AMINO ACIDS
When we eat a meal we don't pay much attention to the content and balance of amino acids but the content of the meal determines the body and health building value of the protein food or supplement.
- Aromatic Amino Acids
- Acidic Amino Acids
- Basic Amino Acids
- Sulfur - Containing Amino Acids
- Imino Amino Acids
- Glycine – The most abundant amino acid in collagen and the smallest side chain.
- Alanine – The most abundant amino acid.
- Valine - Is a precursor to acetyl Co-A, which is the beginning of both the formation of cholesterol in the body and the T.C.A. cycle, which provides energy for cellular metabolism (and learning it was and is the source of great consternation for high school and college students of today and yesteryear).
- Leucine
- Isoleucine
- Cysteine
- Methionine
- Phenylalanine
- Tyrosine
- Tryptophan
- Serine
- Threonine
- Asparagine
- Glutamine
- Aspartic acid
- Glutamic acid
- Histidine
- Lysine
- Arginine
- Proline
Essential Amino Acids
There are 10 essential amino acids, so called because the human body cannot make them and therefore you must get them from your diet.
These are:
- Histidine
- Isoleucine
- Leucine
- Methionine
- Phenylalanine
- Threonine
- Tryptophan
- Valine
- Arginine – fits into both categories
Non-Essential Amino Acids
- Alanine
- Arginine
- Asparagine
- Aspartate
- Cysteine
- Glutamate
- Glutamine
- Glycine
- Proline
- Serine
- Tyrosine
Proteins are rated based on the content of their essential amino acids. For example, egg white, which is pure albumin and pure protein, has the highest score: 100. Interestingly, the German name for protein is eiweiss, which, if you translate it literally, means “egg white.” Threonine has a score of 40 and lysine has a score of 100. The RDA for the average American is 0.8mg/kg. Since one kilogram is approximately equal to two pounds, and if the average person in America weighs 150 pounds (and we know that’s not true), then 150 x 0.8 = 120mg/day of protein. That would be your daily requirement for protein intake. What I would like to do now is go through all of these and give a brief description of what each one does and what effect it can have on our bodies.
Alanine
Alanine is most notable for the glucose-alanine cycle. This is where alanine is released from muscle stores into the blood circulation. It is then taken up by the liver and converted to pyruvate, which then turns into sugar, and a nitrogen molecule is released which then attaches to urea for urinary excretion. The sugar then goes back to the muscle, and the cycle starts over again. That is why alanine is considered the most important amino acid taken up by the liver for the making of glucose. Alanine, which has a very high concentration in muscle, represents about 25% of the amino acids released from muscle tissue. The implication is obvious: When the muscles start working and you need sugar, they provide a ready supply of energy. Therefore, the more toned the muscles, the greater the regulation of that form of sugar.
Arginine
This amino acid has the most basic of (pH) properties. The urea cycle is all about getting rid of the byproducts of metabolism. This is done by forming urea and then eliminating it through the kidneys in the form of urine. There is a chemical called n-acetyl glutamate, which is the main regulator of this entire cycle. However, it is arginine that stimulates n-acetyl glutamate. Therefore, it can be said it is very important in the regulation of getting rid of the byproducts of metabolism. If the enzyme arginase is absent, then arginine tends to build up in the body, which can lead to mental retardation, spastic muscle movements and seizures. Arginine also serves as a facilitator of a brain transmitter called agmatine, which helps regulate brain function. Nitrous oxide is an indispensable protein necessary for wound healing, and argentine is required for the synthesis of nitrous oxide.
Many supplements tout arginine as a potent stimulator of growth hormone release. In fact, as a father, I can remember my two boys pumping themselves up with weights and arginine getting ready for spring break and – I might add – with remarkable results. Current thinking was that this worked only in very young adults (18- to 24-year-olds), but as we got older (over 40), it did not. Coillier (13) did a study giving 18- to 33-year-olds five, nine and 13 grams of oral arginine and then measured their growth hormone levels. The results were that five and nine grams did raise their growth hormone levels, but at the 13-gram dose most of the subjects were extremely nauseated. So, arginine is capable of raising your growth hormone levels if taken in conjunction with a lot of weight lifting.
Aspartate
Aspartate
serves as a donor of a nitrogen atom, which is incorporated into urea, which
can then be eliminated via the kidneys. There are two types of proteins known
as purines and pyrimidines. These are made up of amino acids, specifically
adenine and guanine for purine proteins and uridine, thymidine and cytosine for
pyrimidine proteins – all of these amino acids are in some way synthesized from
aspartate. So, it is involved in the elimination of waste products from the
body and as an intermediary for the production of most proteins. Most of you
know aspartame as an artificial sweetener.
Citrulline
Citrulline
is an amino acid that is made from other amino acids in the small intestines.
It is then transported to the kidneys, where it is converted to arginine (see
above), which is essential for the formation of urea. The enzyme that does this
is called argininosuccinate synthetase. If this enzyme is missing, then
citrulline builds up in the blood and leads to mental retardation, enlarged
liver and seizures. The bottom line with citrulline is that it is an
intermediate amino acid in the urea cycle.
Cysteine
Cysteine is one of two amino acids that are classified as sulfur-containing amino acids (the other is methionine). It plays a critical role in the stabilization of protein structures. It is an important amino acid in that the improper metabolism of this amino acid leads to critical disease states. In the liver, the sulfur atom is raised to a higher charge and then a carbon atom is cleaved. The result is the making of homocysteine. Many of you are aware that it is one of the highest risk factors in heart disease to have a high homocysteine level. Elevated levels in an embryo can lead to improper closure of the spinal column leading to neurological problems in the newborn. In people who make too much homocysteine, it can lead to early atherosclerosis, blood clots, and, in children, mental retardation. Cysteine is metabolized to many products; one of them is taurine. Taurine is thought to be necessary for eye and sight development and is found in high concentrations in human milk. It is also added to most infant formulas in the U.S. Cysteine can be made from serine, but it must get its sulfur atom from methionine, which is an essential amino acid. So, some people will put it in the essential amino acid group, and some not.
A large amount of cysteine is used to make glutathione. This substance offers a very high degree of protection from oxidative damage from hydrogen peroxide, which is a powerful oxidant. Glutathione is also a powerful in-activator of other free radicals. Further problems with cysteine metabolism can be found if it is unable to metabolize to all of its other metabolites. If it builds up, it can cause cystine stones in the kidneys, which can destroy them. In summary, if there is a deficit in the normal metabolism and conversion of cysteine, it can have very wide and profound effects on your health.
Glutamine
Ammonia is a very toxic substance if allowed to build up in the body. Glutamine is unique in that it can serve as a buffer between the utilization of ammonia, as a source of ammonia, and as a carrier of ammonia. Because it has such a key role in transporting ammonia within the liver and other organs, it is found in very high concentrations in the blood and is the most abundant alpha-amino acid in the body, with more than 90% of it being within the cells themselves.
Most of you have heard of “Chinese restaurant syndrome.” This is the headache effect that monosodium glutamate has on the brain. While that causes no ill effects, it can also trigger asthma, which can have disastrous effects.
Glutamine is very important in the intestines. It is the principal source of energy, causes growth of the cells lining the intestines and, if one fasts excessively, the intestinal cells wither. This is completely reversible with glutamine. In the thymus gland, the “T” and “B” cells use glutamine as their primary source of energy. Glutamine is used by the kidneys to help control the body’s acid–base balance so that it can produce ammonia, glucose or bicarbonate to maintain homeostasis (body balance).
Glutamine is the precursor to GABA (gamma-amino-butyric-acid), one of the brain’s most important inhibitory neurotransmitters.
Glutamine
also donates a nitrogen atom to form amino sugars, which are necessary for most
cycles in the body (e.g., the urea cycle and the TCA or Krebs cycle).
Glycine
Glycine
is considered a non-essential amino acid and is derived from serine. One of its
functions is as a neurotransmitter. It works in the spinal cord and brain stem,
where it regulates impulses traveling down the spinal cord to the muscles.
Glycine is considered one of the major neuroinhibitory peptides in the central
nervous system. It is considered a very essential amino acid in premature
babies. Milk contains a very small amount of this, and it is thought that all
preemies should get supplementation to help in their neurological growth.
Glycine is responsible for the production of serine in the kidneys. It is used
to make bile in the liver and combines with benzoic acid in the kidneys to help
excrete urea. Because of its small molecular size, it is incorporated into the
tight triple-helical structure of collagen, and every third amino acid is a
glycine.
Histidine
Histidine is an essential amino acid and cannot be synthesized in humans. The sources are vegetables, nuts, gelatin, cereals, eggs, meat and fish. Histidine is metabolized to histamine, which is vital for normal body function. It is preferentially stored in the mast cells. If there is too much histamine or it is released too easily, hives and itching ensue. Excess release can also cause asthma. In the stomach, it stimulates the parietal cells to secrete acid, which can result in stomach and duodenal ulcers. Hence, the use of antihistamines and drugs like Tagamet control symptoms of itching and ulcers.
Histidine is stored in the body in the form of carnosine and in times of protein depletion, some of this carnosine can be reconverted to histidine to meet the needs of the body. I guess one could call this a pseudo-endogenous source of histidine.
Isoleucine
Isoleucine
is an essential amino acid with a wide and large source in nature. The entire
bean and pea family is rich in it, as are all dairy products, meat and fish.
Leucine
Leucine is abundant in nature. Whole-grain maize is exceptionally high in it. Most of the bean family has high amounts, but lentils, eggs, meat and fish are especially high in leucine. It is involved in the binding of proteins to DNA for transcription. There is a disease called maple syrup urine disease, which can be caused by the inability of the body to break down leucine, isoleucine and/or valine. It gets its name from the fact that the urine smells like maple syrup. The treatment is to avoid foods that are high in the above amino acids, eat a low-protein diet and take high doses of thiamine (vitamin B1). If left undiagnosed and untreated, this can lead to mental and physical retardation. It is the molecule which, when attached to enkephalins (a neurotransmitter) in the brain, determines our mood to a great extent.
Lysine
Lysine is found in highest concentration in meats, fish, wheat germ, lentils and beans.
Methionine
The
most abundant source of methionine in nature is in Brazil nuts. Other sources
are cauliflower, beets and eggs. Homocysteine is a very strong marker for
cardiac disease. The higher the homocysteine levels, the greater the chance of
an adverse cardiac event. Homocysteine is converted to methionine via B12. If
there is not enough B12, then the conversion does not occur and homocysteine
levels rise. Methionine is attached to an enkephalin in the brain and is at the
center of understanding brain neuropeptides (proteins that act in the brain).
Ornithine
Ornithine is one of the key intermediates in the production of proline, which is one of the cornerstones in the production of collagen. Ornithine is primarily made from arginine.
Phenylalanine
Dietary sources are very important with this amino acid. The highest amounts are found in beans, beets, lentils, soybeans, almonds, most nuts, almost all cereals (barley, wheat, oats, maize and rice), eggs and meats. The low-level sources are beets, cabbage and gelatin). The reason this is so important is that phenylalanine is converted to tyrosine via an enzyme called phenylalanine hydroxylase. This enzyme can be genetically missing, in which case the phenylalanine builds up and causes irreversible central nervous system damage. This is known as an “inborn error of metabolism” and this one is known as PKU (phenylketonuria). In occidental countries, it is mandatory that all children born in a hospital be checked for this disease. Early dietary restriction can completely eliminate this irreversible cause of mental retardation. The incidence of this in the U.S is about 1/10,000 births and the frequency of mutation in our culture is 1%. Of all diseases caused by inborn errors of metabolism (which all lead to some form of mental retardation), this one is the most frequent.
A
second inborn error of metabolism can occur with phenylalanine. Homogentisic
acid is one of the breakdown products of phenylalanine. If the enzyme that
oxidizes this acid is missing, we get a disease called black urine disease, so called
because if you let urine stand out for a while, it turns black. The incidence
of this is about one in a million. The primary symptom is arthritis that shows
up in mid-life and the only known partial treatment for it is high doses of
vitamin C.
Proline
With
the exception of beans, almost all vegetables contain proline. Cereals are very
high in proline, as are dairy products. Gelatin is by far the richest source of
proline. Almost two-thirds of collagen is made up of proline and
hydroxylproline, and that appears to be its principal role in the body. It is
found in high concentrations in cereals (whole-wheat and white flour) and
gelatin. When you hear the word proline, think collagen.
Serine
Serine breaks down to form glycine, which is a major contributor to making ammonia in the kidneys, forming about 5% of urinary ammonia. Also by forming glycine, it allows the latter to form sugar (energy) in the liver. Serine is also a precursor to phosphatidylserine, which is a major neurotransmitter and one of the only compounds that increases the uptake of oxygen and glucose by the brain’s cortex (the outer layer with which you think). In other words, it is a powerful memory stimulator. Phosphatidylserine, Lipoic acid and the hormone pregnenolone are the three most powerful over-the-counter memory enhancers on the market today. They have also been used effectively to prevent post-anesthesia memory loss. It is found in high concentrations in soybeans, hazelnuts, eggs and white rice.
Taurine
Taurine is used in the liver to help make bile. If low levels are present during pregnancy, retardation can occur. Because of that, taurine is added to infant formulas in the U.S.
Threonine
Threonine is an essential amino acid about which not much is known. Its ultimate fate in humans is thought to be broken down to form CO2. Threonine is widely abundant in nature, with good levels in most vegetables, most nuts, all cereals, dairy products, meats and fish.
Tryptophan
Tryptophan is the beginning amino acid in the formation of 5-hydroxytryamine, an important neurotransmitter. It is also converted to another neurotransmitter, serotonin, which can then be converted to melatonin in the brain, which controls the wake/sleep cycle. The latter is also one of the most powerful brain antioxidants there is. It is also the precursor amino acid in the formation of niacin, which helps lower blood cholesterol levels. This amino acid is found in low concentrations in almost all food sources, but the highest concentrations are found in coconuts and egg whites.
Tyrosine
We have already mentioned that a deficiency
in metabolism of phenylalanine causes mental retardation. The treatment for
this is supplementing the diet with tyrosine, which alleviates the retardation.
Alkaptonuria is another condition known as an “inborn error of metabolism.” In
individuals with this condition, almost all of their ingested tyrosine is
excreted in the urine. The urine from these people, if let standing, turns a
very dark brown color. Usually these people have this dark pigmentation accumulate
in their cartilage tissue in the third or fourth decades of life. They also
usually get a rather severe form of arthritis. The treatment is ascorbic acid (vitamin
C). Tyrosine is also converted to DOPA (Dihydroxyphenyl alanine), which is then
turned into dopamine. This is a neurotransmitter, which, if depleted in certain
areas of the brain, causes Parkinson’s disease. Another pathway that can be
taken is tyrosine metabolized to DOPA, which can then be converted to
norepinephrine. The latter is not only a neurotransmitter but also the
adrenaline that is released at the ends of our nerves. Tyrosine is an essential
amino acid and can be found in high concentrations in peas, rice, rye and dairy
products.
Valine
Valine is one of the most abundant amino acids, making up about 25% of our diet. Valine can be metabolized to form a product called acetyl-CoA. The CoAs (coenzyme A) are the starting material for cholesterol synthesis, steroids (most hormones are made from these), coenzymes CoQ-10 (the energy packets mainly in the heart) and act as detoxifiers of drugs in the body.
It is amazing to me that all of the above amino acids are in high concentrations in bovine colostrum. Think of all of the deficiency syndromes I have described and how all of them can be avoided or helped with nature’s best supplement.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.