Leucyl/Cystinyl Aminopeptidase (LNPEP)

LNPEP encodes a zinc-dependent aminopeptidase that cleaves vasopressin, oxytocin, lys-bradykinin, met-enkephalin, dynorphin A and other peptide hormones. The protein can be secreted in maternal serum, reside in intracellular vesicles with the insulin-responsive glucose transporter GLUT4, or form a type II integral membrane glycoprotein. The protein catalyzes the final step in the conversion of angiotensinogen to angiotensin IV (AT4) and is also a receptor for AT4. Alternative splicing results in multiple transcript variants encoding different isoforms.

The deduced 944-amino acid polypeptide contains the HEXXH consensus sequence of zinc metallopeptidases as well as an N-terminal hydrophobic region that resembles a transmembrane domain.