Silk of Steel

Walking through a spider web is an irritating yet intriguing experience—the sticky texture yet surprising strength of the silk is fascinating. The molecular properties of spider silk make the fibers stronger than they appear. If millions of strands of spider silk assembled into a wire, it would be stronger than most man-made synthetic fibers. The Molecular Dissection of the Spider Silk Self-Assembly Process Creative Inquiry project, led by Dr. William R. Marcotte in the Department of Genetics and Biochemistry, works to understand and replicate the molecular properties of spider silk in order to one day replace non-renewable materials such as steel.

To understand silk strength, it is important to understand the process of silk creation. Silk glands in the spider’s abdomen host genes that code for the activation of specific enzymes and proteins that assemble the silk fiber. The Creative Inquiry project’s goal is to isolate one of the assembly proteins and determine its role in the making of silk fibers. The team hopes to determine if the protein is capable of functioning outside of the spider’s body. If so, this research could lead to the artificial manufacturing of spider silk in a laboratory.

As in many research groups, the team experienced some setbacks. They observed a perceived chemical block of an enzyme they were working with, but luckily, they identified the issue. “E. coli was putting the enzyme into what is called inclusion bodies, or insoluble particles, that make it very difficult to get an active enzyme,” Marcotte said. The team addressed the setback by altering the culture conditions to identify what was causing inclusion bodies to form. Many students were surprised when the initial procedure was not successful, but they worked hard to overcome this setback and were happy with the results.

The team learned the valuable lesson—that laboratory research requires persistence. In a research setting, the first try almost never yields expected results, and sometimes it takes years before a breakthrough discovery. Though Marcotte’s students experienced a taste of the frustration involved in research, they have also learned how to navigate setbacks. Producing spider silk in a lab may be years away, but the team is working hard to make this dream a reality. Someday, steel wire could be replaced by spider silk.