Human lipocortin (annexin) 1, a member of the annexin family of phosph
olipid binding proteins, has previously been expressed in E. coil (Huh
et al., 1990). To improve the expression level of lipocortin 1 in E.
coli, several expression vectors containing either the P-L or the P-tr
c promoter were constructed. The highest expression level, up to 20% o
f the total E. coli proteins, was obtained with plasmid pHT3. Plasmid
pHT3 contains the pUC origin, the lipocortin 1 cDNA under P-trc promot
er, and the lacI gene.