Cloning and functional expression of the cytoplasmic form of rat aminopeptidase P

A rat cytoplasmic aminopeptidase P was purified from liver cytosol with a p rocedure including an affinity elution step with 3 mu M inositol 1,3,4-tris phosphate. Proteolytic fragments were generated, sequenced and the enzyme w as cloned from a rat liver cDNA library. The structure shows high (87.8% an d 95.5%, respectively) sequence identity at the nucleotide and amino acid l evels with the previously described human putative cytoplasmic aminopeptida se P. The cloned rat enzyme was functionally expressed in Escherichia coli and also in COS-1 cells. Western blot analysis, using an antibody generated against the recombinant protein, and Northern blot hybridization showed ub iquitous expression of the protein in different tissues with the highest ex pression level in the testis. (C) 1999 Elsevier Science B.V. All rights res erved.