Expression and purification of recombinant human annexin V in Escherichia coli

Human annexin V cDNA was cloned into plasmid pET19b and fused to a ten cons ecutive histidine tag at N-terminal. When expressed in E. coli BL21(DE3) Ly sS, the recombinant His10-annexin V accumulated in soluble form in the cyto plasm. By two-step chromatography, i.e., metal chelate affinity chromatogra phy and anion exchange chromatography, recombinant His10-annexin V was puri fied to homogenity on silver-stained SDS-PAGE gel. Recombinant annexin V, 7 .4 mg, was obtained from a 1 litre flask culture.