MCB 3020C Lecture Notes - Lecture 32: Shiga Toxin, Shigella Dysenteriae, Anthrax Toxin
Document Summary
Staphylococcal alpha toxin: a pore forming cytotoxin that is produced by growing staphylococcal cells (a cytolysin) Released as a monomer, 7 subunits oligomerize in cytoplasmic membrane forming a pore in target cell. Pore releases the contents of cell allowing the influx of extracellular material & efflux of intracellular material. Eukaryotic cells swell & lyse; in erythocytes, hemolysis. Made of 3 parts: each individual anthrax toxin protein is, in fact, nontoxic. A2b: b component called protective antigen (pa, a components: Pa(b) binds to anthrax receptor and then binds the ef & lf (endocytosis brings complex into cell) low ph of endosome causes conformation changes and allows ef & lf to enter cytosol and cause damage). Enzymatic activities lead to altered signaling pathways which cause macrophage functions to be impaired and ultimately apoptosis of the target cell. Pseudomonas aeruginosa: similar to diptheria toxin: adp ribosylation of ef2.
