Enzyme-Polyethylene Glycol Adducts: Modified Enzymes with Unique Properties

Abstract

There are many clinical disorders which, in theory might be treated by the use of appropriate enzymes. However, there are serious problems associated with enzyme therapy. First, inadequate amounts of human enzymes are available; and most foreign enzymes are immunogenic in humans. They can be administered only a few times. Second, the circulating life in the blood may be very short even on the first injection (often a matter of a few minutes). And third, the cost of highly purified enzymes may be too great to allow general use.