Pertussis toxin they are formed from two subunits. The "A" subunit possesses enzyme activity, and is transferred to the host cell following a conformational change in the membrane-bound transport "B" subunit. Pertussis toxin is an exotoxin with six subunits (named "S1" through "S5"—each complex contains two copies of "S4"). 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. The subunits are encoded by "ptx" genes encoded on a large PT operon that also includes additional genes
Ménétrier's disease Ménétrier's disease Ménétrier disease (also known as hypoproteinemic hypertrophic gastropathy; named after a French physician Pierre Eugène Ménétrier, 1859–1935), is a rare, acquired, premalignant disease of the stomach characterized by massive gastric folds, excessive mucous production with resultant protein loss, and little or no acid production. The disorder is associated with excessive secretion of transforming growth factor alpha (TGF-α). Individuals with the disease present with upper abdominal pain (epigastric), at times accompanied by nausea, vomiting, loss of appetite, edema, weakness, and weight loss. A small amount of gastrointestinal bleeding may occur, which is typically due to superficial mucosal erosions; large