Team:ULaVerne Collab/Description
Diabetes mellitus is a metabolic disorder characterized by high glucose levels over a prolonged period of time and affects approximately 371 million people around the world (Castillo, 2012 & World Health Organization, 2014 ). Current treatments for diabetes include injections and pumps, but the cost to produce insulin has increased over the past few years due to monopoly companies and patent laws, making this life-saving medicine increasingly expensive to afford. Due to this, the goal of our project is to find a way to reduce the cost and improve production convenience of insulin. Therefore, we decided to focus on creating different single chain insulin analogues. Some of our novel insulin proteins are synthesized to be long-acting insulin and others are fast-acting insulin. Long-acting insulin keeps blood glucose levels under control in between meals and overnight and the short-acting insulin is injected after every meal (DrugBank, 2019).
To create these novel insulin proteins, it will require modifications in the A chain, B chain and different linker chains linking the A & B chains in order to change the isoelectric point. If the isoelectric point is closer to physiological pH (7.35-7.45), then the insulin protein is expected to be long lasting while if the pH is closer to the native insulin (5.4) then, our novel insulin protein is expected to be fast acting (Pirmoradian, 2016). Therefore, we based the changes of the A & B chains of our novel insulin proteins on the long-acting Glargine Insulin and the fast acting Lispro Insulin which are both manufactured already. The linker chains were created based on the Single- Chain Insulin as a Receptor Agonists research paper where different linker chain lengths were tested to find the optimal length at which the insulin functioned. In our first insulin analogue, we substituted the amino acid asparagine positioned at A21 to the amino acid alanine. These changes will decrease insulin solubility delaying its absorption thus prolonging its duration even after a meal creating the long-acting effect (Joshi, 2002). For our other insulin protein, we flipped the amino acids lysine and proline in the B chain obtained from Insulin Lispro for a fast-acting insulin protein. Once insulin is diffused, the hexamers of this molecule will dissociate from dimers to monomers allowing binding to the receptors for a faster reaction rate. The novel gene circuits of the modified insulins will be implementing combinations of a Histidine tag, Ecotin tag, TEV tag within the circuit in hopes of successfully secreting modified insulin proteins from Escherichia coli (E.coli). Moreover, the gene circuits of the modified insulin analogues will undergo a purification and characterization processes in the hope of making insulin more affordable and more effective for patients with diabetes.
