KNR50: a moonlighting bioactive peptide hidden in the C-terminus of bovine casein αS2 with powerful antimicrobial, antibiofilm, antiviral and immunomodulatory activities.

Milk is a primary nutrition source for newborns and adults and, in addition, is also a valuable reservoir of bioactive peptides. Many of these peptides are hidden as "cryptic" sequences in milk proteins and released in the bioactive form through protease digestions. Caseins, the most abundant proteins in bovine milk, host several cryptic bioactive peptides including those antimicrobials.