Deciphering Amyloid Fibril Formation through Protein Concentration by Optical Trapping.

ABSTRACT: Optical trapping, combined with time-lapse transmission and fluorescence imaging, enables precise real-time observation of protein concentration dynamics during amyloid fibril formation. Condensates form at the laser focus within 30 min and grow to ∼1.2 μm in diameter regardless of pD by optical trapping of apoferritin (Fer8). Initial trapping efficiency is higher at pD 8.4 (stable 24-mer) than under acidic conditions (pD 1.5 and 2.0; subunit dimer), while acidic solutions show a pronounced second-phase concentration increase after ∼72 min, ultimately far exceeding the concentration in pD 8.4. However, the second-phase surge is absent at pD 3.0, despite evidence of amyloid formation (ThT fluorescence and transmission electron microscopy (TEM)), likely due to slower elongation presumably ow

SUBMITTER: Sugiyama T 

PROVIDER: S-EPMC12569677 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature