Pico-World of Molecular Bioscavengers, Mops and Sponges Being Designed

Protein molecule 'dragnets' were designed on computers and built in a lab to recognize and unite with small molecules.

Computer-designed proteins that can recognize and interact with small biological molecules are now a reality. Scientists have succeeded in creating a protein molecule that can be programmed to unite with three different steroids. The achievement could have far wider ranging applications in medicine and other fields, according to the Protein Design Institute at the University of Washington.

"This is major step toward building proteins for use as biosensors or molecular sponges, or in synthetic biology -- giving organisms new tools to perform a task," said one of the lead researchers, Christine E. Tinberg, a postdoctoral fellow in biochemistry at the UW.

The scientific team overcame previously unsolved problems in building accurate protein-small molecule interfaces. Earlier attempts struggled with discrepancies between the computer plans and the structures of the actual molecules. In conducting the study, the researchers learned general principles for engineering small molecule-binding proteins with strong attraction energies. Their findings open up the possibility that binding proteins could be created for many medical, industrial and environmental uses.

In medical diagnostics, for example, a rationally programmed protein might detect biomolecules found only in a specific disease state, such as an early-stage cancer. Other types of protein molecules might eventually be manufactured to treat an overdose or to block a poison. Remediation possibilities for these molecular workhorses could include trapping pollutants or capturing waste.