title: Role of autolysin in generating the pneumococcal purpura-producing principle.
abstract: The results of four studies described in this paper support the idea that pneumococcal autolysin (N-acetylmuramyl-L-alanine amidase) plays a key role in generating the pneumococcal purpura-producing principle (PPP) from the bacterial cell wall. This conclusion is based on the observation that (i) concentrates of pneumococcal cell-free extracts prepared at a pH which is inhibitory to autolysin activity contained significantly less PPP activity than extract concentrates prepared at a pH which is optimal for autolysin activity; (ii) PPP activity was not detectable in concentrates of cell-free extracts prepared from cells which contained ethanolamine in the cell wall, but a normal amount of activity was found in extract concentrates derived from cells containing choline in the cell wall; (iii) PPP activity was not detectable in concentrates of cell-free extracts prepared from an autolysin-defective mutant, but a normal amount of activity was found in extract concentrates derived from the wild-type strains; and (iv) incubation of purified wild-type strain cell walls with pneumococcal autolysin resulted in a significant increase in the amount of purpurogenic activity in the supernatant fluids of the incubation mixtures.
mesh_terms: D000581:Amidohydrolases / Q000378:metabolism*; D002473:Cell Wall / Q000378:metabolism; D002794:Choline / Q000502:physiology; D004983:Ethanolamines / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000378:metabolism*; D010457:Peptidoglycan / Q000378:metabolism*; D011693:Purpura / Q000209:etiology*; D013296:Streptococcus pneumoniae / Q000378:metabolism*
chemical_list: D004983:Ethanolamines; D010457:Peptidoglycan; C029323:pneumococcal purpura-producing principle; D000581:Amidohydrolases; D009238:N-Acetylmuramoyl-L-alanine Amidase; D002794:Choline