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. 2002 Dec 13;99(26):16684–16688. doi: 10.1073/pnas.262655299

Fig 7.

Fig 7.

Mass of PPK2 by size-exclusion chromatography. To measure the molecular mass of PPK2 complexed with poly P, the assay mixture (500 μl) contained 50 mM Tris⋅HCl (pH 8.0), 50 mM (NH4)2SO4, 5 mM MgCl2, 6 μg of PPK2 (Fraction 6 in table 1), and 2 mM poly P15 (Sigma). After incubation for 10 min at 37°C, 0.8 M KCl was added. The mixture was applied to a HiLoad 16/60 Superdex 200-pg column (Amersham Pharmacia) equilibrated with buffer PC [50 mM Tris⋅HCl, pH 8.0/0.5 mM EDTA/1 mM DTT/2 mM poly P15 (Sigma)/0.1% CHAPS] containing 0.8 M KCl. PPK2 was eluted with equilibration buffer and monitored by PNDK activity (diamonds). For measuring molecular mass of PPK2 without poly P, poly P was omitted from the incubation mixture and the equilibration (elution) buffer (circles). Positions of molecular mass standards are shown at the top of the panel: blue dextran (Vo), thyroglobulin (670 kDa), bovine gamma globulin (158 kDa), chicken ovalbumin (44 kDa), and equine myoglobin (17.5 kDa).