Specific aminopeptidases of excised human nasal epithelium and primary culture: a comparison of functional characteristics and gene transcripts expression.

Objectives: To investigate whether growing human nasal epithelium as primary cultures alters aminopeptidase B (APB), aminopeptidase N (APN) and dipeptidyldipeptidase (DPPIV) metabolic characteristics, and mRNA gene transcript expression.

Methods: The formation of 7-amino-methyl coumarin from specific substrates for APN (L-alanine-4-methyl-coumaryl-7-amide, APB (L-arginine-4-methyl-coumaryl-7-amide) and DPPIV (glycyl-L-proline-4-methyl-coumaryl-7-amide) was used to estimate the KM, Vmax and the effect of aminopeptidases inhibitors on the enzymes. Polymerase chain reaction was used to investigate gene expression.