what amino acids in a protein are particularly reactive toward heavy metals?

Answer 1

Common Heavy Metals: Sources and Specific Effects
Aluminum, arsenic, cadmium, lead, mercury, and nickel are the most prevalent heavy metals. The specific sources of exposure, body tissues in which the metal tends to be deposited, and health effects of each metal are identified below.

1. Aluminum
Sources of exposure: Aluminum cookware, aluminum foil, antacids, antiperspirants, baking powder (aluminum containing), buffered aspirin, canned acidic foods, food additives, lipstick, medications and drugs (anti-diarrheal agents, hemorrhoid medications, vaginal douches), processed cheese, "softened" water, and tap water.

Target tissues: Bones, brain, kidneys and stomach.

Signs and Symptoms: Colic, dementia, esophagitis, gastroenteritis, kidney damage, liver dysfunction, loss of appetite, loss of balance, muscle pain, psychosis, shortness of breath, and weakness.

Among the patients I see in my practice, the highest aluminum exposure is most frequently due to the chronic consumption of aluminum-containing antacid products. Research shows that aluminum builds up in the body over time; thus, the health hazard to older people is greater.

D.R. McLaughlin, M.D., F.R.C.P. (C), professor of physiology and medicine and director of the Centre for Research in Neurodegenerative Diseases at the University of Toronto, states, "Concentrations of aluminum that are toxic to many biochemical processes are found in at least ten human neurological conditions."10 Recent studies suggest that aluminum contributes to neurological disorders such as Alzheimer's disease, Parkinson's disease, senile and presenile dementia, clumsiness of movements, staggering when walking, and inability to pronounce words properly.11 Behavioral difficulties among schoolchildren have also been correlated with elevated levels of aluminum and other neurotoxic heavy metals.

2. Arsenic
Sources of exposure: Air pollution, antibiotics given to commercial livestock, certain marine plants, chemical processing, coal-fired power plants, defoliants, drinking water, drying agents for cotton, fish, herbicides, insecticides, meats (from commercially raised poultry and cattle), metal ore smelting, pesticides, seafood (fish, mussels, oysters), specialty glass, and wood preservatives.

Target tissues: Most organs of the body, especially the gastrointestinal system, lungs, and skin.

Signs and Symptoms: Abdominal pain, burning of the mouth and throat, cancer (especially lung and skin), coma, diarrhea, nausea, neuritis, peripheral vascular problems, skin lesions, and vascular collapse.

The greatest dangers from chronic arsenic exposure are lung and skin cancers and gradual poisoning, most frequently from living near metal smelting plants or arsenic factories.

3. Cadmium
Sources of exposure: Air pollution, art supplies, bone meal, cigarette smoke, food (coffee, fruits, grains, and vegetables grown in cadmium-laden soil, meats [kidneys, liver, poultry], or refined foods), freshwater fish, fungicides, highway dusts, incinerators, mining, nickel-cadmium batteries, oxide dusts, paints, phosphate fertilizers, power plants, seafood (crab, flounder, mussels, oysters, scallops), sewage sludge, "softened" water, smelting plants, tobacco and tobacco smoke, and welding fumes.

Target tissues: Appetite and pain centers (in brain), brain, heart and blood vessels, kidneys, and lungs.

Signs and Symptoms: Anemia, dry and scaly skin, emphysema, fatigue, hair loss, heart disease, depressed immune system response, hypertension, joint pain, kidney stones or damage, liver dysfunction or damage, loss of appetite, loss of sense of smell, lung cancer, pain in the back and legs, and yellow teeth.

Current studies are attempting to determine if cadmium-induced bone and kidney damage can be prevented (or made less likely) by adequate calcium, protein (amino acids), vitamin D, and zinc in the diet.12

4. Lead
Sources of exposure: Air pollution, ammunition (shot and bullets), bathtubs (cast iron, porcelain, steel), batteries, canned foods, ceramics, chemical fertilizers, cosmetics, dolomite, dust, foods grown around industrial areas, gasoline, hair dyes and rinses, leaded glass, newsprint and colored advertisements, paints, pesticides, pewter, pottery, rubber toys, soft coal, soil, solder, tap water, tobacco smoke, and vinyl 'mini-blinds'.

Target tissues: Bones, brain, heart, kidneys, liver, nervous system, and pancreas.

Signs and Symptoms: Abdominal pain, anemia, anorexia, anxiety, bone pain, brain damage, confusion, constipation, convulsions, dizziness, drowsiness, fatigue, headaches, hypertension, inability to concentrate, indigestion, irritability, loss of appetite, loss of muscle coordination, memory difficulties, miscarriage, muscle pain, pallor, tremors, vomiting, and weakness.

The toxicity of lead is widely acknowledged. The greatest risk for harm, even with only minute or short-term exposure, is to infants, young children, and pregnant women. A federal study conducted by the Centers for Disease Control and Prevention (CDCP) in 1984 estimated that three to four million American children have an unacceptably high level of lead in their blood. Dr. Suzanne Binder, a CDCP official, stated, "Many people believed that when lead paint was banned from housing [in 1978], and lead was cut from gasoline [in the late 1970s], lead-poisoning problems disappeared, but they're wrong. We know that throughout the country children of all races, and ethnicities and income levels are being affected by lead [already in the environment]."13 In their book, 'Toxic Metal Syndrome', Dr.'s R. Casdorph and M. Walker report that over 4 million tons of lead is mined each year and existing environmental lead levels are at least 500 times greater than pre-historic levels.

In 1989, the U.S. Environmental Protection Agency (EPA) reported that more than one million elementary schools, high schools, and colleges are still using lead-lined water storage tanks or lead-containing components in their drinking fountains.14 The EPA estimates that drinking water accounts for approximately 20% of young children's lead exposure.15 Other common sources are lead paint residue in older buildings (as in inner cities) and living in proximity to industrial areas or other sources of toxic chemical exposure, such as commercial agricultural land. All children born in the U.S. today have measurable traces of pesticides, a source of heavy metals and chlorine-based chemicals, in their tissues.16

Lead is a known neurotoxin (kills brain cells), and excessive blood lead levels in children have been linked to learning disabilities, attention deficit disorder (ADD), hyperactivity syndromes, and reduced intelligence and school achievement scores.17

5. Mercury
Sources of exposure: Air pollution, batteries, cosmetics, dental amalgams, diuretics (mercurial), electrical devices and relays, explosives, foods (grains), fungicides, fluorescent lights, freshwater fish (especially large bass, pike, and trout), insecticides, mining, paints, pesticides, petroleum products, saltwater fish (especially large halibut, shrimp, snapper, and swordfish), shellfish, and tap water.

Target tissues: Appetite and pain centers in the brain, cell membranes, kidneys, and nervous system (central and peripheral).

Signs and Symptoms: Abnormal nervous and physical development (fetal and childhood), anemia, anorexia, anxiety, blood changes, blindness, blue line on gums, colitis, depression, dermatitis, difficulty chewing and swallowing, dizziness, drowsiness, emotional instability, fatigue, fever, hallucinations, headache, hearing loss, hypertension, inflamed gums, insomnia, kidney damage or failure, loss of appetite and sense of smell, loss of muscle coordination, memory loss, metallic taste in mouth, nerve damage, numbness, psychosis, salivation, stomatitis, tremors, vision impairment, vomiting, weakness, and weight loss.

The primary source of exposure to mercury is "silver" dental fillings (approximately 50% mercury when placed); over 225 million Americans have these fillings in their teeth.18 Mercury fillings release microscopic particles and vapors of mercury every time a person chews. Vapors are inhaled while particles are absorbed by tooth roots, mucous membranes of the mouth and gums, and the stomach lining.

In people with mercury amalgam fillings, measurements of the mercury level in the mouth ranges between 20 and 400 mcg/m3. Keep in mind that this is continuous exposure. The National Institute of Occupation Safety and Health places the safe limit of environmental exposure to mercury at 20 mcg/m3, but that is assuming a weekly exposure of 40 hours (the workweek) and the mercury involved is outside the body.19 The Environmental Protection Agency's allowable limit for continuous mercury exposure is 1 mcg/m3 but, again, that is based on mercury sources outside the body.20 Neither figure addresses 24-hour-a-day exposure from mercury in one's mouth.

Hal Huggins, D.D.S., a specialist in the effect of mercury amalgams on health, reports that 90% of the 7,000 patients he tested showed immune system reactivity from exposure to low levels of mercury. In 1984, the American Dental Association (ADA), without providing scientific evidence, claimed that only 5% of the U.S. population is reactive to mercury exposure, and that this figure is insignificant. Meanwhile, the ADA mandates that dentists alert all dental personnel to the potential hazards of inhaling mercury vapors.21 The Environmental Protection Agency (EPA) goes further, instructing dentists to treat mercury amalgam as a toxic material while handling before insertion, and as toxic waste after removal.22

Mark S. Hulet, D.D.S., who conducts research on amalgam fillings, wrote a pamphlet for his patients, in which he cites five categories of pathological reaction to mercury fillings, as identified by dentists, doctors, and toxicologists. The categories are:
• Neurological: emotional manifestations (depression, suicidal impulses, irritability, inability to cope) and motor symptoms (muscle spasms, facial tics, seizures, multiple sclerosis)
• Cardiovascular problems: nonspecific chest pain, accelerated heart beat
• Collagen diseases: arthritis, bursitis, scleroderma, systemic lupus erythematosis
• Immune system diseases: compromised immunity
• Allergies: Airborne allergies, food allergies, and "universal" reactors.
One of the keys to mercury's effects on health may be its ability to block the functioning of manganese, a key mineral required for physiological reactions in all five categories, notes Dr. Hulet.23

6. Nickel
Sources of exposure: Appliances, buttons, ceramics, cocoa, cold-wave hair permanent, cooking utensils, cosmetics, coins, dental materials, food (chocolate, hydrogenated oils, nuts, food grown near industrial areas), hair spray, industrial waste, jewelry, medical implants, metal refineries, metal tools, nickel-cadmium batteries, orthodontic appliances, shampoo, solid-waste incinerators, stainless steel kitchen utensils, tap water, tobacco and tobacco smoke, water faucets and pipes, and zippers.

Target tissues: Areas of skin exposure, larynx (voice box), lungs, and nasal passages.

Signs and Symptoms: Apathy, blue-colored lips, cancer (especially lung, nasal, and larynx), contact dermatitis, diarrhea, fever, headaches, dizziness, gingivitis, insomnia, nausea, rapid heart rate, skin rashes (redness, itching, blisters), shortness of breath, stomatitis, and vomiting.

The greatest danger from chronic nickel exposure is lung, nasal, or larynx cancers, and gradual poisoning from accidental or chronic low-level exposure, the risk of which is greatest for those living near metal smelting plants, solid waste incinerators, or old nickel refineries.24

How can we Protect Ourselves from Heavy Metals?
Logic dictates that, once the potential harm from heavy metals is understood, their production and use should be phased out and toxic storage heavily regulated. As is obvious from the list of exposure sources above, logic is not the guiding principle here, except in the case of lead, the use of which has been curtailed.

Even if all heavy metal production were to stop today, however, enough heavy metals have been released into our environment to cause chronic poisoning and numerous neurological diseases for generations to come. There are presently 600,000 toxic waste contamination sites in the United States alone, according to the U.S. Congressional Office of Technology Assessment. Of these, less than 900 have been proposed by the EPA for Superfund cleanup and approximately 19,000 others are under review. While some of these toxic messes were likely caused by accidents or ignorance, the majority came from illegal dumping by hazardous product or waste distributors, manufacturers, transportation companies, or waste management companies.25 Such practices have not ceased, as focus on profit continues to override concerns about health, the environment, and a more promising future for all of our children.

With the government doing little or moving very slowly to protect the public from the hazards of heavy metals, it is up to individuals to take measures to protect themselves. According to conventional medicine, there is nothing a person can do to address aluminum, arsenic, cadmium, lead, mercury, or nickel exposure, aside from avoiding known sources. Given the prevalence of these toxins in our lives, this is impossible.
Fortunately, there is a way to get these harmful substances out of the body. Intravenous and oral chelation, detoxification protocols, and specific nutritional therapies can remove heavy metals and chemical toxins and reduce the toxic load our bodies endure on a daily basis.

The Chelation Solution
Chelating (pronounced key-layting) agents are substances which can chemically bond with, or chelate (from the Greek chele, claw), metals, minerals, or chemical toxins from the body. The chelating agent actually encircles a mineral or metal ion and carries it from the body via the urine and feces.26 Many organic acids found in the body or in foods can act as chelating agents, including acetic acid, ascorbic acid (vitamin C), citric acid, and lactic acid. Natural chelation processes in the body are responsible for such things as the digestion, assimilation, and transport of food nutrients, the formation of enzymes and hormones, and detoxification of toxic chemicals and metals.27

Intravenous chelation therapy involves injecting the chelating agent EDTA into the bloodstream for the purpose of eliminating from the body undesirable substances such as heavy metals, chemical toxins, mineral deposits, and fatty plaques (as in the arteries; the agent binds to the calcium in the plaques). EDTA (ethylene diamine tetraacetic acid) is an effective and widely studied chelating agent. It cannot chelate mercury, however, DMSA and DMPS, the chemicals which work intravenously to chelate mercury, are not approved by the FDA.

EDTA is a synthetic amino acid (amino acids are the building blocks of protein) and is approximately one third as toxic to the body as aspirin.28 Chelation therapy with EDTA was first introduced into medicine in the United States in 1948 as a treatment for the lead poisoning of workers in a battery factory. Shortly thereafter, the U.S. Navy advocated chelation for sailors who had absorbed lead while painting government ships and facilities. The FDA approved IV EDTA chelation as a treatment for lead poisoning.
Physicians administering the chelation for lead toxicity observed that patients who also had atherosclerosis (fatty-plaque buildup on arterial walls) or arteriosclerosis (hardening of the arteries) experienced reductions in both conditions after chelation.29 Since 1952, IV EDTA chelation has been used to treat cardiovascular disease.

Answer 2

because they exist in ZWITTER ION state