Kallikrein 5

Kallikrein-5, formerly known as stratum corneum tryptic enzyme, is a serine protease expressed in the epidermis. In humans, it is encoded by the KLK5 gene . This gene is one of the fifteen members of the kallikrein subfamily located in a cluster on chromosome 19.

The protein kallikrein-5 (with a molecular weight of ~40.0 kDa) is likely involved in epidermal desquamation, suggesting a role in the process of skin shedding and exfoliation. Its association with desquamation suggests that it plays a role in the removal of corneocytes on the skin surface, which is critical for skin homeostasis. Kallikrein-5 Protein, Human (HEK293, His) is the recombinant human kallikrein-5 protein with C-6*His-tag expressed from HEK293.

All members of the KLK family exhibit trypsin or chymotrypsin-like activities. Most of them are localized in certain cells of human skin, with KLK5, KLK7 and KLK14 being three prominent members involved in epidermal desquamation. In situ hybridization methods confirmed the expression of KLK1 mRNA in eccrine sweat glands (Komatsu N et al. 2003) and found that its expression is much broader, extending to the stratum granulosum of the normal epidermis and to the inner root sheath of the hair follicle epithelium (Komatsu N et al. 2003).

It is noteworthy that the activity of kallikrein-5 is inhibited by ^Zn2+, indicating a possible regulatory mechanism for its enzymatic function. Further research into the functions of kallikrein-5 could deepen the understanding of its role in skin biology and its potential effects in various physiological contexts.

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