Purification and properties of rabbit alveolar macrophage lysozyme

Lysozyme was isolated from Bacillus Calmette-Guerin-elicited rabbit alveolar macrophages by acid extraction and purified to homogeneity by a single-column procedure. Yields of the purified enzyme averaged between 20 and 30 mg per rabbit, values far in excess of those obtained with previously published methods. Rabbit lysozyme has a molecular weight of 14,300 and exhibits optimal lytic activity against Micrococcus lysodeikticus at an ionic strength of 0.04, pH 6.5. Our results indicate that lysozyme and other granule components can be fractionated from elicited alveolar macrophages by using simple techniques, suggesting methods for the bulk purification of lysosomal constituents.