Proteolytic enzymes are produced produced throughout the body in various tissues and cells. All proteolytic enzymes break apart proteins. The biologic functions of proteolytic enzymes vary depending on the type of protein they break apart and the location in the body where this takes place.
Protease
According to "Biochemistry: A Case-Oriented Approach," proteolytic enzymes, called proteases, are themselves proteins. All proteins are ultimately derived from genes within DNA. Genes, located in the nucleus of every cell, contain the blueprint for synthesis of proteins, including the estimated 500 different types of proteases.
Digestive Proteases
Dietary proteins must be broken down in order to be absorbed into the body. The majority of protein digestion occurs in the small intestine. According to "Advanced Nutrition and Human Metabolism," proteases, such as trypsin and chymotrypsin, are produced in the pancreas and exported to the lumen of the small intestine where they break down dietary protein. Digestive proteases are also produced in the stomach and the cells of the small intestine. A combination of different proteases is necessary to fully digest dietary protein.
Intracellular Proteases
All cells produce proteases. Many of these proteases remain inside the cell cytoplasm; others are associated with the cell membrane or other cell organelles. According to "Biochemistry: A Case-Oriented Approach," intracellular proteases are important for achieving an appropriate balance of regulatory proteins for maintenance of cell homeostasis.
Lysosomal Proteases
According to "Advanced Nutrition and Human Metabolism," the lysosome is a cell organelle important for the disposal of unneeded cellular components. Several types of proteases are found in the lysosome. Lysosomal proteases are especially important in cells of the immune system, such as white blood cells.
Circulatory Proteases
Proteases are also found circulating in the blood. According to "Advanced Nutrition and Human Metabolism," these proteases are produced by organs such as the liver and kidney and then exported to the blood. In the blood, circulatory proteases are important for regulating processes such as blood coagulation and blood pressure.
References
- "Advanced Nutrition and Human Metabolism (fifth edition)"; S.S. Gropper, J.L. Smith, J.L. Groff; 2009
- "Biochemistry: A Case-Oriented Approach (sixth edition)"; R. Montgomery, T.W. Conway, A.A. Spector, D. Chappell; 1996
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