This product was highly purified from growth media of the Corynebacterium diphtheriae mutant as mostly unnicked form.
CRM197 (Cross-Reacting Material 197) is a nontoxic mutant of Diphtheria toxin. CRM197, like wild-type Diphtheria toxin, is composed of a single polypeptide chain of 535 amino acids (58 kD) and nicked by cellular protease like furin to give fragments A (N-terminal, 21 kDa) and B (C-terminal, 37 kDa) which are linked by disulfide bridges. Binding to the cell surface of fragment B allows fragment A to penetrate the host cell. Fragment A of wild-type toxin catalyzes the ADP-ribosylation of eucaryotic elongation factor-2 (eEF2) by using NAD as a substrate, thus inactivating eEF2 and inhibiting protein synthesis. However, CRM197 has an alteration of 52nd Gly to Glu and has neither ADP ribosylation activity nor toxicity to cells. While CRM197 shows no enzymatic activity, it is immunologically indistinguishable from wild-type Diphteria toxin. CRM197 competitively inhibits binding of HB-EGF to HB-EGF receptor which is also Diphtheria toxin receptor.
1.0 mg/ml in 20 mM Tris-HCl (pH 7.2), 150 mM NaCl
More than 95% purity by SDS-PAGE
1) CRM197 retains activity to bind the receptor, HB-EGF (Heparin-Binding EGF-like Growth Factor) and inhibits the growth-stimulating activity of HB-EGF.
2) Putative drug for treatment of malignant tumors such as ovarian tumor, which secretes higher levels of HB-EGF.
3) Western blotting
Ship with dry-ice and store at -80°C.