Fig. 2. Purification of PCBP-25 and CaM on MonoQ (A) and chromatographic separation of PCBP-25 and PCBP-25ß visualized by silver stain (B). Chromatography was performed as described in the Materials and Methods. In A, the fractions containing PCBP-25 determined by on-blot ⁴⁵Ca²⁺-binding assay are indicated, as are the positions of two CaPKs and CaM. In (B), MonoQ fractions (15 µl each) were run on SDS-PAGE and silver stained as described in the Materials and Methods. The positions of Ca²⁺-binding proteins and the fraction numbers are indicated. M, M_r of markers (x10³).