Structure-activity relationships in diphtheria toxin.

  title={Structure-activity relationships in diphtheria toxin.},
  author={D. M. Gill and Alwin M. Pappenheimer},
  journal={The Journal of biological chemistry},
  volume={246 5},
The intact diphtheria toxin molecule, a single polypeptide chain of about 62,000 daltons, has no enzymic activity. However, the transfer in uifro of ADP-ribose from NAD to aminoacyltrensferase II can be catalyzed by any of several fragments of toxin. The smallest active fragment (A, 24,000 daltons) is normally connected to the remainder of the molecule (B, 38,000 daltons) by a peptide bond and a disull?de bond. Both of these bonds must be broken to activate Fragment A. Thus, for example, toxin… CONTINUE READING