Figure 6.

Effects of centrifugation and membrane filtration on the activity in spleen homogenates. (A) The spleen homogenate (H) was separated into supernatant (S) and particulate (P) fractions with centrifugation at 100,000 × g. The supernatant fraction (S) was also subjected to membrane filtration by using an Amicon 10 membrane that retains 10,000-Da molecules. The retained material (R) and filtered material (F) were also examined for activity to denitrate the nitrated BSA (N-B). Incubated samples were examined for nitrated BSA with Western immunoblots. (B) Coomassie brilliant blue staining of a transferred membrane from the experiment in A. (C) Total enzyme activity in each of the fractions from eight different spleen homogenates was determined with appropriate dilutions. Columns and bars represent mean ± SD.