Israeli scientists say they have solid evidence that the precursor molecules called protofibrils are the problem molecules in type II diabetes, and their results support a similar mechanism for Alzheimer's and Parkinson's. Further, they say that the current focus on breaking up the abnormal clumps of protein called fibrils may in fact be doing more harm than good.
The report appeared in the Sept. 23 edition of Biochemistry, a peer-reviewed journal of the American Chemical Society, the world's largest scientific society.
Proteins are the chemical workhorses of the body. These long chains of amino acids fold into myriad forms, but they must assume the right three-dimensional structure to function properly. Misfolded proteins are the basis of a number of seemingly unconnected diseases, including age-related diseases like type II diabetes, Alzheimer's and Parkinson's, as well as "mad cow" (BSE) and other prion diseases.
Despite many years of investigation, the actual mechanism of misfolding has eluded researchers, leaving them without the understanding necessary to develop effective treatments or even properly diagnose the diseases.
The most popular theory has revolved around long clumps of misfolded proteins known as amyloid fibrils that kill cells in patients. Therapeutic efforts have focused on breaking up these deposits. In Alzheimer's they are called amyloid plaques; in Parkinson's they are called Lewy bodies; in type II diabetes they are called islet amyloid deposits and occur in the "islets of Langerhans," the area of the pancreas where insulin is produced and regulated.
"Type II diabetes is one of the most common amyloid-related diseases," says Ehud Gazit, Ph.D., a researcher at Tel Aviv Univers
Contact: Michael Bernstein
American Chemical Society