Search results
Results from the WOW.Com Content Network
From the sulfide they form the amino acids cysteine and methionine, sulfolipids, and other sulfur compounds. Animals obtain sulfur from cysteine and methionine in the protein that they consume. Sulfur is the third most abundant mineral element in the body. [21] The amino acids cysteine and methionine are used by the body to make glutathione.
The thioredoxin dependent adenylyl-sulfate reductase's cleaved disulfuric ions are incorporated into the molecular structure of the proto-proteins in the formation of the aforementioned amino acids. In studies such as one published in the Journal of Biological Chemistry experimentally observed the use of this enzyme type and thioredoxin in the ...
Furthermore, the reduced sulfur is incorporated into cysteine, [2] an amino acid that is a precursor to many other sulfur-containing compounds. In animals, sulfur assimilation occurs primarily through the diet, as animals cannot produce sulfur-containing compounds directly.
Nature is abound with organosulfur compounds—sulfur is vital for life. Of the 20 common amino acids, two (cysteine and methionine) are organosulfur compounds, and the antibiotics penicillin and sulfa drugs both contain sulfur. While sulfur-containing antibiotics save many lives, sulfur mustard is a deadly chemical warfare agent.
Bacteria contain cysteine desulfurases to form iron sulfur clusters in proteins. [2] However recently it has been shown that the enzyme, which produces hydrogen sulfide from cysteine, is also a virulence factor, namely for M.pneumoniae, in that it causes both α-hemolysis and β-haemolysis of red blood cells. [1]
CBS occupies a pivotal position in mammalian sulfur metabolism at the homocysteine junction where the decision to conserve methionine or to convert it to cysteine via the transsulfuration pathway, is made. Moreover, the transsulfuration pathway is the only pathway capable of removing sulfur-containing amino acids under conditions of excess. [9]
Sulfur oxidation involves the oxidation of reduced sulfur compounds (such as sulfide H 2 S), inorganic sulfur (S), and thiosulfate (S 2 O 2− 3) to form sulfuric acid (H 2 SO 4). A classic example of a sulfur-oxidizing bacterium is Beggiatoa, a microbe originally described by Sergei Winogradsky, one of the founders of environmental microbiology.
Giant tube worms use bacteria in their trophosome to fix carbon dioxide (using hydrogen sulfide as their energy source) and produce sugars and amino acids. [5] Some reactions produce sulfur: hydrogen sulfide chemosynthesis: [1] 18H 2 S + 6CO 2 + 3 O 2 → C 6 H 12 O 6 (carbohydrate) + 12H 2 O + 18 S