Enzymes
Prolonged heat over 48°C (118°F) kills 100% of the enzymes, leaving the bulk of nutrients with no helpers (enzymes) to take them where they should go. Sustained body temperatures of over 40°C (104°F) are usually fatal because enzymes throughout the body undergo denaturation and become permanently nonfunctional.
Enzymes are also very sensitive to their environment. Too much acid or alkaline will affect their activity, as will temperature, concentrations of a necessary substrate, coenzymes, and inhibitors. In addition, enzymes are very specific. Each one promotes one type of chemical reaction -- and one type only.
Usually, it is the glands and major organs, including the brain, that suffer the most. The pancreas will also swell to meet the great demand for its secretions. Over time, it has been shown that the brains of animals actually shrink from an all-cooked, overly-refined diet. It seems unlikely that humans would fare any different.
Ninety percent or more of all the carbohydrates eaten are used to form ATP, or cell energy. This is why limiting carbohydrates may help you lose weight, but it is devastating on the cells in the long run as they try to meet the demands of the body without adequate refueling.
Enzymes are necessary to properly digest and absorb all nutrients in order to give the body what it needs to function. No matter how many nutrients are eaten, the nourishment desired is futile without enzymes to digest and help transport them.
Enzymes are proteins (long chains of amino acids that differ in order and number) made by living cells to promote specific metabolic reactions.
Cofactors are ions or molecules (a mineral or an electrolyte) that must attach to the active site before substrate binding can occur and enyzmes act as cofactors.
Haloenzyme is an enzyme that is activated by an appropriate cofactor.
Apoenzyme is an inactive enzyme without its cofactor.
Coenzymes function as cofactors and consist of large organic molecules, often formed by the body from many vitamins in order to function as essential coenzymes. A coenzyme is a necessary helper for enzymes. Since the body cannot make them, they must be obtained from food. In humans, coezymes are usually the B vitamins that help enzymes release energy from carbohydrates, fat, and protein. Vitamin B6 assists those enzymes that metabolize amino acids. Folate and vitamin B12 work with enzymes in helping cells to multiply. Fat-soluble vitamins are not usually considered to be coenzymes; but, because they are involved in so many bodily functions, their presence is essential. Therefore, they may be considered as “indirect” coenzymes. Unlike enzymes, coenzymes are not proteins, but they do require constant replacement since their action takes place during consumption of food.
Metalloenzyme is an enzyme that contains one or more minerals as part of its structure.
Isozymes are enzymes that differ in structure but catalyze the same reaction. Different tissues often contain different isozymes. When tissue damage occurs, isozymes leak out of the injured cells into the tissue fluid and the blood. Thus, the identification of a particular isozyme can provide direct evidence of damage to a specific tissue. For example, the enzyme lactate dehydrogenase (LDH) catalyzes a reaction that produces lactic acid during periods of intense muscular activity. Cardiac muscle and skeletal muscle have different isozymes of LDH. When a patient reports experiencing severe chest pain, an LDH assay is often performed. If the pain resulted from a heart attack, cardiac LDH levels will be elevated.
Six major classes of enzymes
- Ligase requires ATP and string nucleotides together in nucleic acids and simple sugars in polysaccharides.
- Lyase breaks bonds between carbon atoms or between carbon and nitrogen. For example, deaminase removes amino group from amino acid.
- Hydrolase breaks large molecules into simpler molecules with the addition of a water molecule. For example, proteases split proteins into amino acids; amylase splits carbohydrates into simple sugars; and lipase breaks apart triglycerides.
- Transferase removes a part of one molecule and attaches it to another. For example, transaminase transfers an amino group from an amino acid.
- Isomerase rearranges the atoms in a molecule without changing the chemical formula. It is important in preparing some carbohydrates for enzymatic processing.
- Oxido-reductase removes hydrogen or electrons from one molecule and gives them to another. They are involved in mitochondrial energy production.
- Kinase attaches a phosphate group with a high-energy bond. It is essential for ATP production and the activation of some enzymes.
Three major types of enzymes
- Food enzymes are found in raw foods. All food, whether animal or plant, contains enzymes.
- Digestive enzymes are secreted by the body to digest the food eaten. There are three categories of digestive enzymes:
- Amylases (found in saliva, the pancreas, and intestinal juices) break down carbohydrates;
- Proteases (found in the stomach, pancreatic, and intestinal juices) help digest protein;
- Lipases (found in the stomach and pancreatic juices, and in food fats) aid in fat digestion.
- Metabolic enzymes run all the body organs and systems by performing various chemical reactions within the body cells. Without them, life would cease to exist. Two important metabolic enzymes are SOD (superoxide dismutase, which is an antioxidant and Catalase, which breaks down hydrogen peroxide, a metabolic waste product, liberating the oxygen for use in the body.
Digestive enzymes and their function
- Amylase I and II are secreted, first by the salivary glands, and then by the pancreas. They function best in a pH of 6.7-7.5, breaking bonds between carbohydrate molecules to produce disaccharides and trisaccharides. Amylase I is activated by chewing and begins the digestive process by converting starch (amylose) to maltose. Amylase II, produced by the pancreas, is only slightly different chemically and continues the process started by the salivary amylase.
- Pepsin is secreted as proenzyme pepsinogen by the chief cells of the stomach and activated by hydrogen in the stomach acid, also producing hydrochloric acid at the same time. It functions best in a pH of 1.5-2.0 in order to break bonds between amino acids in proteins, producing short-chain polypeptides and destroying any pathogens that enter with the food.
- Trypsin is secreted from the pancreas as proenzyme trypsinogen. It functions best in a pH of 7-8. Trypsin acts on proteins and polypeptides to produce short-chain peptides. It also activates other pancreatic proteinases.
- Chymotrypsin is secreted by the pancreas as proenzyme chymotrypsinogen. It functions best in a pH of 7-8. Chymotrypsin acts on proteins and polypeptides to produce short-chain peptides.
- Carboxypeptidase is secreted by the pancreas as proenzyme procarboxypeptidase. It functions best in a pH of 7-8. Carboxypeptidase acts on proteins and polypeptides to produce short-chain peptides and amino acids.
- Elastase is secreted by the pancreas as proenzyme proelastase. It functions best in a pH of 7-8. Elastase targets elastin to produce short-chain peptides.
- Lipase is secreted by the pancreas -- but only if bile salts are present. It functions best in a pH of 7-8. Lipase targets triglycerides to produce fatty acids and monoglycerides. Lipase also seems to be activated by the presence of Vitamin C, glutathione, and cysteine.
- Nuclease is secreted by the pancreas. It functions best in a pH of 7-8. Nuclease targets nucleic acids RNA and DNA to produce nitrogen bases and simple sugars.
- Enterokinase is secreted by the mucosal cells of the small intestine and reaches the lumen through disintegration of shed epithelial cells. It functions best in a pH of 7-8. Enterokinase targets trypsinogen, a proenzyme, to produce trypsin.
- Maltase, sucrase, and lactase are secreted by the mucosal cells of the small intestine and found in the membrane surface of microvilli. They function best in a pH of 7-8. They respectively target the sugars maltose, sucrose, and lactose to produce monosaccharides.
- Peptidase is secreted by the mucosal cells of the small intestine and found in membrane surfaces of the microvilli. It functions best in a pH of 7-8. Peptidase targets dipeptides and tripeptides to produce amino acids.
Other common enzymes
- Bromelain is found in pineapple. It is a digestive enzyme that breaks down protein. It also has anti-inflammatory properties and has proven effective in treating rheumatoid arthritis and osteoporosis. It also improved mobility while decreasing pain and joint swelling. Bromelain also breaks down the fat/cholesterol casings that surround a clot and can “clean up” arterial plaque. By eating raw pineapple, cardiac function can improve, as well as symptoms of CHF (congestive heart failure). However, too many people take aspirin for this purpose, which only prevents the clumping of clots in the blood. It does not prevent the accumulation of the fats that cause atherosclerosis.
Note that the enzyme is found only in fresh pineapple and is destroyed in canning or freezing. - Papain is found in papaya. It is often used with bromelain. Both are used as meat-tenderizers and to help with protein digestion and in controlling acidic conditions of the stomach.
- Rennin is found only in the stomachs of infants. It is a milk-clotting enzyme. Rennin readies the milk for the action of pepsin in breaking down the proteins and for lipase to break down the fats.
Supplemental enzymes
- Pancreatin is usually obtained from an animal source. It is unique because it possesses proteolytic, lipolytic, and amylolytic properties: proteolytic enzymes (chymotrypsins, trypsins, pancreato- and carboxypeptidases), amylases, lipases, phospholipases, as well as nucleic acids (RNA and DNA). It is most active in a pH of 6.5 to 9.0. It is mainly used when there is pancreatic insufficiency, inadequate secretions of exocrine pancreas, disturbed digestion after gastrectomy, and in children with cystic fibrosis.
- Trypsin also comes from an animal source, usually ox pancreas. It has endoproteolytic properties and splits peptides, amides, and esters. It is most active in a pH of 7.0 to 9.0 and often used in the debridement of necrotising wounds, ulcerations, abscesses, empyemas, hematomas, fistulas, and decubitus ulcers. It can be used internally or externally to accelerate healing in injuries, inflammations, phlogistic edemas, and traumatic changes as well as an auxilary agent in meningitis therapy.
- Chymotrypsin is another one from an animal source, usually ox and pork pancreas. It has endoproteolytic activities, splitting peptides, amides, esters, and other amino acid-containing compounds. It is most active in a pH of 8.0 and used in the debridement and treatment of abscesses and ulcerations, as well as in the liquefaction of mucous secretions, in ophthalmic cataract surgeries and therapy of eyeball hematomas and ophthalmorrhagias, and in before and after tooth extractions, as well as other forms of dentistry. Chymotrysin has been used after episiotomy surgeries, as an anthelmintic agent against enterozoic worms, in early recognition of tumor cells, and in histologic gastroenterologic diagnostics.
- Papain is obtained from papaya latex of Carica papaya. It splits peptides, amides, and esters and is most active in a pH of 2.5 to 7.0. It is used in ophthalmology to prevent cornea scar malformation, intoxications caused by stings of jellyfish and insects, malabsorption syndromes like gluten intolerance, treating phlogistic edemas, inflammatory processes, and in accelerating wound healing.
- Bromelain is obtained from pineapple stems of Ananas comosus and is a mixture of bromelain A and B, two sulfur-containing proteinases that split peptides, amides, and glycine esters. It is most active in a pH of 3.0 to 8.0 and used as an adjuvant in treatment of swelling and inflammations caused by injury and surgery, as well as for painful menstrual hemorrhages, such boxing injuries as facial swellings and hematomas, acute sinusitis, and in thromboembolism of central retinal vessels.
- Amylase is obtained from a fungal source, usually from Aspergillus oryzae. It requires calcium ions for its activity on starch, glycogen, and related poly- and oligosaccharides. It is most active at a pH of 6.5 and used with other enzymes as a digestant.
- Lipase is obtained from a fungal source, usually from Aspergillus oryzae. It depends on calcium ions for its activity of splitting emulsified neutral fats into fatty acids and glycerol. It is most active in a pH of 5.0 to 7.5 and used to increase pancreatic and lipolytic activities in pancreatin-containing remedies. It reduces fat levels in stools when given in combined preparations with pancreatin. It also intensifies syngergistically biocatalytic activity of lipoprotein-lipase in the blood and the migration of agranulocytes.
- Lactase is obtained from a fungal source Aspergillus niger and a yeast source Saccharomyces lactis. A. niger is most active in a pH of 4.0 to 5.0, while S. lactis prefers 6.0 to 8.5. Lactase is used to treat lactose insufficiency and as a digestive aide.
- Cellulase is obtained from a fungal source, usually Aspergillus niger. It breaks down cellulose and cereal glucans and used as a digestive aid. (Cichoke)
Bibliography
- Cichoke, Anthony J. Enzymes and Enzyme Therapy. 2000.
- Howell, Edward. Enzyme Nutrition. 1985.
- McCance, Kathryn L. and Sue E. Huether. Pathophysiology: The Biologic Basis for Disease in Adults and Children. 1990.
- Martini, Frederic. Fundamentals of Anatomy and Physiology. 1992.
