Figure 1.

Expression and purification of AAPP truncated forms and Ca²⁺ binding assay. (A) Schematic representation of AAPP truncated forms. The AAPP gene is encoded by four exons. A series of truncated rAAPPs according to the exon arrangement were produced in E. coli expression system. The GE-rich region and collagen binding domain are shown. (B) SDS-PAGE analyses of AAPP truncated forms. (C) Comparative staining of acidic proteins with Stains-All of AAPP truncated forms. (D) Calcium binding assay of AAPP truncated form on nitrocellulose membrane after SDS electrophoresis with the reference of calmodulin. Protein bands are shown after autoradiography.