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Sulfur Metabolism
study notes in progress
(items particularly applicable to me are in orange)
Sulfur is needed by every cell in the body.
The more I study my health problems, the clearer it is that problems with sulfur are fundmental.
Found in
- amino acids
- methionine and cysteine, important for detoxification of the blood
- taurine, which acts as a "dock" for sulfur [what does that mean?]
- Sulfur-rich foods
- A few sulfur compounds important to the human body:
- chondroitin - a major component of cartilage; helps keep it resilient by absorbing water. Also accelerates bone mineralization & bone repair. (Biochemical basis of the pharmacologic action of chondroitin sulfates on the osteoarticular system. Bali JP, Cousse H, Neuzil E.)
- heparin - a glycosaminoglycan blood anticoagulant produced by the liver
- fibrinogen - a large plasma protein molecule, essential for blood clotting.
- thiamine (vitamin B1): thiamin pyrophosphate participates as a coenzyme in the decarboxylation of both alpha-ketoglutarate and pyruvate, and in transketolase reactions. Important to skin
- biotin - necessary for four different carboxylases (enzymes) to catalyze their specific metabolic reactions. Can only be synthesized by bacteria, yeasts, molds, algae, and some plant species. Important to hair.
- beta-keratin - the main protein in nails, skin and hair. Contains cysteine.
- lipoic acid - a coenzyme involved in the decarboxylation of pyruvic acid and other keto acids
- coenzyme A directly involved in the metabolism of carbohydrates, proteins, and lipids, and plays a role in all the energy-requiring processes of the body
- Oxytocin (the "love hormone") - has a disulfide linkage between cysteine residues, which helps form an internal ring structure.
- inorganic sulfate.
Metabolic functions
- All body cells contain sulfur compounds; it's necessary for most organs & processes.
- Essential to production of insulin, the hormone secreted by the pancreas essential for carbohydrate metabolism.
- Necessary to formation of all but one of the glycosaminoglycans (GAGs): molecules of long, unbranched polysaccharides (mucopolysaccharides) containing a repeating disaccharide unit.
- The important GAGs are dermatan sulfate, chondroitin sulfate, heparin, heparan sul fate, keratan sulfate, and hyaluronic acid (the one with no sulfur).
- GAGs build proteoglycans (mucoproteins) from GAGs covalently attached to the core proteins; proteoglycans occur in all connective tissues, extracellular matrix and on the surfaces of many cell types.
- Langford (6/05) says GAGs "are lacking in the diet and should be supplemented."
- Key component of Glutathione.
- "In healthy conditions the liver converts dietary L-cysteine into glutathione, taurine, sulfate, cystine, and allows a tolerated amount of unconverted L-cysteine to circulate in blood for direct uptake by body cells and organs." from CFS Nutrition's Impaired Sulfur Oxidation
- "Sulfation is ... a primary and critical step in the metabolism of thyroid hormones, when D1 activity is normal" Metabolism of Iodothyronines.
- Excretion of water soluble metabolites of deconjugated hormones (estrogens and DHEA circulate almost entirely as sulfate esters) [Mentioned by Marilyn Bachmann on the Metals list, 31 Jul 2003. Need supporting references.What about progesterone?]
- Supports gallbladder
- Sulfate required to form the protective barrier mucin along the inner lining of the intestine
- Essential for collagen, and therefore for joint support, and to make keratin, for healthy hair and skin, and healing wounds.
- Methionine and cysteine necessary for protein building. Dietary deficiency will cause weight loss.
Sulfoxidation converts other forms of sulfur to useful sulfate
- Excessive levels of L-cysteine are controlled by the liver using the enzyme cysteine dioxygenase (CDO) to decompose the amino acid to non-toxic and rapidly excretable sulfate.
- In a student paper Cysteine (with strong disclaimers that it may contain errors), Haris Hamsakutty mentions that in this process, CDO is "coupled" to cytochrome P450. So far I haven't found out what this means or anything more about this.
- Poisonous sulfites [R-SO3] are converted to sulfates [R-SO4]
- Process uses sulfite oxidase (SO)
- requires molybdenum
Detoxification - two of the Liver Phase II pathways require sulfur:
For more Information
- My pages
- Elsewhere on the Web
- Homocysteine Redux vs MSM - this page has a simple diagram of major parts of sulfur metabolism
- Sulfur and Mercury
- Yahoo! Health Groups: Sulfur stories
- "A forum for people who have seen very positive or very negative responses to sulfur supplements of various sorts."
- This group focuses on examining individual experience scientifically, considering both published research and logical deduction from observation. Not a chat group.
- Run by DAN! think-tank researcher Susan Cowen Owens.
- Private email: If you have information to contribute on dysfunctional sulfur metabolism, but don't want to join the Yahoo! group, please
Last updated 2 December 2005
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