title: Peptidoglycan of Legionella pneumophila: apparent resistance to lysozyme hydrolysis correlates with a high degree of peptide cross-linking.
abstract: Peptidoglycan (PG) from Legionella pneumophila was composed of muramic acid, glucosamine, glutamic acid, alanine, and meso-diaminopimelic acid in a molar ratio of 0.8:0.8:1.1:1.7:1. Partially purified PG contained trypsin-insensitive proteins which were extracted by 1 N NaOH hydrolysis without apparent dissolution of the PG. Lysozyme hydrolysis of purified PG or cell walls caused an increase in reducing groups which correlated with roughly 70 to 100% digestion of disaccharides. However, there was no significant decrease in turbidity during lysozyme hydrolysis of purified PG or cell wall. Additionally, 80 to 90% of the meso-diaminopimelic acid epsilon-amino groups were not susceptible to dinitrophenylation. Collectively, the PG of L. pneumophila was sensitive to lysozyme hydrolysis and insensitive to alkali dissolution, and 80 to 90% of the NH2 groups of meso-diaminopimelic acid were apparently involved in cross-linkages between peptides.
mesh_terms: D000409:Alanine / Q000032:analysis; D002473:Cell Wall / Q000032:analysis; D055598:Chemical Phenomena; D002621:Chemistry; D005971:Glutamates / Q000032:analysis; D018698:Glutamic Acid; D006868:Hydrolysis; D007875:Legionella / Q000032:analysis*; D009113:Muramidase; D010457:Peptidoglycan / Q000032:analysis* / Q000302:isolation & purification / Q000378:metabolism; D012972:Sodium Hydroxide
chemical_list: D005971:Glutamates; D010457:Peptidoglycan; D018698:Glutamic Acid; D012972:Sodium Hydroxide; D009113:Muramidase; D000409:Alanine