for National Geographic Channel
Scientists hope to soon be able to spin spider silk without the aid of spidersachieving an age-old human quest to harness one of nature's most remarkable materials.
Randy Lewis is a professor of molecular biology at the University of Wyoming in Laramie. His team of researchers has successfully sequenced genes related to spider-silk productionuncovering the formula that spiders use to make silk from proteins. In the process the team acquired a better understanding of how the silk's structure is related to its amazing strength and elastic properties.
Their next task will be using what they've learned to spin spider silk themselves.
"Hopefully in the next month we'll start spinning fibers," Lewis told National Geographic News.
Scientists don't completely understand how spiders spin liquid protein into solid fibers. With their spinnerets, spiders somehow apply physical force to rearrange the proteins' molecular structure to turn the proteins into silk.
Understanding how spiders do this could someday result in new stronger and lighter materials that could replace plasticsand ease the cost to the environment that results from conventional plastic production. But duplicating spider silk in the lab has proven difficult.
Cracking the Code
By cracking the genetic code of spider silk, scientists hope not only to be able to duplicate the material but perhaps even to improve on it.
"We're trying to alter both the strength and elasticity of the natural silks," Lewis said. "We've made a number of different synthetic genes based on what we found in natural silksbut altered in ways to make them even stronger and more flexible. We're really trying to control elasticity, so you if come to me and ask for a certain tensile strength and elasticity, I can make a gene that will produce a fiber that does that for you."
Thomas Scheibel, from the department of chemistry at the Technical University of Munich, Germany, is engaged in similar types of "protein engineering." He recently published a review of his work in the journal Microbial Cell Factories.
"We're now not only after the uniqueness of the silk thread but the uniqueness of the single molecular building blocks within that thread," he said.
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