Saturday, July 02, 2011

Zinc Prevents Type 2 Diabetes Damage

Zinc may help prevent type 2 diabetes damage by helping the protein amylin manage blood sugar levels, according to a new study published in the Journal of Molecular Biology.
 
Researchers at the University of Michigan said zinc prevents amylin—also known as Islet Amyloid Polypeptide (IAPP)—from forming harmful clumps similar to those found in Alzheimer's, Parkinson's, Huntington's and various other degenerative diseases. However, in a zinc-starved cellular environment of someone with type 2 diabetes, amylin clumps together with other amylin molecules, which leads to the formation of ribbon-like structures called fibrils that have been linked to a number of human diseases.

In a previous study, the research team showed when zinc binds to amylin, at a point near the middle of the amylin molecule, the amylin molecule kinks, which interferes with the formation of toxic clumps. In the current work, they show that the binding of zinc in the middle makes one end of the amylin molecule, called the N-terminus, become more orderly.

They found that the binding of zinc in the middle makes one end of the amylin molecule, called the N-terminus become more orderly. This is significant finding since the N-terminus is very important in clump formation and amylin toxicity.

The researchers also discovered that before amylin can begin forming fibrils, zinc must be coaxed from its nesting place. This happens because amylin has not one, but two binding sites for zinc. Zinc prefers to bind at the first site—the one in the middle of the amylin molecule, where its binding discourages fibril formation. When there's too much zinc around, all the binding sites in the middle positions are occupied and zinc must attach to amylin at the second site, which counteracts the effect of the first site. This may explain why decreased levels of insulin inside islet cells of diabetics result in islet cell death.

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