Filaggrin is a component of the cornified cell envelope and the precursor of free amino acids
acting as a natural moisturizing factor in the stratum corneum. Deimination is critical for the
degradation of filaggrin into free amino acids. In this study, we tried to identify the enzyme (s)
responsible for the cleavage of deiminated filaggrin in vitro. First, we investigated citrulline
aminopeptidase activity in the extract of newborn rat epidermis by double layer fluorescent
zymography and detected strong activity at neutral pH. Monitoring the citrulline-releasing …