Insulin Receptors are areas on the outer part of a cell that allow the cell to join or bind with insulin that is in the blood. When the cell and insulin bind together, the cell can take glucose (sugar) from the blood and use it for energy. Phe 25B is the active site of insulin. Insulin makes contact with the insulin receptor in a hydrophobic pocket.  This causes the C-terminus of the B chain to separate from the N-terminus of the A chain.  This allows for more binding and reactions to occur. Although insulin stimulates a vast array of responses in its target tissues skeletal muscle, adipose tissue and the liver, they all appear to be initiated by an interaction between insulin and a protein receptor located on the cell membranes of these tissues.  The insulin receptor protein can only be found on these tissues, which explains the specificity of the action.  When insulin binds it induces a conformational change within the receptor, known as oligomerization, which leads to autophosphorylation of specific tyrosine residues in the cytoplasmic domains of the receptors.
 
 
 

Insulin Receptor

To view the insulin receptor in cartoon form