A PROPOSED INTERACTION-MODEL OF THE INSULIN MOLECULE WITH ITS RECEPTOR

Based on the extensive structural comparisons among the determined str uctures of the different species and crystal forms of insulin and its derivatives in our laboratory, it was suggested that the binding inter action with the receptor molecule should take place mainly on an amphi pathic surface of the insulin molecule. In the middle of this amphipat his surface, there was a hydrophobic surface with an area of about 150 Angstrom(2), while the polar and charged groups distributing around t he hydrophobic surface constructed a hydrophilic zone. The hydrophobic surface was usually covered by the extended B-chain C-terminal peptid es with great mobility. The angle between the proposed binding interac tion surface and the surface of dimerization was about 20 degrees. The results from studies on structures of Al-(L-Trp) insulin and Al-(D-Tr p) insulin confirmed the interaction mechanism model we proposed.