What are amyloid fibrils?

amyloid fibrils are protein -like protein engines that are insoluble and resistant to protease activity. Depending on the protein forming fibrils, amyloid structures may accumulate in different places in the body, including brain, joints and pancreas. Extensive genetic, pathological and biochemical evidence shows that the accumulation of amyloid fibrils in tissues is involved in many diseases, including Alzheimer's disease, Parkinson, type 2 diabetes and prion disease. For example, the brains of Alzheimer's patients show lords of amyloid fibrils made of beta-amyloid protein.

approximately 30 proteins form amyloid fibrils in humans; They are not relatives and do not share a common structure or sequential similarity. However, all of them are composed in a way that differs from normal protein folding formulas, with the same structure always found in the core of fibrile. Proteins that create amyloid fibrils in human diseases include immunoglobulin light chains, gelsolin, procalcitonin, beta-amylid protein, amyloid and amyloid protein, serum, beta 2-classhoglobulin, transtyretin and prion protein.

Regardless of the proteins involved, amyloid fibrils have characteristic structural properties, in particular their Quaternary structure between beta. Individual proteins are built in long fibers that connect side by side to the ribbons. These piles of beta-lists, firmly connected by hydrogen bonds, run perpendicular to the long fibrile axis.

This distinctive structure could arise from a strong charge carried by building blocks fibrils. Proteins with glutamine -rich sequences are important in prion diseases and Huntington's disease. Glutamins can cheat on the structure of beta-listins by creating intraastrage hydrogen bonds between amide carbonyls and nitrogens. In other proteins such as Alzheimer's beta-amelooid protein associated with Alzheimer's disease, hydrofIt is assumed that it is assumed that the structure is held together.

amyloid fibrils are the result of problems in protein self -self -made and seems to be the result of the aging process. The vast majority of diseases caused by amyloid structures are found in older patients. Once it was believed that the ameloid fibrils were inert, with toxic intermediates to damage the cells during their formation causing cell damage. However, the research has shown that the fibers themselves are actually toxic, especially if they are fragmented in shorter pieces. It is not exactly known how toxic fibers are toxic to the cells or why shorter fibers are more toxic, but one option is that their small size makes it easier to enter cells.

These fibrils have a characteristic straight, non -saying appearance when observed by electron microscopy. They are usually identified indirectly using fluorescent dyes, polarimetry stains, circular dichroism or Fourier transformation infrared spectroscopy. X -rayDiffraction analysis may be used to direct the presence of the structure of the cross spine according to the characteristic scattering diffraction signals.