Stratum corneum extracellular matrix and desquamation-related enzymes

The stratum corneum extracellular matrix and desquamation-related enzymes comprise a group of proteases and hydrolases essential for the terminal differentiation of the epidermis and the shedding of corneocytes (Egelrud, 2000). The primary enzymes involved are kallikrein-related peptidases, specifically KLK5 (stratum corneum tryptic enzyme), KLK7 (stratum corneum chymotryptic enzyme), and KLK14, along with cathepsins V, L, and D (Brattsand et al., 2005). These enzymes work in concert to degrade corneodesmosomes, the proteinaceous bridges containing desmoglein-1 and desmocollin-1 that maintain the integrity of the skin's outermost layer (Caubet et al., 2004). Proper regulation of this enzymatic activity is crucial for maintaining the skin barrier; for example, deficiency in the inhibitor LEKTI leads to the severe skin-shedding disorder Netherton syndrome due to KLK hyperactivation (Descargues et al., 2005). Conversely, reduced enzyme activity is a hallmark of xerosis and ichthyosis, where the skin becomes thickened and scaly. Pharmacological targeting of these enzymes often involves the use of keratolytics like salicylic acid or alpha-hydroxy acids, which modulate the local pH to optimize protease activity and facilitate desquamation (StatPearls, 2023).

Other names

Corneodesmosomal degradation enzymesStratum corneum proteasesDesquamatory enzymesSC enzymes

Keratolytic activity through pH modulation and direct disruption of corneodesmosomal bonds to facilitate desquamation.