In International journal of biological macromolecules
Proteolysis of amyloids is related to prevention and treatment of amyloidosis. What if the conditions for proteolysis were the same to those for amyloid formation? For example, pepsin, a gastric protease is activated in an acidic environment, which, interestingly, is also a condition that induces the amyloid formation. Here, we investigate the competition reactions between proteolysis and synthesis of amyloid under pepsin-activated conditions. The changes in the quantities and nanomechanical properties of amyloids after pepsin treatment were examined by fluorescence assay, circular dichroism and atomic force microscopy. We found that, in the case of pepsin-resistant amyloid, a secondary reaction can be accelerated, thereby proliferating amyloids. Moreover, after this reaction, the amyloid became 32.4 % thicker and 24.2 % stiffer than the original one. Our results suggest a new insight into the proteolysis-driven proliferation and rigidification of pepsin-resistant amyloids.
Cheong Da Yeon, Roh Seokbeom, Park Insu, Lin Yuxi, Lee Young-Ho, Lee Taeha, Lee Sang Won, Lee Dongtak, Jung Hyo Gi, Kim Hyunji, Lee Wonseok, Yoon Dae Sung, Hong Yoochan, Lee Gyudo
2022-Dec-18
Amyloid proliferation, Amyloid stiffening, Atomic force microscopy, Pepsin, Proteolysis of amyloid
