Countercurrent distribution of polysulfonated proteins (author's transl)]

The reaction of bovine beta-lactoglobulin AB with reagents 4-(isothiocyanato) benzene sulfonic acid, 5-(isothiocyanato) benzol-1,3-bis(sulfonic acid) and 7-(isothiocyanato) naphthalene-1,3,5-tris(sulfonic acid) is described. The blocking of the epsilon-amino groups of lysine is quantitative. The thus modified protein can be analysed in the countercurrent distribution apparatus and can be split very rapidly at the arginine residues with trypsin.