Table 1.

Purification of a PIP2-dependent Arf GAP from bovine braina

StepProtein (mg)Specific activity (pmol/min/mg)Purification (fold)Recovery (%)
S2012,0000.421100
(NH4)2SO4 4,3000.781.968
DEAE4008.01964
HAP1205613423
HAP27.211828017
Phenyl-Sepharose1.15901,40413
Sephacryl 3000.359442,2466.7
Resource Q0.091,8754,4643.3
  • a GAP was purified as described in Materials and Methods. S20 is the soluble fraction from the 20,000 × g centrifugation of the crude brain homogenate. HAP1, hydroxylapatite column developed with a KPi gradient; HAP2, hydroxylapatite column developed with a KCl gradient. Activity was determined using 15 nM Arf1-GTP as substrate and 1 mg of crude phosphoinositide/ml as a source of phospholipid.