reaction is not properly regulated, the cell can be constantly being divided, causing diseases like cancer.
*Reversible reaction: a reaction that can proceed in either forward or inverse direction according to the reaction condition in a chemical reaction.
As such, most of the cellular process by enzymes occurring in the cell can be regulated as desired if the enzyme activity can be artificially and reversibly regulated. The most common method to manipulate the enzyme activity involves inserting the effector domain that can respond to the external physical and chemical stimuli (pH, temperature, light, etc.), but it can be used only when the structure and function of the relevant enzyme is properly understood.
The team led by Dr. So Yeon Kim of Center for Theragnosis in Biomedical Research Institute at Korea Institute of Science and Technology (KIST, President Byung Gwon Lee) has developed a DNA nanoswitch that can be used universally regardless of the structure and function of the enzyme that needs to be controlled. The team announced that they used a DNA nanostructure as a cage to encapsulate the enzyme of interest and have successfully controlled the enzyme activity artificially, reversibly and repeatedly.
The team at KIST designed the DNA sequence so that the desired enzyme is located inside of the tetrahedron-shaped DNA nanocage and inserted pH-sensitive sequence into one side of the tetrahedron. By doing so, they can control the enzyme accessibility to the surrounding environment via pH-dependent opening and closing of the DNA tetrahedron…