Search results
Results from the WOW.Com Content Network
The binding of the exotoxin and antibody forms an antigen-antibody interaction and the exotoxins are targeted for destruction by the immune system. If this interaction does not happen, the exotoxins bind to the exotoxin receptors that are on the cell surface and causes death of the host cell by inhibiting protein synthesis. This figure also ...
Diphtheria toxin is a single polypeptide chain of 535 amino acids consisting of two subunits linked by disulfide bridges, known as an A-B toxin.Binding to the cell surface of the B subunit (the less stable of the two subunits) allows the A subunit (the more stable part of the protein) to penetrate the host cell.
This three-dimensional structure of the TSST-1 protein was determined by purifying the crystals of the protein. [1] The two domains are adjacent from each other and possess unique qualities. Domain A, the larger of the two domains, contains residues 1-17 and 90–194 in TSST-1 and consists of a long alpha (α) helix with residues 125-140 ...
Pertussis toxin is an exotoxin with six subunits (named S1 through S5—each complex contains two copies of S4). [12] [13] The subunits are arranged in A-B structure: the A component is enzymatically active and is formed from the S1 subunit, while the B component is the receptor-binding portion and is made up of subunits S2–S5. [13]
A toxoid is an inactivated toxin (usually an exotoxin) whose toxicity has been suppressed either by chemical or heat treatment, while other properties, typically immunogenicity, are maintained. [1] Toxins are secreted by bacteria, whereas toxoids are altered form of toxins; toxoids are not secreted by bacteria.
It is slightly unusual in that it combines the A and B parts in the same protein chain: the pre-toxin is cleaved into two parts, then the two parts are joined by a disulfide bond. [5] The exotoxin A of Pseudomonas aeruginosa is another example of an AB toxin that targets the eEF2. The "A" part is structually similar to the DT "A" part; the "B ...
SpeB was identified in 1919 as an ectoenzyme secreted by certain strains of streptococci. [11] It was originally studied as two separate toxins, streptococcal pyrogenic exotoxin B and streptococcal cysteine proteinase, until it was shown that both proteins were encoded by the speB gene and that the attributed pyrogenic activities were due to contamination by SpeA and SpeC.
When the pore is formed, the tight regulation of what can and cannot enter/leave a cell is disrupted. Ions and small molecules, such as amino acids and nucleotides within the cell, flow out, and water from the surrounding tissue enters. The loss of important small molecules to the cell can disrupt protein synthesis and other crucial cellular ...