Members of the subtilisin-like proprotein convertase family process latent precursor proteins into their biologically active products. PCSK1N functions as an inhibitor of prohormone convertase 1, which regulates the proteolytic cleavage of neuroendocrine peptide precursors. Recombinant human PCSK1N protein, fused to His-tag at N-terminus, was expressed in E.coli .