An enzyme that primarily degrades this protein forces substrates to refold into beta-sheets in a triangular prism-shaped active site. Two disulfide bonds stabilize the two chains of this protein, which originate from cleavage of a single precursor that assembles into hexameric complexes that coordinate to zinc. (10[1])This protein propagates signals after binding a receptor tyrosine kinase that triggers the PI3K and ERK pathways. Intracellular vesicles sensitive to this protein express the protein GLUT4. Amylin and this hormone are produced in the islets of Langerhans in beta cells of the pancreas. This hormone promotes the formation of glycogen. For 10 points, name this peptide hormone that promotes absorption of glucose (10[1])that is deficient in diabetes. ■END■ (10[1])