Zinc found to be critical for preserving insulin production

Zinc may play a crucial role in preventing molecular reactions that lead to the destruction of insulin-producing beta cells and the development of type 2 diabetes, according to a new study from a team of University of Michigan researchers.

The investigators reported in the Journal of Molecular Biology that zinc binds to tiny molecules called amylin, which have a tendency to clump together. This process of accumulation produces toxic effects that kill off beta cells, decreasing insulin production and leading to unchecked blood sugar levels and type 2 diabetes.

Amylin molecules serve a dual purpose in the body. When zinc levels are normal, amylin helps keep glucose levels in check. A synthetic version is actually used alongside insulin therapies. However, its tendency to clump together makes it potentially dangerous. It can form dense buildups that shut down cells around it.

This is where zinc comes in. The researchers described the mineral in terms of a security guard at a rock concert. When the guard is present, people are able to calmly enjoy the show. However, when there is no guard, the crowd can form into gangs, get rowdy and shut everything down.

Zinc plays the role of the security guard. By bonding with amylin molecules, zinc prevents the compound from bonding with other amylin molecules. This discourages the clumping that damages beta cells and leads to type 2 diabetes. Furthermore, a single zinc molecule can bond with several units of amylin, so exceptionally high levels are not necessary for proper regulation of the process.

However, the team did note that when zinc levels do get too high it forms a self-defeating cycle. Zinc can bond to two different locations on amylin. It prefers linking to the middle. This puts a kink in the amylin and prevents the formation of clumps. However, when there is too much zinc and all of the middle amylin bonds are taken, surplus zinc units bond to end points on amylin, straightening them out and allowing them to again form clumps.

The present experiment was conducted in an artificial environment, and the researchers noted that human trials may deliver different results, particularly because the body's zinc levels are constantly fluctuating. However, they believe their findings could be useful in the development of new medications that keep beta cells functioning normally, which could prevent type 2 diabetes.