On electron microscopy amyloid characteristically exhibits:
Propeies of Amyloid Proteins: -Physical Nature of Amyloid: Electron microscopy-- Continuous, non-branching fibrils with a diameter of approximately 7.5 to 10 nm. X-ray crystallography and infrared spectroscopy-- Cross-b-pleated sheet conformation. This conformation is responsible for the distinctive Congo red staining and birefringence of amyloid. -Chemical Nature of Amyloid The AL (amyloid light chain)-excess of the light chains will deposit outside the cell in the form of Amyloid protein.It is seen in Multiple Myeloma patients. The AA (amyloid-associated) type of amyloid fibril protein is derived from unique non-Ig protein made by the liver. b-amyloid protein (Ab)-Seen in Alzheimer disease.(deposition of Ab plaque in the brain,causing damage to the coical neurons lowering the acetylcholine levels ,leading to |Memory.
B-plated sheets
Hyaline globules
7.5-10 nm fibrils
20-25 nm fibrils
Amyloidosis