FIG. 2.

NanH purification demonstrated by SDS-polyacrylamide gel electrophoresis separation of proteins at various stages of the purification procedure. Samples were separated on an 8% gel and stained with Coomassie brilliant blue R-250. Approximately equal amounts of sialidase activity (units) were loaded into each lane. Lane 1, n-octyl glucoside (2%) extraction from whole cells; lane 2, ammonium sulfate precipitation (40 to 60%) of the detergent extraction; lane 3, CM-Sepharose sialidase-positive fraction, eluted with a NaCl gradient; lane 4, sialidase-positive fraction after separation on Sephacryl 200-HR; lane 5, DEAE Sepharose sialidase-positive fraction; lane 6, molecular weight markers (molecular weights are on the right, in thousands).