[A new bifunctional reagent for the intramolecular crosslinking of insulin (author's transl)]

Reaction of bis-[2-(succinimidooxycarbonyloxy)ethyl]sulfone [SO2(Eoc-ONSu)2] with insulin in 1N NaHCO3/dimethylformamide forms NalphaA1,NepsilonA1,NepsilonB29-2,2'-sulfonylbis(ethoxycarbonyl)insulin [SO2(Eoc)2-insulin] in 20 - 35% yield. The product can be purified by partition chromatography. After cleavage of the disulfide bridges, reoxidation in very dilute solution reconstitutes about 60% of the original insulin activity. Cleavage of the crosslinking moiety can be achieved with 0.5N NaOH at 0 degrees C in only a few seconds, rendering a biologically fully active insulin.