New method of recycling proteins receives patent

A new technique that rejuvenates expired or inactive proteins at a significantly higher rate than other methods has received U.S. patent protection. We're told it can cut production costs 30% for food enzymes. Chemists at Central Michigan University (Mount Pleasant, MI) found that cyclodextrins produce biologically-active proteins that can be used for processing food and treating medical conditions such as diabetes, blood clots and cystic fibrosis.

Rejuvenating inactive proteins is of major interest to the food, drug and chemical industries, which spend millions of dollars annually on the production of proteins. Worldwide sales of pharmaceutical proteins are estimated at $900 million per year. Annual U.S. sales of food enzymes total $49 million for use in meat tenderizing, fruit and vegetable processing, and the production of fats, oils, cheeses, baked goods and corn syrup.

Instead of having to discard inactive proteins, companies that manufacture them now may be able to use the technology to rejuvenate them at a fraction of the cost of producing new proteins. Proteins are expensive. They must be isolated and purified from their biological sources, a process that is complex, wasteful, time-consuming and requires intensive skilled labor.

Another major problem with proteins is their relatively short shelflife. Most proteins become biologically inactive in a few days, and traditional ways of rejuvenating them are not very effective. In their natural state, protein molecules are folded into three-dimensional structures. Functionally inactive proteins have become misfolded or unfolded. The problem for scientists has been to find a way to refold protein molecules back into their natural, three-dimensional states. Previously-patented refolding methods have produced little success.

Michigan's laboratory experiments found that the interaction of proteins with cyclodextrins enhances the refolding of proteins. Cyclodextrins eliminate a common problem encountered with unfolded proteins known as aggregation, which occurs when the amino acids that make up a protein stick to each other in a random fashion and form a blob.

The use of cyclodextrins as a protein-folding aide has several economic advantages over other methods. In addition to producing significantly higher yields of biologically-active proteins, cyclodextrins are inexpensive and commercially available in bulk.

Research Corporation Technologies Inc. (101 N. Wilmot Rd., Suite 600, Tucson, AZ 85711), which applied for and received the patent, is looking to commercialize the new technology on behalf of Central Michigan University and the inventors.

Patent. 5,728,804-Use of cyclodextrins for protein renaturation. Issued May 17, 1998. Patent discusses a method for renaturing a denatured protein. Inventors: Ajit Sharma and Nadarajah Karuppiah. Assigned to Research Corporation Technologies Inc.

Further information. Michael Koerner; phone: [phone]; fax: [phone]; email: [e-mail].