A folding variant of α-lactalbumin with bactericidal activity against Streptococcus pneumoniae

Abstract

α-lactalbumin from human milk whey, but fluctuating tertiary structure. Native α-lactalbumin could be converted to the active bactericidal form by ion-exchange chromatography in the presence of a cofactor from human milk casein, characterized as a C18:1 fatty acid. Analysis of the antibacterial spectrum showed selectivity for streptococci; Gram-negative and other Gram-positive bacteria were resistant. The folding variant of α-lactalbumin is a new example of naturally occurring molecules with antimicrobial activity.