IMMUNOGLOBULIN CLEAVAGE BY HYPOCHLOROUS ACID TREATMENT

IgA, IgG and IgM were cleaved by hypochlorous acid treatment. The appa rent calculated molecular masses of three polypeptides obtained from I gA were 81.1. 25.8 and 13.9 kDa. The amounts of released IgA fragments were proportional to the amount of HOCl employed. At a HOCl:IgA molar ratio above 320:1, a profound degradation of IgA polypeptide chains o ccurred, resulting in a yellow-coloured product. The HOCl treatment of IgG resulted in similar effects, the liberation of three fragments, o ne of them being of a size slightly larger than that of the light chai n (30.4 kDa). The treatment of IgM with HOCl also produced three fragm ents: one corresponding to the monomeric IgM molecule, the second to t he light chain (26.4 kDa) and the third of a size smaller than the hea vy chain. The optimal protein/HOCl ratios for the degradation of IgG a nd IgM were 375:1 and 808:1, respectively.