A – A + Spiders spin their silk from proteins and promises. The fibers are tough, flexible and environmentally friendly,…
Spiders spin their silk from proteins and promises. The fibers are tough, flexible and environmentally friendly, and entrepreneurs and researchers see them woven into a variety of products: spider silksuit, sweaters and even walkways. To get there, experts need to figure out what’s in the business. A study published in the Proceedings of the National Academy of Sciences reveals the building blocks of these fibers in the glands of black spiders, Latrodectus hesperus.
The researchers observed that the glob of proteins aggregated in previously-considered complex structures. They are small aggregates, some no more than 200 nanometers in diameter. But when the spiders pinch these teensy globs through their crane head-like nozzles, called the spinner’s, at the base of the abdomen, the lumps become fibers that extend for the foot after the foot.
“Spider silk material is 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 report. These materials are “completely biodegradable”, he says, and have the potential to replace plastic “any place you see it”.
Spider silk users have long tried to drive the spider to the spinning wheel. Pound for pound, spindle silk loops are harder than Kevlar, the material of bulletproof jackets. The problem is the scale. An 1
1-foot spider silk magazine, presented at New York’s US Natural History Museum in 2009, demanded four years, 80 weavers in Madagascar, one million gold sticks and about 500,000 dollars. In the early 2000s, a company bred transgenic goats that produced silk in its milk. It failed to deliver a consumer product and went bankrupt in 2009 (most of the spider crew was struck at the University of Utah Farm).
The Netherlands has worked with black widow spiders for years, and he believes that their silk is some of the strongest, even among spiders. Despite the lethal reputation of the black widows, the shy animals have not asked any of the 200 researchers and students who have passed their lab, he said.
The Netherlands recently collaborated with Northwestern University’s Nathan Gianneschi, who uses electron microscopes to study nanomaterials.
Researchers felt the makeup of the individual protein molecules in silk. And you and I can see long threads of spider silk. The place in the middle was a mystery. “There is this space between that knowledge and when we see a spider web,” said Gianneschi.
Together, the researchers and their colleagues used advanced imaging techniques to examine the silk proteins before they became fibers, within the black widow. Gianneschi and Holland credited two researchers, northwestern Lucas parent and David Onofrei on SDSU, with much of the job-intensive imaging work.
The Netherlands treats spider silk on an atomic atomic basis, using a technology called nuclear magnetic resonance, or NMR – the same principle behind an MRI machine. Gianneschi’s lab uses cryo-electron microscopy. Large molecules suspended in liquid are light-frozen in situ. This keeps the molecules and their natural form intact while researchers scan the samples with ultrapowerful microscopes. Three biophysics won the 2017 Nobel Prize in Chemistry to Develop Cryo-Electron Microscopy.
This work linked the two techniques. “We look at what we see at room temperature in NMR and what he sees after lightning, that’s the same to us,” Holland said.
Researchers predicted that silk proteins while floating loose in the spider glands could clump into bubbles called micelles. The authors of the report found something more complex. They described the structures as “nanoscale hierarchical assemblies”. Put on another way, they found bubbles as predicted, but the bubbles had clumbed unexpectedly.
Nature uses hierarchical assemblies all the time. Gianneschi offered a simplified example: “It would be almost like looking at a single petal of a flower. The individual petals have structure, and they are very interesting on their own, but when we see them in nature we see them as a matrix . “If a micelle was a petal, the parish was the flower.
The chain of events is something like this: A spider eats bytes and melts the food in the most basic parts, amino acids. The spider builds these amino acids into proteins, builds proteins in micelles, micelles in collections and compounds in fibers and pathways. And that process is reversible – spiders can eat their paths and reuse the amino acids in new silk ties.
Researchers can synthesize spider silk proteins, which are purified into a powder. These proteins are mixed with liquid, such as adding water to kakablanding. The trick tries to spin the protein film into fibers as strong as a spider.
In early 2017, a research group announced that it had created a process for spinning long synthetic spun fibers. The technology could produce strings one kilometer long. Janne Johansson and Anna Rising, a researcher at Karolinska Institutet in Sweden, who helped develop the method, wrote a joint statement to The Washington Post to evaluate the research released this week: This study shows “a more detailed picture of how spider silk proteins” goes from a dissolved substance into the glands to a fiber, said Johansson and Rising.
Even with this study, researchers will not be able to create better spider silks tomorrow. “But it will definitely provide models that the research group can now use to formulate new hypotheses for design [spider proteins] that can be produced in the laboratory and how to treat them and rotate them,” Johansson and Rising said.
The report offers Potential guidance on how to improve the artificial protein bit. The study authors plan to collaborate with those who have made synthetic spider silk protein powder to check whether the nano aggregates are present in the goopet. “We have just opened a new door to explore,” Holland said. 19659021] 21556521