Keratinase is a type of enzyme that belongs to the family of proteases, which are specialized in breaking down keratin, a highly rigid structural protein found in hair, feathers, wool, and nails. Keratin is rich in disulfide bonds, making it extremely resistant to degradation by most proteolytic enzymes. This is where keratinase stands out due to its unique ability to hydrolyze these tough proteins into smaller, more manageable peptides and amino acids.