Diphtheria toxin cystamine

Using this approach, EGF has been successfully conjugated by disulfide exchange to the A chain of diphtheria toxin (Shimisu et al., 1980). A cystaminyl derivative of insulin also could be conjugated to the A chain of diphtheria toxin by this method (Miskimins and Shimizu, 1979). Other references to disulfide exchange using cystamine include Oeltmann and Forbes (1981) and Bacha et al. (1983) who prepared antibody-toxin and peptide-toxin conjugates, respectively. 

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