FIGURE 6. Heparin binds to pCAF HAT enzyme.

pCAF HAT enzyme was incubated with heparin-Sepharose or Sepharose resin in the presence of increasing sodium chloride concentrations for 1 hour at 4°C. Following centrifugation at 10,000g for 10 minutes, the supernatants were assayed for enzymatic activity. Supernatant aliquots (20μl) were assayed for HAT activity in the presence of 10μg (~10 μM) core histones and [³H]acetyl CoA (0.5μCi; 50 μM) for 30 minutes at 30°C prior to vacuum filtration onto a nitrocellulose membrane. The sample wells and filter were washed with 50mM tris pH 7.6 and the membrane was processed for liquid scintillation counting. The data are expressed as percent relative pCAF HAT activity (pCAF HAT activity recovered after incubation with heparin-Sepharose/pCAF HAT activity recovered after incubation with Sepharose) × 100. The data presented are mean % Control ±SD. Similar results were observed in three separate experiments.