Printer Friendly

Enzymes release caged chemicals.

A new controlled-release system relies on enzymes to unshackle chemicals only when and where they're needed. Scientists at the Netherlands Organization for Applied Scientific Research in Zeist are developing what they're calling bioswitches for a number of applications, such as a germ-killing plastic wrap for meats.

The researchers encapsulated lysozyme-a natural antibiotic--within a cage of chemically linked starch molecules and seeded the complexes onto the wrap's surface. Any bacteria contaminating a piece of meat would view the starch as a snack, explains project manager Hans Boumans, a biochemist. Once the microbe starts feasting on the starch cage, it opens holes and releases the killer lysozymes. "It's like a Trojan horse," says Boumans.

Contact lens cleaners offer another application. Wearers are supposed to soak their dirty lenses for 7 minutes in dilute hydrogen peroxide and then neutralize the chemical with the enzyme catalase. However, impatient consumers often neutralize the solution too soon, cutting short the disinfection step.

The Dutch researchers developed a catalase-releasing bioswitch that can be added to the peroxide at the same time as the lenses are. Boumans' team engineered the bioswitches to release a starch-degrading enzyme--amylase--that slowly breaks apart the cage that contains it. They tweaked the cage design so that it would degrade after only 7 minutes of soaking.

The team is also tailoring edible bioswitches to protect expensive mid unstable flavoring molecules until they contact enzymes on the taste buds, Boumans says. Other complexes would bypass the tongue and carry certain foul-tasting nutrients to the stomach, where enzymes would release the molecules.
COPYRIGHT 2007 Science Service, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2007, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:CHEMISTRY
Publication:Science News
Date:Apr 14, 2007
Words:256
Previous Article:Even outdoors, generators pose risks.
Next Article:New agent to spy clogged arteries.


Related Articles
Cages, cavities and clefts: by building and setting molecular traps, chemists shed light on how one molecule recognizes another.
Identifying cells' chemical personalities.
C60: definitely a beauty, maybe a beast.
Bottled enzymes make complex chemicals.
Single enzymes twist and twitch over time.
Aspirin works on plants, too.
Five firms honored with Presidential Green Chemistry Challenge Award.
Chemistry AU naturel: mimicking nature's clean and efficient ways.
Chemistry and chemical engineering.
Cysteine assistance.

Terms of use | Privacy policy | Copyright © 2019 Farlex, Inc. | Feedback | For webmasters