CRM197

CRM197 is a non-toxic mutant of diphtheria toxin that contains a single amino acid substitution (G52E) at position 52, where glutamic acid replaces glycine. This mutation causes the loss of ADP-ribosyltransferase activity of the native toxin, making it non-toxic while retaining its immunological properties. CRM197 is widely used as a carrier protein for polysaccharides and haptens to make them immunogenic, particularly in conjugate vaccines against encapsulated bacteria such as Streptococcus pneumoniae, Haemophilus influenzae type b, and Neisseria meningitidis. It is a single polypeptide chain of 535 amino acids (58.4 kDa) consisting of two subunits linked by disulfide bridges. Beyond its use in vaccines, CRM197 has shown potential anticancer activity by binding to heparin-binding epidermal growth factor (HB-EGF), which is often overexpressed in cancer cells.

Brand names

prevnar 20prevnar20prevnar-20vaxneuvance

Other names

Cross Reacting Material 197