Biochemistry:
Figure: Human proinsulin and insulin biochemistry, Junqueira et al., 1986 Insulin is a protein consisting of 51 amino acids contained within two peptide chains. A chain with 21 amino acids and B chain with 30 amino acids with two disulfide bridges connected the A and B chains. Another disulfide bridge links positions 6 and 11 in the A chain. (DeMeytes,1994)
Insulin receptor:
For insulin to exert its biological effects, it must first bind to specific receptors on the cell surface of all insulin target tissues. The insulin receptor is a glycoprotein consisting of two α-subunits and two β-subunits linked by disulfide bonds. The α -subunit of the insulin receptor faces outwards and contains the insulin binding domain, whereas the β-subunit express insulin stimulated kinas activity directed towards its own tyrosine residues. The α -subunit is totally extracellular, whereas the β-subunit is a transmembrane protein (Caeatham & Khan, 1995). …show more content…
This binding causes autophosphorylation of certain tyrosine molecules which causes activation of several intracellular insulin receptor molecules such as insulin receptor substrates (IRS), phosphatidylinositol-3-kinase (PI-3k) and other mediating