1. Diabetes Revision of protein structure and the importance of genetic engineering in the control of diabetes

2. Some diabetes sufferers control their blood glucose levels by regular insulin injections. This means that they must test for blood glucose levels on a regular basis. The injection must be taken 30 mins before a meal twice daily.

4. Insulin is a hormone. It is made of protein and is involved in the regulation of glucose levels in the blood The primary sequence Notice amino acids are represented by three letters lower case.

5. The secondary structure. The alpha and beta chains chain contains helical forms. This is caused by hydrogen bonding between R groups on the amino acids.

6. The tertiary structure causes the formation of a monomer.

7. The quaternary structure involves the interaction of monomers to form hexamers.

8. Ribbon model of the hexamer unit

9. Insulin is injected as a hexamer as the monomers only exist at low concentrations making the volume to large to be injected

10. The insulin is released as a hexamer, which must be broken down to form monomers. Injected insulin is in the form of hexamers and it takes half an hour for the hexamers to form monomers and get into the blood stream. The dose contains two forms of insulin one a slow release and one a fast release form. Hexamers have to be injected as they exist in only very low concentrations. They naturally form hexamers at high concentrations. To inject the monomers at a low enough concentration at the right amount would involve too larger a volume

11. Can genetic engineering come the the rescue?

12. Producing insulin by genetic engineering

15. Modifying the amino acid sequence could stop the hexamers from forming by altering the intermolecular forces of attraction to prevent clumping Using computer modelling and computer graphics, it has been found that swapping the beta chain 9 th amino acid (ser) with asp stops the clumping

16. How can we change one residue?

20. Consideration of insulin has allowed us to revise structure of proteins and see how genetic engineering has been used to modify a protein to enhance its performance in a medical context.