Practical Uses Of Enzymes

Practical Uses Of Enzymes

Alcoholic fermentation and other important industrial processes depend on the action of enzymes that are synthesized by the yeasts and bacteria used in the production process. A number of enzymes are used for medical purposes. Some have been useful in treating areas of local inflammation; trypsin is employed in removing foreign matter and dead tissue from wounds and burns. 

HISTORICAL REVIEW

Alcoholic fermentation is undoubtedly the oldest known enzyme reaction. This and similar phenomena were believed to be spontaneous reactions until 1857, when the French chemist Louis Pasteur proved that fermentation occurs only in the presence of living cells (see Spontaneous Generation). Subsequently, however, the German chemist Eduard Buchner discovered (1897) that a cell-free extract of yeast can cause alcoholic fermentation. 

The ancient puzzle was then solved; the yeast cell produces the enzyme, and the enzyme brings about the fermentation. As early as 1783 the Italian biologist Lazzaro Spallanzani had observed that meat could be digested by gastric juices extracted from hawks. This experiment was probably the first in which a vital reaction was performed outside the living organism. 

After Buchner's discovery scientists assumed that fermentations and vital reactions in general were caused by enzymes. Nevertheless, all attempts to isolate and identify their chemical nature were unsuccessful. In 1926, however, the American biochemist James B. Sumner succeeded in isolating and crystallizing urease. Four years later pepsin and trypsin were isolated and crystallized by the American biochemist John H. Northrop. Enzymes were found to be proteins, and Northrop proved that the protein was actually the enzyme and not simply a carrier for another compound.

Research in enzyme chemistry in recent years has shed new light on some of the most basic functions of life. Ribonuclease, a simple three-dimensional enzyme discovered in 1938 by the American bacteriologist René Dubos and isolated in 1946 by the American chemist Moses Kunitz, was synthesized by American researchers in 1969. The synthesis involves hooking together 124 molecules in a very specific sequence to form the macromolecule. 

Such syntheses led to the probability of identifying those areas of the molecule that carry out its chemical functions, and opened up the possibility of creating specialized enzymes with properties not possessed by the natural substances. This potential has been greatly expanded in recent years by genetic engineering techniques that have made it possible to produce some enzymes in great quantity (see Biochemistry).

The medical uses of enzymes are illustrated by research into L-asparaginase, which is thought to be a potent weapon for treatment of leukemia; into dextrinases, which may prevent tooth decay; and into the malfunctions of enzymes that may be linked to such diseases as phenylketonuria, diabetes, and anemia and other blood disorders.