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Updated: Apr 2, 2026
10:08
Purification and Aggregation of the Amyloid Precursor Protein Intracellular Domain
Published on: August 28, 2012
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pH-Driven Distinct Aggregation Pathways of Human γD-Crystallin.
1School of Biotechnology, Jawaharlal Nehru University, New Delhi 110067, India.
The Journal of Physical Chemistry. B
|April 1, 2026
Summary
Human γD-Crystallin aggregation pathways differ significantly with pH. Acidic conditions promote amyloid fibril formation, while physiological pH leads to amorphous aggregates, offering insights into cataract mechanisms.
Area of Science:
- Biochemistry
- Structural Biology
- Ophthalmology
Background:
- Human γD-Crystallin is crucial for eye lens transparency.
- Protein aggregation, despite its stability, contributes to cataract formation.
Purpose of the Study:
- To investigate distinct aggregation pathways of human γD-Crystallin.
- To elucidate the influence of pH and temperature on aggregation.
- To provide mechanistic insights into γD-Crystallin-related cataracts.
Main Methods:
- Aggregation studies conducted at varying pH (2.0, 4.5, 7.4) and temperature (65 °C).
- Techniques included Thioflavin T (ThT) and Nile red fluorescence, transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF), circular dichroism (CD) spectroscopy, and 8-anilinonaphthalene-1-sulfonic acid (ANS) fluorescence.
Main Results:
- At pH 2.0 and 65 °C, amyloid fibrils with fragmentation were observed.
- At pH 4.5 and 65 °C, amyloid fibrils formed without fragmentation, indicating conformational changes.
- At physiological pH 7.4 and 65 °C, amorphous aggregates formed, lacking cross-β-sheet structure.
Conclusions:
- pH significantly dictates the aggregation pathway of human γD-Crystallin.
- Acidic pH promotes amyloid formation, while neutral pH leads to amorphous aggregates.
- These findings offer crucial mechanistic insights into cataractogenesis.
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