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The structure of a disulfide bond can be described by its χ ss dihedral angle between the C β −S γ −S γ −C β atoms, which is usually close to ±90°. The disulfide bond stabilizes the folded form of a protein in several ways: It holds two portions of the protein together, biasing the protein towards the folded topology.
In industrial and environmental chemistry, an organophosphorus compound need contain only an organic substituent, but need not have a direct phosphorus-carbon (P-C) bond. [citation needed] Thus a large proportion of pesticides (e.g., malathion), are often included in this class of compounds.
Although the first phosphorus compounds observed to act as cholinesterase inhibitors were organophosphates, [90] the vast majority of nerve agents are instead phosphonates containing a P-C bond. Only a handful of organophosphate nerve agents were developed between the 1930s and 1960s, including diisopropylfluorophosphate , VG and NPF .
Since orthophosphoric acid has three −OH groups, it can esterify with one, two, or three alcohol molecules to form a mono-, di-, or triester. See the general structure image of an ortho- (or mono-) phosphate ester below on the left, where any of the R groups can be a hydrogen or an organic radical. Di- and tripoly- (or tri-) phosphate esters ...
By transferring the disulfide bond between these two cysteine residues onto the folding protein it is responsible for the latter's oxidation. In contrast to bacteria, where the oxidative and isomerization pathways are carried out by different proteins, PDI is also responsible for the reduction and isomerization of the disulfide bonds.
The dithiophosphine ylides are normally attacked at the phosphorus atom by a nucleophile, for instance the reaction of an alkoxide, phenolate, alcohol or phenol with a 1,3,2,4-dithiadiphosphetane 2,4-disulfide can form a new compound with a phosphorus-oxygen bond.
TCEP is often used as a reducing agent to break disulfide bonds within and between proteins as a preparatory step for gel electrophoresis.. Compared to the other two most common agents used for this purpose (dithiothreitol and β-mercaptoethanol), TCEP has the advantages of being odorless, a more powerful reducing agent, an irreversible reducing agent (in the sense that TCEP does not ...
6 These form water-stable salts. [12] The anion has an ethane-like structure and contains a P−P bond. The formal oxidation state of phosphorus is +4. The oxygen analogue is the hypodiphosphate anion, P 2 O 4− 6. P 3 S 3− 9 contains a six-membered P 3 S 3 ring. The ammonium salt is produced by reaction of P 4 S 10 in liquid ammonia. [13]