Natures wonders: spider silk magical strength (Introduction)

by David Turell @, Wednesday, October 24, 2018, 20:13 (389 days ago) @ David Turell

It depends on certain protein structures too complex for us to imitate:

https://www.washingtonpost.com/science/2018/10/22/secret-superstrong-webs-traced-tiny-s...

" A study published Monday in the Proceedings of the National Academy of Sciences reveals the building blocks of these fibers within the glands of black widow spiders, Latrodectus hesperus.

"The researchers observed that globs of proteins aggregate into never-before-seen complex structures. They’re tiny aggregations, some no more than 200 nanometers in diameter. But when spiders squeeze these teensy globs through their faucet-head-like nozzles, called spinnerets, at the base of their abdomen, the clumps become fibers that stretch for foot after foot.

“'Spider silk materials are better than any of the polymers we have in terms of their material properties,” said Gregory Holland, an analytical chemist at San Diego State University and one of the authors of the new report. These materials are “completely biodegradable,” he said, and have the potential to replace plastic “any place you see it.”

***

"Researchers predicted that silk proteins while floating loose in the spider glands might clump together in bubbles called micelles. The authors of the new report found something more complex. They described the structures as “nanoscale hierarchical assemblies.” Put another way, they found bubbles, as predicted, but the bubbles had clumped together in an unexpected fashion.

"Nature uses hierarchical assemblies all the time. Gianneschi offered a simplified example: “This would be almost like looking at a single petal on a flower. The single individual petals have structure, and they’re very interesting on their own, but when we see them in nature, we see them as an array.” If a micelle was a petal, the assembly was the flower.

"Currently, researchers can synthesize spider silk proteins, which are purified into a powder. These proteins are mixed with liquid, like adding water to cake mix. The trick is trying to spin the protein batter into fibers as strong as a spider’s.

"In early 2017, a team of researchers announced that it had created a process to spin long artificial spider silk fibers. The technique could produce strands a kilometer in length. Janne Johansson and Anna Rising, scientists at the Karolinska Institute in Sweden who helped develop the method, wrote a joint statement to The Washington Post to evaluate the research released this week: This study paints “a more detailed picture of how spider silk proteins” go from a dissolved substance in the glands to a fiber, Johansson and Rising said.

"Even with this study, scientists won’t be able to create better spider silk tomorrow. “But it will definitely provide models which the research community now can use to formulate new hypotheses for how to design [spider proteins] that can be produced in the laboratory and how to treat them and spin them,” Johansson and Rising said."

Comment: As usual nature is smarter than we are. This complex system certainly looks designed.


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