FIG. 1.

Effect of pneumococcal neuraminidase on sialylation of meningococcal LPS. Meningococcal strain N3 was grown up in chemically defined media with or without CMP-NANA (50 μg/ml). A total of 2.0 × 10⁸ CFU were then treated for 30 min at 37°C in C+Y medium with or without C. perfringens neuraminidase (neuramin.; 50 mU/ml) or supernatant (sup.) from 10⁸ CFU of the S. pneumoniae strain indicated (13, 17). The bacterial pellet was incubated with proteinase K at 65°C and then separated in Tricine-SDS-PAGE gels. LPS was visualized with a modified silver stain (A) or transferred to a nitrocellulose membrane and immunoblotted with MAb 3F11 (B).