PTP1B: Structure and Function in Relation to Type Two Diabetes

Insulin receptors send signals to the cell allowing glucose to enter. When all the glucose has entered the cell, an enzyme called PTP1B binds to the insulin receptors and dephosphorylates them, stopping the reaction. Some type two diabetics have broken insulin receptors, so not all the glucose has entered the cell when PTP1B dephosphorylates the insulin receptor. In this study, PTP1B was used to target type two diabetes treatments through the use of inhibitors. It was hypothesized that if a unique allosteric site on PTP1B could be identified, then it could help protein specific inhibitor development. To achieve this goal, a combination of computational and biochemical techniques were used. First, Molecular Dynamics Simulations were used to mutate PTP1B. Then, E. coli was grown with the mutated PTP1B. Next, the protein was purified using nickel beads, washes, and an Akta. From here, a Bradford Assay was done to determine the concentration of the mutants. Along with this, the time course measurements provided the catalytic range of the mutants. Data was provided for Wild Type, C215S, and S190A proteins. C215S was used as a control. The Madan Lab is in the process of standardizing more assays to expand this to other mutant proteins. Overall out of the eight mutations, S190A and F191A had the most activity confirming that the allosteric and active site communicate to one another. These findings have advanced research for type two diabetes treatments as hypothesized.