The enzyme for a low-cholesterol diet.The enzyme for a low-cholesterol diet By converting one double bond into a single bond, the enzyme cholesterol reductase reductase /re·duc·tase/ (-tas) a term used in the names of some of the oxidoreductases, usually specifically those catalyzing reactions important solely for reduction of a metabolite. changes cholesterol into coprostanol. And that change can be important, because unlike cholesterol, coprostanol is not absorbed by the human body. Researchers at Iowa State University Academics ISU is best known for its degree programs in science, engineering, and agriculture. ISU is also home of the world's first electronic digital computing device, the Atanasoff–Berry Computer. in Ames are attempting to isolate and harness cholesterol reductase to lower the cholesterol content of milk, eggs, meats and butter. Their work initially focused on Eubacteria eubacteria Term formerly used to describe and differentiate the true bacteria from the archaebacteria. Today, the true bacteria form the domain Bacteria, and the archaebacteria (also an obsolete term) form the domain Archaea. , microbes that contain cholesterol reductase and inhabit the large intestine large intestine End section of the intestine. It is about 5 ft (1.5 m) long, is wider than the small intestine, and has a smooth inner wall. In the first half, enzymes from the small intestine complete digestion, and bacteria produce many B vitamins and vitamin K. . They added Eubacteria to high-cholesterol foods and incubated them at the microbes' normal temperature -- about 98.6[deg.]F. While this reduced the foods' cholesterol content 80 percent, it also caused the foods to spoil--an effect due at least in part to the temperature. That's one reason the Iowa researchers want to extract the enzyme and add it to foods directly. Their most recent work suggests the microbes' conversion of cholesterol involves a three-step process--and possibly the activity of three genes. This suggests that identifying the operant operant /op·er·ant/ (op´er-ant) in psychology, any response that is not elicited by specific external stimuli but that recurs at a given rate in a particular set of circumstances. op·er·ant adj. genes and splicing splicing /splic·ing/ (spli´sing) 1. the attachment of individual DNA molecules to each other, as in the production of chimeric genes. 2. RNA s. them into other microbes--so that the enzyme could be commercially produced -- might prove difficult, says Donald Beitz, a nutritional biochemist leading the work. So now he's focusing on plants. Though cholesterol is made only by animals, Beitz and his co-workers recently found the enzyme that converts it to coprostanol in the leaves of cucumbers, corn, soybeans and peas. Moreover, their preliminary data suggest coprostanol synthesis by the plant's enzyme, may be a one-step process--involving one gene--and one gene might prove easier to splice into E. coli E. coli: see Escherichia coli. E. coli in full Escherichia coli Species of bacterium that inhabits the stomach and intestines. E. coli can be transmitted by water, milk, food, or flies and other insects. or other bacteria that might be used for commercially mass-producing the enzyme. Beitz envisions the day when the shells of eggs coming down a conveyor belt might be drilled open, injected with the enzyme (and perhaps with a pretreating enzyme) and resealed. By the time an egg is eaten, he says, it cholesterol might be all but gone. |
|
||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion