- SEAS researchers have found the chemical mechanism by which sure salt compounds break down protein waste, like wool and feathers.
- The invention allows a gentler and extra sustainable protein recycling course of.
The textile and meat-processing industries produce billions of tons of waste yearly within the type of feathers, wool and hair, all of that are wealthy in keratin – the robust, fibrous protein present in hair, pores and skin and nails.
Turning all that animal waste into helpful merchandise – from wound dressings to eco-friendly textiles to well being extracts – can be a boon for the atmosphere and for brand spanking new, sustainable industries. However upcycling proteins is difficult: Breaking down, or de-naturing, proteins into their element components sometimes requires corrosive chemical substances in giant, polluting amenities, preserving any cost-effective protocol out of attain.
Researchers within the Harvard John A. Paulson College of Engineering and Utilized Sciences (SEAS) have uncovered key basic chemistry of how proteins like keratin de-nature within the presence of sure salt compounds – an perception that might take protein recycling to the following stage.
A workforce led by Package Parker, the Tarr Household Professor of Bioengineering and Utilized Physics at SEAS, mixed experiments and molecular simulations to raised illuminate the chemical mechanisms by which salts trigger proteins to unfold. They’ve proven {that a} answer of concentrated lithium bromide, a salt compound recognized to interrupt aside keratin, interacts with the protein molecules in a very sudden means – not by binding to the proteins immediately, as was standard knowledge, however by altering the construction of the encircling water molecules to create a setting extra favorable for spontaneous protein unfolding.
This perception allowed the researchers to design a gentler, extra sustainable keratin extraction course of, separating the protein out of answer simply and with out the necessity for harsh chemical substances. The method can be reversed with the identical salt combination, enabling restoration and reuse of lithium bromide denaturants.
The analysis is revealed in Nature Communications and can also be featured in a Behind the Paper weblog put up.
Impressed by keratin biomaterials
First writer Yichong Wang, a graduate scholar in chemistry who works in Parker’s group, stated the analysis builds on the lab’s longstanding curiosity in creating keratin biomaterials with form reminiscence for biomedical functions. They’d beforehand noticed that keratin extracted from lithium bromide solvents can type thick, shapeable gels that readily separate from the encircling answer and solidify virtually instantly when positioned again in water. Whereas helpful, they discovered the conduct odd, and so they needed to grasp it higher.
“We thought there may be a spot between present mechanistic understanding of how de-naturation works, and what we had been seeing,” Wang stated. “That is once we received very within the mechanism itself to see if we may optimize our extraction procedures by explaining this phenomenon higher.”
Molecular dynamics reveals shifts in surrounding water
To dig deeper, the workforce turned to the lab of Professor Eugene Shakhnovich within the Division of Chemistry and Chemical Biology, whose experience is in protein biophysics. Molecular dynamics simulations led by co-author Junlang Liu allowed them to see that the lithium bromides weren’t engaged on the proteins in any respect, however somewhat, on the water round them.
It seems lithium bromide ions trigger water molecules to shift into two completely different populations – regular water, and water molecules that develop into trapped by the salt ions. As the traditional water quantity decreases, the proteins begin to unfold because of the thermodynamic shift within the atmosphere, somewhat than being immediately ripped aside like in different de-naturation strategies. “Making the water much less like water, permits the protein to unfold itself,” Wang stated. They’d comparable outcomes by testing easier proteins like fibronectin, pointing to a common mechanism.
Higher understanding and designing protein extraction strategies which are much less energy-intensive and fewer polluting than standard ones opens potential avenues for protein-upcycling industries. Within the Parker lab, utilizing keratin as a substrate for tissue engineering is a serious analysis thrust; having a dependable, sustainable methodology to extract and re-use such merchandise would bolster their efforts.
What’s extra, the method may lay a path for a complete new biomaterials business, turning a large waste stream like hair or rooster feathers into low-cost recycled supplies, presumably in its place for conventional plastics, for instance.
The analysis had many sources of federal assist, together with the Nationwide Institutes of Well being (R35GM139571 and R01EY030444) and the Nationwide Science Basis via the Harvard College Supplies Analysis Science and Engineering Heart (DMR-2011764). Different funding got here from the Well being@InnoHK program of the Innovation and Know-how Fee, a part of the Hong Kong SAR Authorities; and the Medical and Well being Informatics Laboratories at NTT Analysis, Inc.
