Biomotor Breakthrough is Monthly Publication Highlight
Sep 26, 2013
Scientists at the University of Kentucky have cracked a 35-year-old mystery about the workings of natural "biomotors." These molecular machines serve as models for the development of synthetic nanomotors that may someday pump therapeutic DNA, RNA or drugs into individual diseased cells.
The recent report that revealed the innermost mechanisms of these motors in a bacteria-killing virus and that described a "new way to move DNA through cells," has been named the UK College of Pharmacy Publication Highlight for September. The article, "Mechanism of One-Way Traffic of Hexameric Phi29 DNA Packaging Motor with Four Electropositive Relaying Layers Facilitating Anti-Parallel Revolution," was published in ACS Nano and can be downloaded at http://pubs.acs.org/doi/abs/10.1021/nn4002775.
Peixuan Guo, Professor in the UK College of Pharmacy's Department of Pharmaceutical Sciences and holds the William S. Farish Fund Endowed Chair in Nanobiotechnology for the Markey Cancer Center, and his colleagues explain that two motors have been found in nature: A linear motor and a rotating motor. Now, Guo’s laboratory reports the discovery of a third type, a revolving molecular motor.
Guo points out that nanomotors will open the door to practical machines and other nanotechnology devices so small that 100,000 of them would fit across the width of a human hair. One major natural prototype for his development efforts has been the motor that packages DNA into the shell of bacteriophage phi29, a virus that infects and kills bacteria.
Guo’s research team wants to embed a synthetic version of that motor into nanomedical devices that are injected into the human body, travel to diseased cells and pump in medication. A major barrier in doing so has been uncertainty and controversy about exactly how the phi29 motor moves. Scientists thought that it worked by rotating or spinning in the same motion as the Earth turning once every 24 hours upon its own axis.
In their ACS Nano paper, Guo — with his team including Zhengyi Zhao, Emil Khisamutdinov, and Chad Schwartz — challenge that idea. Indeed, they discovered that the phi29 motor moves DNA without any rotational motion. The motor moves DNA with a revolution similar to the Earth revolving around the sun in one orbit every 365 days. The "revolution without rotation" model could resolve a big conundrum troubling the past 35 years of painstaking investigation of the mechanism of these viral DNA packaging motors, the report states.