Purification of recombinant HP-NAP expressed in
by DEAE resins at pH 7.0 to 9.0. Soluble fractions of E. coli expressing HP-NAP lysed at pH 9.0 were adjusted to the indicated pH ranging from 7.0 to 9.0 and a protein concentration of 0.3 mg/ml. These adjusted fractions, indicated as load, were then loaded onto DEAE Sephadex and DEAE Sepharose resins to purify recombinant HP-NAP by a batch method at 4°C as described in Methods. The unbound, wash, and elution fractions were analyzed by SDS-PAGE (A) and native-PAGE (B). Molecular weights (M) in kDa are indicated on the left of the stained gels. Similar results were obtained in at least two to four independent experiments.