Cell: the first detailed analysis of β - amyloid fiber structure

Studies have shown that Alzheimer's disease is caused by the accumulation of abnormal threadlike protein deposits in the brain, but little is known about the molecular structure of these so-called β - amyloid fibers Recently, a team of researchers from NIH, the National Institutes of health, published a new result, which revealed that different molecular structures of β - amyloid fibers may be determined by different clinical histories and different degrees of brain damage in patients with Alzheimer's disease This discovery will help to develop new treatment methods and improve the diagnosis and treatment of this common disease The corresponding author of this paper is Robert, National Institutes of health Tycko, he said, "for the first time, this work has detailed the molecular structure of β - amyloid fiber, which is a key protein leading to Alzheimer's disease." relevant detailed structural models can be used to guide the development of compounds that can bind to the protein with high specificity, for diagnostic imaging, and also for the development of drugs that inhibit protein formation , prevention and treatment of Alzheimer's disease " Alzheimer's disease (AD) is a chronic neurodegenerative disease worldwide, which mainly occurs in the middle-aged and the elderly With the aging of population, the incidence of ad is increasing Amyloid deposition is a well-known feature of this degenerative disease of the central nervous system characterized by progressive cognitive impairment Tycko and his team have previously found that β - amyloid fibers grown in Petri dishes have different molecular structures, which depend on specific growth conditions Based on this observation, they suggest that the fibrin found in the brain of Alzheimer's patients may also be variable, and these structural changes may be related to each patient's clinical history But for a long time, researchers have been unable to directly study the structure of the protein in the brain with low protein abundance To overcome this problem, tycko and his colleagues developed a new experimental scheme - they extracted β - amyloid fiber fragments from the brain tissues of two patients with different clinical histories and brain injury degrees, and then used these fragments to cultivate a large number of fibers in a culture dish Results the researchers found that each patient's brain tissue had a high amount of single fiber, and these molecular structures were different between patients "This may mean that the proteins that appear to be in a single position in the brain in the patient may be dispersed to other positions and maintain the same molecular structure," tycko said "Our study also shows that some protein fiber structures are more likely to cause Alzheimer's disease than other structures, which shows the importance of developing imaging reagents With these reagents, we can target special fiber structures and improve the reliability and specificity of diagnosis "