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.
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.
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.
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.
Asparagine, created from another amino acid, aspartic acid, is needed to maintain balance in the central nervous system; it prevents you from being either overly nervous or overly calm. As it is converted back into aspartic acid, asparagine releases energy that brain and nervous system rells use for metabolism. It promotes the process by which one amino acid is transformed into another in the liver.
Function and Benefits of Asparagine
Our central nervous system also requires this amino acid where it helps in maintenance of balance or equilibrium. It is also essential for the proper functioning and health of our nerves and other cells of the body. It controls their metabolism in the brain.
Asparagine gives rise to aspartic acid by the reversal reaction and also gives rise to ammonia. This reaction is catalyzed by asparaginease. Aspartic acid can then be converted into oxaloacetic acid which enters the citric acid cycle then. Ammonia formed then gives rise to urea.
Asparagine is a non-essential amino acid that the body can manufacture in the liver. Only the L form of amino acids are constituents of protein.
Asparagine, the beta-amido derivative of aspartic acid, is considered a non-essential amino acid. This amino acid plays an important role in the biosynthesis of glycoproteins and is also essential to the synthesis of a large number of other proteins. On a per-mole basis, asparagine is incorporated into proteins and enzymes at a rate of 4.4 percent with respect to the other amino acids.
Deficiency Symptoms of Asparagine
Deficiency symptoms of asparagine can lead to confusion, headaches, depression, irritability, or, in extreme cases, psychosis.
Plant sources: asparagus, potatoes, legumes, nuts, seeds, soy, whole grains. Asparagine is found in potatoes so eating French fries will give you asparagine along with starch. It is also found on roasted coffee.
Ornithine plays an important role in the urea cycle and is the precursor of the amino acids citrulline, glutamic acid, and proline. Another primary role of ornithine is being an intermediate in arginine biosynthesis, although this is due to its participation in the urea cycle (responsible for the production of urea). Ornithine is not directly incorporated into proteins and enzymes and does not have a codon in the genetic code.
Functions and Benefits of Ornithine
Induces the release of growth hormone in the body, which in turn helps with fat metabolism. It is required for a properly functioning immune system and liver and assists in ammonia detoxification and liver rejuvenation. Helps in healing and repairing skin and tissue.
Ornithine is necessary for proper immune-system and liver function.
High concentrations of ornithine are found in the skin and connective tissue, making it useful for promoting healing and repairing damaged tissues.
Ornithine is synthesized in the body from arginine, and in turn serves as the precursor of citrulline, proline, and glutamic acid.
Animal research has suggested that ornithine, along with arginine, may promote muscle-building activity in the body by increasing levels of growth-promoting (anabolic) hormones such as insulin and growth hormone. However, most human research does not support these claims at reasonable intake levels. One study that did demonstrate increased growth hormone with oral ornithine used very high amounts (an average of 13 grams per day) and reported many gastrointestinal side effects. One controlled study reported greater increases in lean body mass and strength after five weeks of intensive strength training in athletes taking 1 gram per day each of arginine and ornithine, compared with a group doing the exercise but taking a placebo. These findings require independent confirmation.
Ornithine aspartate has been shown to be beneficial in people with brain abnormalities (hepatic encephalopathy) due to liver cirrhosis. In a double-blind trial, people with cirrhosis and hepatic encephalopathy received either 18 grams per day of L-ornithine-L-aspartate or a placebo for two weeks. Those taking the ornithine had significant improvements in liver function and blood tests compared with those taking the placebo.
Valine is a member of the branched-chain amino acid family, along with leucine and isoleucine. The three branched-chain amino acids constitute approximately 70 percent of the amino acids in the body proteins. As such, their value in the formation and maintenance of structural and functional integrity in humans is unmeasured. Valine is an amino acid obtained by hydrolysis of proteins and was first isolated by the German chemist Emil Fischer in 1901 from casein and is not only an essential amino acid but is also a branched-chain amino acid ( the others are isoleucine and leucine) found in high concentration in the muscles.
Valine is an aliphatic amino acid that is closely related to leucine and isoleucine both in structure and function. These amino acids are extremely hydrophobic and are almost always found in the interior of proteins. They are also seldom useful in routine biochemical reactions, but are relegated to the duty of determining the three-dimensional structure of proteins due to their hydrophobic nature. They are also essential amino acids and must be obtained in the diet. Valine is incorporated into proteins and enzymes at the molar rate of 6.9 percent when compared to the other amino acids.
Function and Benefits of Valine
Valine, an essential amino acid, has a stimulant effect. It is needed for muscle metabolism, tissue repair, and the maintenance of a proper nitrogen balance in the body.
It is one of the branched-chain amino acids, which means that it can be used as an energy source by muscle tissue.
It may be helpful in treating liver and gallbladder disease, and it is good for correcting the type of severe amino acid deficiencies that can be caused by drug addiction.
Valine has some stimulating effects. It plays role in the muscle metabolism and also helps in growth and repair of tissues. Valine also maintains nitrogen balance in our body.
Valine is the glucogenic amino acid so it provides glucose.
A disease known as maple serum urine disease results in case of error in metabolism of valine and it is then excreted in the urine.
Valine is found in high concentrations in muscle tissue.
Promotes mental vigor, muscle coordination and calm emotions.