Navigation Links
Biochemical 'on-switch' could solve protein purification challenge

Drugs based on engineered proteins represent a new frontier for pharmaceutical makers. Even after they discover a protein that may form the basis of the next wonder drug, however, they have to confront a long-standing problem: how to produce large quantities of the protein in a highly pure state. Now, a multi-institutional research team including a biochemist at the National Institute of Standards and Technology (NIST) may have found* a new solution in an enzymatic "food processor" they can activate at will.

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."


Contact: Chad Boutin
National Institute of Standards and Technology (NIST)

Related biology news :

1. Developer of advanced computing memory, father of biochemical engineering, and innovative engineering educators win highest engineering honors of 2009
2. UT Southwestern researchers disrupt biochemical system involved in cancer, degenerative disease
3. Margarita Saenz, M.D. is recipient of Genzyme/ACMGF Fellowship in Biochemical Genetics
4. Kelvin Lee winner of Biochemical Engineering Journal Young Investigator Award
5. Newly created cancer stem cells could aid breast cancer research
6. Obesity and lack of exercise could enhance the risk of pancreatic cancer
7. Finding that 1-in-a-billion that could lead to disease
8. 60 second test could help early diagnosis of common brain diseases
9. Auto immune response creates barrier to fertility; could be a step in speciation
10. Paracetamol, one of most used analgesics, could slow down bone growth
11. Drug could improve pregnancy outcomes in wider range of women with insulin resistance
Post Your Comments:
Related Image:
Biochemical 'on-switch' could solve protein purification challenge
(Date:11/18/2015)... new scientific discoveries deepen our understanding of how cancer ... challenges in better using that knowledge to guide treatment ... children continue to survive pediatric cancer, that counseling may ... John M. Maris, M.D ., a pediatric oncologist ... --> John M. Maris, M.D ., ...
(Date:11/17/2015)... Paris from 17 th until ... from 17 th until 19 th November ... has invented the first combined scanner in the world which scans ... Until now two different scanners were required: one for passports ... on the same surface. This innovation is an ideal solution ...
(Date:11/17/2015)... Nov. 17, 2015  Vigilant Solutions announces today that ... Board of Directors. --> ... retiring from the partnership at TPG Capital, one of ... over $140 Billion in revenue.  He founded and led ... the TPG companies, from 1997 to 2013.  In his ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... ... 2015 , ... The United States Golf Association (USGA) today announced Dr. Bruce ... Presented annually since 1961, the USGA Green Section Award recognizes an individual’s distinguished service ... , Clarke, of Iselin, N.J., is an extension specialist of turfgrass pathology in the ...
(Date:11/24/2015)... Nov. 24, 2015 /CNW/ - iCo Therapeutics ("iCo" or ... financial results for the quarter ended September 30, ... Canadian dollars and presented under International Financial Reporting ... ," said Andrew Rae , President ... iCo-008 are not only value enriching for this ...
(Date:11/24/2015)... QUEBEC CITY , Nov. 24, 2015 /PRNewswire/ - ... the request of IIROC on behalf of the Toronto ... this news release there are no corporate developments that ... price. --> --> ... --> . --> Aeterna Zentaris ...
(Date:11/24/2015)... ... 2015 , ... This fall, global software solutions leader SAP and AdVenture Capital ... and pitch their BIG ideas to improve health and wellness in their schools. , ... win the title of SAP's Teen Innovator, an all-expenses paid trip to Super Bowl ...
Breaking Biology Technology: