Insulins from different species--chicken and snake

We have worked out a new adsorption method for the preparation of insulins from different species. At present, we are mainly involved in chicken and snake insulins. In all insulins so far studied, only chicken insulin has been reported to have much higher activity. However, results from different laboratories are quite different from one another. We have obtained chicken insulin in typical rhombohedral crystalline form and determined its activity in vivo which is not appreciably different from that of porcine insulin. From the pancreas of a non-venomous snake, Zaocys dhumnades dhumnades (Cantor), we have prepared snake insulin which is different from rattle snake insulin reported earlier. The dodecahedral crystals of the snake insulin are similar to those of zinc-free porcine insulin.