Science
Mechanism of Action
Keratinases function as proteolytic enzymes that specifically cleave peptide bonds within insoluble keratin protein. Their primary target includes keratin filaments and corneodesmosomes, the structures that hold corneocytes together in the stratum corneum. This enzymatic breakdown temporarily increases the skin's permeability, thereby facilitating superior absorption of subsequently applied active ingredients and promoting efficient cell communication and regeneration. The complex degradation process involves three key stages: an initial denaturation reducing cystine disulfide bonds to cysteine thiols, followed by hydrolysis where the denatured keratin is broken down into smaller polypeptides, oligopeptides, and free amino acids, and concluding with transamination, which produces ammonia and sulfide.
Research
Clinical Evidence
Low confidenceN/A
Transparency
Dusting Analysis
The Formula
Formulation
Stability
Optimal enzymatic activity for most keratinases is observed between pH 7.0 and 10.0, with some varieties demonstrating activity from pH 5.5 up to 12.5. For stability, certain keratinases maintain approximately 90% activity for 16 hours at pH 7.0 and for 2 hours at pH 9.0, but are highly sensitive to more acidic pH levels. Optimal temperature ranges for activity typically fall between 28-50°C, though some variants exhibit stability and activity up to 70°C or even 100°C.
Conflicts
- Ethylenediaminetetraacetic acid (EDTA) can significantly inhibit keratinase activity, showing 90.4% inhibition at 1 mmol/L and 99.57% at 5 mmol/L.
- Phenylmethylsulphonyl fluoride (PMSF) can inhibit serine keratinases.
- Urea significantly inhibits keratinase activity, with reductions of 7.88% at 1 mmol/L and 3.17% at 5 mmol/L.
- Extreme acidic pH can lead to reduced stability and activity.
- High temperatures can result in enzyme denaturation.
Safety
Safety Profile
The Cosmetic Ingredient Review (CIR) Expert Panel has assessed 'Keratin and Keratin-Derived Ingredients' (such as Hydrolyzed Keratin) as safe; however, this specific evaluation does not extend to the enzyme 'Keratinase' itself.
Your Skin
Skin Compatibility
Our Assessment
Verdict
Keratinase is a valuable enzymatic ingredient, offering targeted exfoliation and enhanced ingredient penetration through its precise keratin-degrading mechanism, though further specific safety and clinical efficacy data for topical application are desired.
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