The team has found an efficient method of harvesting purified protein molecules by altering an enzyme that soil bacteria use to break down their food. In its natural form, this enzyme would be of little use to drug developers, but the team has modified it so that it can be activated at the desired moment.
By creating essentially an "on-switch" for the enzyme's activity, the team has found a way to separate a single, desired protein from the mixture of thousands generated by a living cell, which remains biotechnology's natural protein factory of choice.
Bacteria use the enzyme, called subtilisin, as a sort of food processor: After producing it internally, they release the enzyme into the soil, where it uses a minuscule "blade" to chop up proteins into digestible pieces. Because it could damage the bacterium's interior, the blade has a protective sheath that only comes off once the enzyme has exited the cell.
"The enzyme and sheath are strongly attracted to each other. The enzyme's first act is to cut the sheath away," says NIST's Travis Gallagher. "The method takes advantage of their attraction in order to isolate the protein we want."
The team first creates many "sheathless" copies of the enzyme, which are modified to function only in the presence of a triggering molecule such as fluoride. The modified enzymes are bound to the surface of a strainer. Then the team uses engineered cells to generate mass quantities of a potentially therapeutic protein, each copy of which has a subtilisin sheath attached to it. After harvesting these proteins along with the thousands of others that grow in the cellular interior, they filter the mixture through the strainer, where the protein-sheath pairs are caught and stuck fast to the subtilisin while the rest of the mixture drains away.
At this point, the team flicks their switch. They add a bit of fluoride and the enzyme snips the bond between sheath and protein, releasing the desired protein free of almost all impurities. "The technique can conceivably be used to obtain any protein you like, and the process is repeatable, as the sheaths can be removed for another round of purification," Gallagher says. "For most proteins, the method can achieve greater than 95 percent purity at a single step."
The research team also includes members from Potomac Affinity Proteins, LLC (PAP) and the University of Maryland Biotechnology Institute (UMBI). UMBI holds the patent, which has been licensed to PAP. The research was supported by grants from the National Institutes of Health and the Bill and Melinda Gates Foundation.
Chad Boutin | Newswise Science News
First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife
Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie
Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.
This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...
Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion
Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...
Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.
"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...
In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.
A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...
By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.
"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...
14.10.2016 | Event News
14.10.2016 | Event News
12.10.2016 | Event News
25.10.2016 | Earth Sciences
25.10.2016 | Power and Electrical Engineering
25.10.2016 | Process Engineering