Relationship between hemagglutinin and sialidase from Clostridium perfringens CN3870: chromatographic characterization of the biologically active proteins

Biochemical characterization of hemagglutinin and sialidase activities from C. perfringens strain CN3870 revealed that this strain produced three sialidase enzymes that were separable by gel filtration, ion exchange chromatography, and polyacrylamide gel electrophoresis. The molecular weights of sialidase I, II, and III activities were 310,000 ± 12,000, 105,000 ± 4,000, and 64,000 ± 2,000, respectively, the first figure being an approximate value only. Sialidase I and II activities were associated with hemagglutinin I and II activities, respectively. The separation methods used here failed to separate sialidase I activity from hemagglutinin I activity or sialidase II activity from hemagglutinin II activity. These results suggest that, for both the I and II forms, hemagglutinin and sialidase activities are associated in a protein complex. It was not certain if sialidase III activity was also associated with hemagglutinin activity. The results suggest that sialidase III was not a monomeric subunit of either the sialidase I or II enzymes.