Mechanism of the Production of Diphtheria Toxin: The Role of Sulphur Compounds and of Copper and Iron

Abstract

In spite of the enormous amount of work that has been done to obtain a better knowledge of the biochemical process of the production of diphtheria toxin there are still many uncontrolled factors which need elucidation. The object of the present study was to determine what part certain sulphur linkages may play in the elaboration of diphtheria toxin and, in correlation with this, to ascertain what influence copper and iron may exert. From the bacteriologic point of view, these substances have attained a certain importance, because some of the sulphur compounds have been found to be essential among the food requirements of the diphtheria bacillus, and because copper has been assumed recently to be a constituent of the toxin molecule. From the biochemical point of view, sulphur compounds are of special interest, because some are intimately connected with the respiration of cells and oxidation-reduction phenomena, and play a prominent part in autooxidation processes. In all of these reaction changes copper and iron are well known to participate as catalyzing agents. One might expect, therefore, that in the presence of the substances mentioned similar influences come into force during the production of diphtheria toxin. Compared with some other phases of the same subject (the effect of carbohydrates and proteinic substances, and change in pn), relatively few references are available. These will be discussed later under the