AAT Bioquest

What are the differences between proteinase K and protease?

Posted May 19, 2023


Proteinase K and protease are two types of protein-cleaving enzymes. While both are capable of cleaving peptide bonds in proteins, they differ considerably in the way they work and their uses. 

Proteinase K 

Proteinase K is a broad-spectrum serine protease enzyme that acts mainly on keratin protein. It plays a key role in digestion of proteins and eliminating contamination from nucleic acid preparations. 


Protease is an enzyme catalyzing proteolysis. It acts mainly on the proteins in foods and plays a key role in multiple biological functions including cell signaling, digestion of ingested proteins, and protein catabolism. 

Additional resources

Characterizing Protease Specificity: How Many Substrates Do We Need?


Amplite® Universal Fluorimetric Protease Activity Assay Kit *Green Fluorescence*