Enzymes are proteins produced by all living organisms, and like all proteins, they consist of amino acids. What makes these proteins different from other proteins is how they behave in the body. By definition, enzymes are catalysts that make many essential biochemical reactions ‘happen’ and are not used up or chemically altered in the process. As a catalyst, they help a chemical reaction take place quickly and efficiently.

Here is a list of enzymes and their function in the human body
I will update the information as I come across more information:

Aldose reductase is an enzyme normally present in the eye and elsewhere in the body. It helps change glucose (sugar - glucose) into a sugar alcohol called sorbitol. Too much sorbitol trapped in eye and nerve cells can damage these cells, leading to retinopathy and neuropathy. Substances that prevent or slow the action of aldose reductase are being studied as a way to prevent or delay these complications of diabetes. Aldose reductase is the first enzyme in the sorbitol pathway. This pathway is responsible for the conversion of glucose to sorbitol, and of galactose to galactitol. Under conditions of hyperglycemia, sorbitol accumulation occurs. Aldose reductase inhibitors prevent the accumulation of intracellular sorbitol. One such substance is rutin.
Aminopeptidases attack the amino terminal (N-terminal) of peptides producing amino acids.
Amylase to digest carbohydrates. Amylase is secreted by the pancreas and small amounts are also made in the salivary glands. Amylase is the enzyme that hydrolyses starch to maltose (a glucose-glucose disaccharide), as well as the trisaccharide maltotriose and small branchpoints fragments called limit dextrins.
Bromelain is found in pineapples. Bromelain is also sold as a supplement.
Carbonic anhydrase relies on zinc for proper functioning. The carbonic anhydrase enzymes in red blood cells help the body expel carbon dioxide, with the demand rising substantially during exercise.
Carboxypeptidase removes, one by one, the amino acids at the C-terminal of peptides.
Catalase is a powerful antioxidant.
Cellulase for fruit and vegetable digestion
Chymotrypsin
Cyclooxygenase (COX-1)
Disaccharidases convert disaccharides into their monosaccharide subunits.
Elastase cuts peptide bonds next to small, uncharged side chains such as those of alanine and serine.
Ficin enzyme from figs
Glutathione
Lactase for milk sugar digestion
Lactate Dehydrogenase - The enzyme LDH is in many body tissues, especially the heart, liver, kidney, skeletal muscle, brain, blood cells, and lungs.
LIpase for fat digestion. The drug orlistat (Xenical) is a pancreatic lipase inhibitor that interferes with digestion of triglyceride and thereby reduces absorption of dietary fat. The health concerns regarding the use of orlistat and blocking of fat absorption are yet to be fully understood.
Lysozyme - Lysozyme is an enzyme found in a number of secretions, such as tears. This enzyme is present in in egg white. Lysozyme is a natural "antibiotic" protein found in tears and certain secretions. Although proteins are usually tasteless, there are some, such as the enzyme lysozyme, which elicit a sweet taste on the human palate. Most of the sweet-tasting proteins have a high isoelectric point, but no homology has been observed in amino acid sequences and tertiary structures.
Maltase hydrolyzes maltose into glucose.
Lipoxygenase -- 5-lipoxygenase
Nattokinase is a fibrinolytic enzyme considered to be a promising agent for thrombosis therapy.
Nitric oxide synthase -- makes nitric oxide from the amino acid arginine.
Nucleases hydrolyze ingested nucleic acids (RNA and DNA) into their component nucleotides.
Pancreatin enzyme is found in Wobenzym supplement and also in other formulations.
Papain -- Papaya enzymes
Pepsin is secreted in the stomach. Digestion of proteins is initiated by pepsin in the stomach, but the bulk of protein digestion is due to the pancreatic proteases secreted in the small intestine..
Serrapeptase enzyme. You can purchase Serrapeptase enzyme online.
Sirtuin proteins
Superoxide Dismutase is a powerful antioxidant enzyme.
Sucrase hydrolyzes sucrose (common table sugar) into glucose and fructose.
Telomerase enzyme - Lifestyle changes including a better diet and more exercise can raise the body's levels of telomerase enzyme which is closely involved in controlling the aging process. A small study involved 30 men with low-risk prostate cancer who underwent three months of lifestyle changes. They had blood levels of the enzyme telomerase 30 percent higher after these three months than when they began. Telomerase fixes and lengthens parts of chromosomes known as telomeres that control longevity and are also important for maintenance of immune-system cells. The lifestyle changes included a diet rich in fruits, vegetables, whole grains, legumes and soy products, moderate exercise such as walking for half an hour a day, and an hour of daily stress management methods such as meditation.
Trypsin
Xanthine oxidase

Antioxidant Enzyme
Catalase
Glutathione
Superoxide dismutase

Blood clot dissolving enzymes
Nattokinase from natto

Cardiac Enzymes - Heart Enzymes

Natural Digestive enzymes - Supplements
These include proteases, amylases and lipases that are involved in the breakdown of ingested proteins, carbohydrates and lipids (fats) respectively. Proper breakdown of these ingested foods is necessary to allow proper absorption of the nutrients to occur. Digestive enzymes and digestive enzyme supplements -- Natural digestive enzymes
     Digestive enzymes are produced in the pancreas and salivary glands and help to break down the protein, carbohydrate, and fat components of food for use by the body. For more details and a thorough discussion, see Digestive Enzymes.

Food enzymes
Bromelain is found in pineapples
Ficin from figs
Nattokinase from natto
Papain -- Papaya enzymes

Liver enzymes -- High liver enzymes cause
Elevated liver enzymes high liver enzymes
     Cause of elevated liver enzymes
Lactate Dehydrogenase - The enzyme LDH is in many body tissues, especially the heart, liver, kidney, skeletal muscle, brain, blood cells, and lungs. LDH catalyzes the interconversion of pyruvate and lactate. Exercising muscles convert (and red blood cells metabolize) glucose to lactate. Lactate is released into the blood and is eventually taken up by the liver. The liver converts lactate back to glucose and releases glucose into the blood. This glucose is then taken up by resting muscles, red blood cells, and other tissues.

Papaya Enzymes
Papain

Proteolytic enzymes
Nattokinase and Serrapeptase

I am a chiropractor and often see articles suggesting that proteolytic enzymes can effectively lower cholesterol. In my practice I recommend their use as an anti-inflammatory in athletic injuries and have seen  literature that suggests that they may be of benefit in stablizing cardiac artery inflammation (this reducing the risk of MI). Other than testimonials, however, I've not seen research that supports the use of proteolytic enzymes to reduce serum cholesterol. Can you offer any insight?
   We have not come across research regarding proteolytic enzymes and cholesterol.

I'm very interested in what I'm reading about the enzyme Seaprose-S (I'm currently taking serrapeptase) -- however it doesn't seem to be available online anyplace. Is this supplement actually available to the public in USA (I know it originates in Japan)?
   Seaprose S is a protease made by Amano Enzyme Inc.. Seaprose S is obtained from fermentation of the microorganism Aspergillus melleus.

Pancreatic Enzymes

Proprietary enzyme formulas
Wobenzym
     Pancreatin 300 mg
     Papain 180mg
     Bromelain 135 mg
     Trypsin - 72mg
     Chymotrypsin 3mg
     Rutosid 150 mg

Systemic enzymes
I am not exactly sure what people mean by the term systemic enzyme or whether there is an acceptable definition of what systemic enzymes are. Some people define systemic enzymes as those enzymes not just for digestion, but taht work throughout the body in every system and organ. Some websites included the following as systemic enzymes: papain, bromelain, nattokinase, pancreatin and nattokinase. Another website claims, "Systemic Enzymes are designed to pass through your stomach to reach your intestine. The coating of Systemic Enzymes allows the enzymes to reach your intestine where they can function properly. Once there, clinical studies show that systemic enzymes benefit the body by addressing inflammation, speeding up the healing process of damaged tissue, reducing pain, and addressing cardiovascular issues."
   At this time I am personally not sure how one exactly defines which enzyme are considered within the category of systemic enzymes, and whether it is necessary to use such a term.

Enzyme Replacement Therapy information

Enzyme replacement therapy for lysosomal storage diseases did not become a reality until the early 1990s when its safety and effectiveness were demonstrated in type 1 Gaucher disease. Today, ERT is a reality for Gaucher disease, Fabry disease and mucopolysaccharidosis type I (MPS I), and clinical trials with recombinant human enzymes are ongoing in Pompe disease.

Emails
Q. There is a lot of controversy between doctors on whether the stomach absorbs enzymes intact. They are catalyst proteins. I can see the rightness of both sides of the argument. There are clinical trials that prove something of absorbed enzymes combat inflammation and break down cysts. There is also clinical evidence that any whole protein that gets into the body that wasn't manufactured in that body, is attacked as an invader and broken down into it's amino constituents. This is proven by the fact that transplanted organs require immune inhibition drugs to keep the transplanted organ from being destroyed because antibodies view the proteins as invaders. It is also true that certain kinds of protein , such as gelatin, are digested and absorbed, and put back together as your body's kind of collagen and obviously used to improve nails, hair, skin and joints. In the face of all this evidence, I am led to believe, that indeed, all proteins including enzymes are broken down into their amino constituents, in the digestive tract. But, the amino constituents must be somehow marked for what they were part of, because they seem to be put back together, in the blood or body, as an immune acceptable form of what they once were, since they directly benefit the body for what they once were. So, it is my observation that both sides of the controversy on whether enzymes are absorbed is right. It's just that both sides are incomplete in what they are saying, because neither side has considered that amino constituents may be marked for what they once were part of and reassembled into that particular body's version of what they once were in the way of whole proteins.
   A. You bring up an excellent question that is hotly debated. When I was in medical school, we were told that everything we ate in our foods, including proteins, were broken down into amino acids. Hence, it would appear that there is no point in taking certain protein enzymes of any sort since they would be broken down. However, with time, I have gradually shifted my opinion that perhaps some larger molecules are absorbed intact into the bloodstream and are not necessarily broken down into the smallest particles. As to whether there is an intelligence that reassembles enzymes back together again from their individual constituents is beyond my knowledge since I focus mostly on clinical aspects of medicine rather than the more detailed biochemical or physiological aspects of metabolism.

Q. I recently came across a press release that I was hoping you could comment on since I respect your opinon. This is it: "Ellen Cutler has a message making its way to health conscious Britons. Her newest book MicroMiracles: Discover the Healing Power of Enzymes (Rodale, 2006) has been released in the UK, with the title Enzymes for Health and Healing. Cutler is a tireless advocate of enzyme supplementation, and is regarded as one of the foremost authorities on the subject of this millennium. She was a key player in the development of the WellZymes line of digestive and systemic enzymes from Enzymes, Inc. In fact, the formulations found in the WellZymes product line are those detailed in Enzymes for Health and Healing. “Enzyme supplements from the WellZymes product line are among the most effective products on the retail market today,” explains Cutler. “They are 100% vegetarian, are stable over a wide range of pH levels, and contain only the finest enzymes and herbal extracts.” Enzymes, Inc. has been formulating enzyme based nutritional supplements used in the health care industry for over two decades. The WellZymes product line was created to provide a professional quality enzyme supplement for the health conscious consumer. While somewhat of a nascent area of healthcare, as more and more doctors and patients discover the efficacy of digestive and systemic enzyme supplementation, it is rapidly becoming more mainstream. “Poor digestion can cause a array of other kinds of problems,” said Cutler, “such as: not being able to focus, cholesterol problems, other kinds of cardiovascular situations, rashes, eczema, hair falling out, nails breaking, pain and inflammation, and mood swings.” Products from the WellZymes product line were specifically designed to assist in the treatment of many different health conditions."
   A. The whole topic of enzyme supplementation is quite confusing and difficult to give any confident answers on. Without doing actual stomach acid and intestinal acid analysis or other tests, it is difficult to say whether someone is short on digestive enzymes, and if so, which. Therefore, to make a statement such as "Enzyme supplements from the WellZymes product line are among the most effective products on the retail market today," and implying that digestive enzyme supplementation will cure a number of diseases... is premature. There may be some people who may benefit from taking a digestive enzyme supplement, and there may be many more people who take these enzyme supplements that don't actually get anything for it except a hole in their pocket. Many people with various health conditions sometimes attribute their problems to poor digestion whereas the problem could be due to something else.

Q. I just happened to come across your enzyme site in my search for information about some certain enzymes, and while I did find your site to be incredibly informative, I also happened to see a question posed at the bottom of the page, Digestive Enzyme emails: Q. I wonder if you can help. I am looking for a supplement that has trypsin, chymotrypsin and carboxypeptidase in it and am not having much success in locating such a supplement. A. We don't know of such a product at this time, but if we do we will mention it in the newsletter. I am not a maker of this, nor have i even tried it, but i wanted to forward this website to you and see if you have heard of and have any information about this particular website and enzyme product. http://home.bluegrass.net/~jclark/omnizyme.htm If you could provide any information on whether or not this would be a good supplement to assist with food breakdown and as an anti-inflammatory, I would greatly appreciate it.
   A. Their website says, Omnizyme Forte ( with 125 mg Trypsin and 45 mg Chymotrypsin ) 200 tablets. Simply the BEST Proteolytic Enzymes available in the world today, bar none! Digestive enzymes also called pancreatic enzymes include three classes of enzymes... Proteolytic enzymes needed to digest protein, Lipases needed to digest fat and Amylases needed to digest carbohydrates.
   Comments: We become suspicious when a website claims that their product is the best in the world. We don't know this company and hence do not know the quality of their product.

Q. I've read somewhere that pineapple enzymes helps you lose weight and belly fat? I'm 5'2 weight 145 pounds female age 47. I'm asthmatic due to a partial left lung removable since age 4. I am borderline high blood pressure working in a very stressful job. The only medication I take is through inhalations for my asthma Advair 500 and Albuterol. My stomach is a problem which I have a hard time losing weight there due to a lower back injury and a removal of my gallbladder. Despite, I take a supplement of mega-zyme extra-strength before meals. I still get bloated and have gas. I've ordered CoQ10, and Diet Rx. Which supplements do you recommend.
   A. We have not seen good research regarding the use of pineapple enzymes and weight loss. We can't make any specific recommendations, but we suggest using each supplement by itself for a week before trying another one. This way you can tell the influence of each one on your body rather than being confused when taking multiple supplements and not knowing which one is doing what.

Is is a good idea to order enzyme products before the weather gets into the 90s here in Texas? I know that enzymes are not supposed to get hot. Also, if just purchasing an enzyme off the shelf of a local store, how do you know if the product is viable? Is there a simple test procedure I could do at home?
    Much depends on the quality of the enzyme product, the type of enzyme, and how long ago it was manufactured. It is best not to expose enzyme products to excessive heat, but I doubt there would be much harm during the shipping process of a few days. It is a good idea to store them in the fridge. There is no reliable way to tell at home if the enzyme is still active, the product would have to be sent to a lab for analysis to determine if the enzymes are still active.

I'm having a hard time finding information related to enzyme supplementation and the possible effects on transplanted organs. I don't understand the biochemical mechanism of rejection, so I'm cautious recommending proteolytic enzymes for my friend who had a kidney transplant. She does experience significant pain from inflammation, and is under Dr's orders to refrain from NSAIDs. Any info you may have on the topic would be greatly appreciated, even other possible natural source of anti-inflammatory substances that would be otherwise innocuous (i.e. fish oil?).
    The topic of enzyme supplementation or the use of various supplements to those patients who have had organ transplantation is very complicated and there are no simple answers and little human research to give us clues on the safety of such natural products in these situations.

Suppliers
There are many raw material suppliers that provide enzymes. We received an email from one of them.
     BioMedico Labs has been supplying enzymes to the dietary supplement industry since the year 2005. We offer a wide variety derived from plants, fungi, and bacteria including bromelain, protease, amylase, lactase, and lipase that can be formulated into your dietary supplement product. With a large inventory at all times and a comprehensive portfolio of enzymes, BioMedico Labs is the most sensible choice to become your supplier of enzyme preparations. BioMedico Labs will go the extra mile to offer its clients the highest quality products at a very competitive price with personalized service. We are well-acquainted with enzyme ingredients currently being marketed in dietary supplements. Our technical sales representatives are available to work with you to meet your enzyme needs. If you have specifications for a dietary supplement containing enzymes, or if you need help with formulating an enzyme-based dietary supplement, feel free to contact us for a quote or for general information. BioMedico Labs offers custom package sizes and low minimum order requirements to allow our customers maximum flexibility in their ordering.