Selenocysteine is the analog of cysteine having the same structure as that of cysteine. But here sulphur atom is replaced by selenium. The Health Store Selenocysteine is the 21st amino acid found in the ribosome mediated protein synthesis. It is present in several enzymes (for example glutathione peroxidases, tetraiodothyronine 5′ deiodinases, thioredoxin reductases, formate dehydrogenases, glycine reductases, and some hydrogenases). Selenocysteine has a structure similar to that of cysteine, but with an atom of selenium taking the place of the usual sulfur, forming a selenol group which is deprotonated at physiological pH. Proteins that contain one or more selenocysteine residues are called selenoproteins. There is no single free pool of selenocysteine amino acid that exists within cells to be used
Selenocysteine is the protein, or food form, of the antioxidant selenium, and it is used in almost every cell process in the body. It is one of the only amino acids that is not directly coded into the genetic code, and no free pool of selenocysteine exists within cells to be used. This means that it is an essential amino acid and must be absorbed by cells and obtained through foods to maintain proper levels in the body. The body uses the selenocysteine amino acid to produce selenium. It is believed that this may protect against mercury toxicity, and people with low levels of selenium in their body may be more prone to poor liver function, low muscle mass, premature aging, and even heart disease.
Selenocysteine is created after the digestive system breaks proteins from the diet into its individual amino acids. Selenocysteine is a genetically coded amino acid, serving as a stop codon. Stop codons signal amino-acid chains, which will become proteins, to stop growing, releasing the protein to perform its intended function in the body. Selenoproteins are formed when the amino acid selenocysteine — often called the 21st amino acid — combines with selenium from the diet in a very specific spot in the amino-acid chain.
Functions and benefits Selenocysteine
The important functions of selenocysteine in proteins are its anti –oxidant activity. This is due to its lower pKa and higher reduction potential.
It is also used in the preparation of variety of vitamins and lots of other supplements.
It is also fortified with livestock feeds.
Our body utilizes selenocysteine to form selenium, which is believe to play important role in preventing mercury toxicity as well as enhance liver functions.
Selenocysteine is not directly incorporated into other proteins. It provides its function on its own. For this reason it is highly reactive and not used in the same way as the body uses other amino acids.
In some cases a marked decrease in catalytic activity of an enzyme is observed when a selenocysteine residue is replaced with cysteine. This substitution caused complete loss of glycine reductase selenoprotein A activity.
Selenocysteine is the 21st naturally occuring amino acid, and is coded for by the RNA codon UGA, which is normally a “stop” signal, but is modified in some organisms to create selenocysteine by a subsequent RNA loop, which is interpreted by a group of genes called the sel group, which are activated by the loop in the mRNA and produce molecule of tRNA for selenocysteine.
People deficient with selenium have lean body mass, prone to premature aging.
Weaken the immune system, making the body more susceptible to illness, as well as lead to heart disease or hypothyroidism.
Unlike true amino acids, carnitine is not used for protein synthesis or as a neurotransmitter. Its main function in the body is to help transport long-chain fatty acids, which are burned within the cells, mainly in the mitochondria, to provide energy. This is a major source of energy for the muscles. Carnitine thus increases the use of fat as an energy source. This prevents fatty buildup, especially in the heart, liver, and skeletal muscles. Carnitine may be useful in treating chronic fatigue syndrome (CFS), because a disturbance in the function of the mitochondria (the site of energy production within the cells) may be a factor in fatigue. Studies have shown decreased carnitine levels in many people with CFS.
Carnitine can be manufactured by the body if sufficient amounts of iron, vitamin B1 (thiamine), vitamin B6 (pyridoxine), and the amino acids lysine and methionine are available. The synthesis of carnitine also depends on the presence of adequate levels of vitamin C. Inadequate intake of any of these nutrients can result in a carnitine deficiency. Carnitine can also be obtained from food, primarily meats and other foods of animal origin.
Function and Benefits of Carnitine
Carnitine is available as D-carnitine, L-carnitine, DL-carnitine as well as acetyl-L-carnitine, but L-carnitine is the most popular type.
L-Carnitine is synthesized from the essential amino acids lysine and methionine, but enough vitamin B1 (thiamine) and vitamin B6 (pyridoxine) must be available
Carnitine has also been shown to improve the antioxidant effect of vitamin C and vitamin E
Carnitine can be manufactured by the body if iron, vitamin B1 (thiamine), vitamin B6 (pyridoxine), and the amino acids lysine and methionine are available
Insufficient carnitine will not allow fatty acids to be moved to the right place and the body will eventually wear down, resulting in a person feeling drained and tired
Carnitine reduces the health risks posed by poor fat metabolism associated with diabetes; inhibits alcohol-induced fatty liver; and lessens the risk of heart disorders.
Studies have shown that damage to the heart from cardiac surgery can be reduced by treatment with carnitine. According to The American Journal of Cardiology, one study showed that proprionyl-L-carnitine, a carnitine derivative, helps to ease the severe pain of intermittent claudication, a condition in which a blocked artery in the thigh decreases the supply of blood and oxygen to leg muscles, causing pain, especially with physical activity.
Carnitine has the ability to lower blood triglyceride levels, aid in weight loss, improve the motility of sperm, and improve muscle strength in people with neuromuscular disorders.
Men normally require more carnitine than women, because of their heavier body mass
Many cases of carnitine deficiency have been identified as partly genetic in origin, resulting from an inherited defect in carnitine synthesis. Possible symptoms of deficiency include confusion, heart pain, muscle weakness, and obesity.
Citrulline is a nonessential amino acid, which means that it is manufactured from other amino acids in the liver; it does not have to be obtained directly through the diet. Citrulline is found in high concentration in the liver. Citrulline is not a component of any major proteins or enzymes. It is synthesized in the body from ornithine by the addition of CO2 and ammonia and is a precursor of arginine. Only the L form of amino acids are constituents of protein.
Citrulline exists primarily in the liver, where it is heavily involved in the urea cycle to detoxify and excrete ammonia. This unusual amino acid is formed in the urea cycle by the addition of carbon dioxide and ammonia to ornithine. Next, it is combined with aspartic acid to form arginosuccinic acid, which later is metabolized into the amino acid arginine. Citrulline is not a component of any major proteins or enzymes. This unusual amino acid is formed in the urea cycle by the addition of carbon dioxide and ammonia to ornithine. Next, it is combined with aspartic acid to form arginosuccinic acid, which later is metabolized into the amino acid arginine. Citrulline is not a component of any major proteins or enzymes.
Citrulline helps the immune system in fighting infections and increases energy.
Citrulline, through its conversion into another amino acid (arginine) in our body optimizes blood flow. Arginine allows for increased production of nitric acid in the endothelium, to support circulatory function.
Without citrulline it is not possible to detoxify liver cells from ammonia, which is a waste product of oxidation process.
It helps maintain the acid-base balance in the body.
It plays an important role in the production of arginine, which stimulates the secretion of human growth hormone and prolactin. Arginine helps in bodybuilding, in enhancing blood flow and in relieving stress.
Citrulline promotes the production of insulin, creatine and the growth hormone.
Watermelon, especially the melon rind is an excellent source of citrulline. Vegetables like pumpkins, cucumbers, gourds and squashes are also good sources of citrulline.
Besides vegetables, fruits such as cantaloupes, honeydews, bittermelons and muskmelons also contain citrulline in substantial amounts.
Walnut seedlings are considered to be the richest source of citrulline.
Citrulline is also abundantly found in fish, meat, eggs, milk, and legumes.
Foods rich in protein, also contain high amount of citrulline.
Glycine is a sweet-tasting, non-essential amino acid that can be produced from serine and threonine, which means that it is manufactured in the liver; it does not have to be obtained directly through the diet. Glycine was first isolated in 1820 from gelatin and is also found in good quantity in silk fibroin. Glycine is required to build protein in the body. It is required for the synthesis of nucleic acids, the construction of RNA as well as DNA and synthesis of bile acids and other amino acids in the body. Glycine is also found to be useful in assisting with the absorption of calcium in the body. It helps in retarding degeneration of muscles as it helps to supply extra creatine in the body. Glycine is important in the body’s manufacture of hormones responsible for a strong immune system.
Glycine is the simplest amino acid and is the only amino acid that is not optically active (it has no stereoisomers). This amino acid is essential for the biosynthesis of nucleic acids as well as of bile acids, porphyrins, creatine phosphate, and other amino acids. On a molar basis, glycine is the second most common amino acid found in proteins and enzymes being incorporated at the rate of 7.5 percent compared to the other amino acids. Glycine is also similar to gamma-aminobutyric acid and glutamic acid in the ability to inhibit neurotransmitter signals in the central nervous system.
Only the L form of amino acids are constituents of protein. Glycine is an important part of GTF (glucose tolerance factor). The prostate gland produces fluid that contains glycine and researchers think that it may have a positive influence on normal prostate function. It is present in considerable amounts in prostate fluid. Glycine may play a role in maintaining the health of the prostate, since a study of 45 men with benign prostatic hyperplasia (BPH) found that 780 mg of glycine per day for two weeks and then 390 mg for the next two and a half months, taken in combination with equal amounts of the amino acids, alanine and glutamic acid, reduced symptoms of the condition. This effect has been reported by others. Glycine also enhances the activity of neurotransmitters (chemical messengers) in the brain that are involved in memory and cognition.
Function and Benefits of Glycine
Glycine is used by the nervous system and functions as an inhibitory neurotransmitter, which makes it important to help prevent epileptic seizures
Glycine is also used in the treatment of manic depression and hyperactivity
Glycine also participates in the major energy producing biochemical processes in the body
This amino acid is also found to be produce in prostate fluid present in males so it is considered to be important for prostate normal functioning.
Glycine is the part of glutathione which is a coenzyme involved in many biochemical reactions. The important function of glutathione is that it helps in the maintenance of the cell integrity by protecting –SH group of hemoglobin, catalase and lipoproteins of the cell membrane. So glycine has an important antioxidant action.
Glycine is necessary for central nervous system function and a healthy prostate.
Deficiency Symptoms of Glycine
Few people are glycine deficient, in part because the body makes its own supply of the non-essential amino acids, and because it is abundant in food sources.
Glutathione is actually a compound classified as a tripeptide made up the amino acids gamma-glutamic acid, cysteine, and glycine and is also known as gamma-glutamylcysteinylglycine or GSH. Like carnitine, glutathione is not technically one of the amino acids. It is a compound classified as a tripeptide, and the body produces it from the amino acids cysteine, glutamic acid, and glycine. Because of its close relationship to these amino acids, however, it is usually considered together with them.
The primary biological function of glutathione is to act as a non-enzymatic reducing agent to help keep cysteine thiol side chains in a reduced state on the surface of proteins. Glutathione is also used to prevent oxidative stress in most cells and helps to trap free radicals that can damage DNA and RNA. There is a direct correlation with the speed of aging and the reduction of glutathione concentrations in intracellular fluids. As individuals grow older, glutathione levels drop, and the ability to detoxify free radicals decreases.
Supplemental glutathione is expensive, and the effectiveness of oral formulas is questionable. To raise glutathione levels, it is better to supply the body with the raw materials it uses to make this compound: cysteine, glutamic acid, and glycine. The N-acetyl form of cysteine, N-acetylcysteine (NAC), is considered particularly effective for this purpose
Function and Benefits of Glutathione
Glutathione is a powerful antioxidant and detoxifies harmful compounds in the liver, which is then excreted through bile.
Glutathione is also found in the lungs and the intestinal tract. It is needed for carbohydrate metabolism and appears to exert anti-aging effects, aiding in the breakdown of oxidized fats that may contribute to atherosclerosis.
A significant component of the collective antioxidant defenses, and a highly potent antioxidant and antitoxin in its own right.
Glutathione is a very important detoxifying agent, enabling the body to get rid of undesirable toxins and pollutants. It forms a soluble compound with the toxin that can then be excreted through the urine or the gut.
Glutathione is required in many of the intricate steps needed to carry out an immune response. For example, it is needed for the lymphocytes to multiply in order to develop a strong immune response, and for ‘killer’ lymphocytes to be able to kill undesirable cells such as cancer cells or virally infected cells.
Glutathione is a powerful antioxidant that is produced in the liver. The largest stores of glutathione are found in the liver, where it detoxifies harmful compounds so that they can be excreted through the bile. Some glutathione is released from the liver directly into the bloodstream, where it helps to maintain the integrity of red blood cells and protect white blood cells.
lutathione is the major antioxidant produced by the cell, protecting it from ‘free radicals’ (‘oxygen radicals‘, ‘oxyradicals’). These highly reactive substances, if left unchecked, will damage or destroy key cell components (e.g. membranes, DNA) in microseconds. Glutathione recycles other well-known antioxidants such as vitamin C and vitamin E, keeping them in their active state.
Deficiency Symptoms of Glutathione
A deficiency of glutathione first affects the nervous system, causing such symptoms as lack of coordination, mental disorders, tremors, and difficulty maintaining balance. These problems are believed to be due to the development of lesions in the brain.
A study sponsored in part by the National Cancer Institute found that people with HIV disease who had low glutathione levels had a lower survival rate over a three-year period than those whose glutathione levels were normal. As we age, glutathione levels decline, although it is not known whether this is because we use it more rapidly or produce less of it to begin with. Unfortunately, if not corrected, the lack of glutathione in turn accelerates the aging process.
Cysteine and Cystine are closely related; each molecule of cystine consists of two molecules of cysteine joined together. Cysteine is very unstable and is easily converted to L-cystine; however, each form is capable of converting into the other as needed. Both are sulfur containing amino acids that aid in the formation of skin and are important in detoxification. Cysteine is present in alpha-keratin, the chief protein constituent of the fingernails, toenails, skin, and hair. Cysteine aids in the production of collagen and promotes the proper elasticity and texture of the skin. It is also found in a variety of other proteins in the body, including several of the digestive enzymes.
Function and Benefits of Cysteine
It acts as precursor to glutathione which is an antioxidant. It therefore detoxifies the body from the free radical produced in the body which damages the cell membrane and DNA. The presence of these free radicals also results in number of disease like heart diseases or even cancers. So these needs to be eliminated which is done by cysteine.
Cysteine is closely related to cystine, as cystine consists of two cysteine molecules joined together
Cysteine is critical to the metabolism of a number of essential biochemicals – coenzyme A, heparin, biotin, lipoid acid, and glutathione
Cysteine is an unstable nutrient and easily converts to cystine, but this does not cause a problem, since both can convert into the other – as required by the body
Cysteine is needed for the skin and it performs detoxification action in the body as it is present in keratin which is the main protein found in the nails, hairs and skin.
Cysteine helps to detoxify harmful toxins and protect the body from radiation damage. It is one of the best free radical destroyers, and works best when taken with selenium and vitamin E.
Cysteine is also precursor to glutathione, a substance that detoxifies the liver by binding with potentially harmful substances there. It helps to protect the liver and brain from damage due to alcohol, drugs, and toxic compounds in cigarette smoke.
Stomach protection – cysteine has been found to help strengthen the protective lining of the stomach as well as intestines, which may help prevent damage caused by aspirin and similar drugs
Since cysteine is more soluble than cystine, it is used more readily in the body and is usually best for treating most illnesses. This amino acid is formed from L-methionine in the body. Vitamin B6, vitamin12 and folate are necessary for cysteine synthesis, which may not take place as it should in the presence of chronic disease.
Cystine can also be converted into glucose and used as a source of energy. Cystine strengthens the protective lining of the stomach and intestines, which may help prevent damage caused by aspirin and similar drugs. In addition, cystine may play an important role in the communication between immune system cells. Cystine is rarely used as a dietary supplement. N-acetyl cystine (NAC), which contains cystine, is more commonly used as a supplement.
Function and Benefits of Cystine
It is helpful in the healing of burns and wounds and helps break down mucus deposits in illnesses such as bronchitis and cystic fibrosis.
Cystine is a crystalline, sulphur-containing amino acid, formed from two molecules of the amino acid cysteine
Strengthens the protective lining of the stomach and intestines, which may help prevent damage caused by aspirin and similar drugs.
Functions as an antioxidant and is a powerful aid to the body in protecting against radiation and pollution.
Detoxification from cigarettes and alcohol – cystine has been shown as a detoxification agent to protect the body against damage of alcohol and cigarette smoking, and may be effective in preventing hangovers, as well as preventing liver and brain damage
Cystine or the N-acetyl form of cysteine (N-acetylcysteine, or NAC) may be used in place of L-cysteine. NAC aids in preventing side effects from chemotherapy and radiation therapy. Because it increases glutathione levels in the lungs, kidneys, liver, and bone marrow, it has an anti aging effect on the body-reducing the accumulation of age spots, for example. NAC has been shown to be more effective at boosting glutathione levels than supplements of cystine or even of glutathione itself.
Deficiency of cystine is rare, as it is found in so many protein foods, although in patients with chronic diseases, the synthesis of cystine from methionine appears to be prevented and could result in a deficiency.
People in these groups at risk of cystine deficiency should talk to a medical professional about cystine supplementation.
Proline is one of the cyclic aliphatic amino acids that is a major component of the protein collagen, the connective tissue structure that binds and supports all other tissues. Proline is synthesized from glutamic acid prior to its incorporation into pro-collagen during messenger RNA translation. After the pro-collagen protein is synthesized, it is converted by post-translational modification into hydroxyproline. On a molar basis proline is incorporated into protein at a rate of 4.2 percent with respect to other amino acids.
Proline improves skin texture and aids collagen formation and helps contain the loss of collagen during aging. Collagen in the skin contains hydroxyproline and hydroxylysine, which is formed from proline and lysine, in which ascorbic acid seems to be important in this conversion. Collagen contains about 15% proline. It is also thought to be important in the maintenance of muscles, joints and tendons.
Function and Benefits of Proline
Proline is associated with the production of collagen which promotes healthy skin, joints, tendons, and heart muscle.
The metabolism of proline is connected to enzymes that require niacin and vitamin C.
Helps strengthen cardiac muscle, improves skin texture and aids collagen formation and helps contain the loss of collagen during aging.
Proline gives rise to glutamic acid which is an important amino acid. This glutamic acid then gives rise to very important compounds such as glutathione, glutamine, gamma aminobutyric acid, alpha ketoglutarate etc.
Proline is interchangeable with the ornithine, thus it can lead to the formation of urea as well. On the other hand, ornithine has also been found to form proline.
Proline is also converted to hydroxyproline by post translation reaction that is after it has been incorporated into the protein molecule.
Thus, proline is also an important amino acid. Its supplements are also available in the market. These are especially important in those people who are suffering from diseases due to collagen deficiency and also in those suffering from skin disorders and injuries.
Collagen in the skin contains hydroxyproline and hydroxylysine, which is formed from proline and lysine, in which ascorbic acid seems to be important in this conversion. Collagen contains about 15% proline. It is also thought to be important in the maintenance of muscles, joints and tendons.
Rich food sources of Proline
It is not so needed to be obtained from the food as it is itself formed within our body. But it is richly present in the meat.
Serine is is a nonessential amino acid. Serine was first isolated in 1865 from sericin, a silk protein, it can be synthesized in the body from glycine , but this process requires the presence of sufficient amounts of vitamins B3 and B6 and folic acid. Glycine is converted into serine by the addition of hydroxymethyl group and this reaction is catalyzed by serine hydroxymethyl transferase enzymes which also requires the two coenzymes namely, tetrahydrofolate and pyridoxal phosphate.
Serine is required for the metabolism of fat, tissue growth and the immune system as it assists in the production of immunoglobulins and antibodies, and is a constituent of brain proteins and nerve sheaths. It is important in the production of cell membranes, and muscle tissue synthesis. It is important in RNA and DNA function, cell membrane formation, and creatine synthesis. Cancer-preventative. However, too-high serine levels in the body may have adverse effects on the immune system.
Function and Benefits of Serine
Serine is required for the metabolism of fat, tissue growth and the immune system as it assists in the production of immunoglobulins and antibodies. Some derivatives (e.g. ethanolamine) are also important components of the phospholipids found in biological membranes.
It performs an important function in the catalytic role of numerous enzymes, for example it has been found to occur in the active sites of trypsin, chymotrypsin and various other enzymes.
Serine is also utilized in the synthesis of tryptophan amino acid which then gives rise to important neurotransmitter the serotonin in the central nervous system. Their deficiency leads to depression, irritability, insomnia, anxiety and confusion.
Serine has found to increase the absorption of creatine. Creatine is important for muscles as it make them strong and increases their mass.
It is a component of brain proteins and the protective myelin sheaths that cover nerve fibers. It is important in RNA and DNA function, cell membrane formation, involved in the metabolism of purines and pyrimidines, and muscle synthesis
Serine can be made from glycine in the body, but this process requires the presence of sufficient amounts of vitamins B3 and B6 and folic acid
It is also used in cosmetics as a skin moisturizer.
Serine stimulates the synthesis of glucose (blood sugar) in the liver. For this reason, eating proteins foods that are rich in serine will help stabilize the body against oscillations of blood sugar levels after eating. Serine is known to be the precursor to cysteine, along with methionine.
Deficiency leads to depression, irritability, insomnia, anxiety and confusion.
Rich Food Sources of Serine
Animal origin sources: These include : meat, beef, dairy products like cheese etc.
Plant origin sources: These include : almonds, asparagus, chickpea, cow pea, flax-seed, lentils, sesame seed, walnut and soy beans.
Aspartic acid was first isolated in 1868 from legumin in plant seed. Aspartic acid, also called asparaginic acid, is one of the nonessential amino acids. “Nonessential” means that our bodies produce it even if we don’t get this amino acid from the food we eat.
Aspartic acid is one of two amino acids (the other is glutamic acid) that has a negatively charged carboxylate group on the side chain. This gives aspartic acid an overall negative charge at physiological hydrogen ion concentrations (approximately pH 7.3). Although aspartic acid is considered a non-essential amino acid, it plays a paramount role in metabolism during construction of other amino acids and biochemicals in the citric acid cycle. Among the biochemicals that are synthesized from aspartic acid are asparagine, arginine, lysine, methionine, threonine, isoleucine, and several nucleotides.
Function and Benefits of Aspartic Acid
Combines with other amino acids to form compounds that absorb and remove toxins from the bloodstream.
It has also found to play an important role in the neuroendocrine system for example in anterior pituitary it stimulates the following hormonal secretions of prolactin, growth hormone and luteinizing hormone
Because aspartic acid increases stamina, it is good for fatigue and depression, and plays a vital role in metabolism. Chronic fatigue may result from low levels of aspartic acid, because this leads to lowered cellular energy.
It is good for athletes and helps to protect the liver by aiding in the removal of excess ammonia.
It helps to move certain minerals across the intestinal lining and into the blood and cells, aids cell function, and aids the function of RNA and DNA, which are the carriers of genetic wormation.
It enhances the production of immunoglobulins and antibodies (immune system proteins). Plant protein, especially that found in sprouting seeds, contains an abundance of aspartic acid.
It also aids in the detoxification of liver from various drugs and chemicals.
Deficiency Symptoms of Aspartic Acid
Deficiency symptoms of Aspartic Acid may include fatigue and depression.