ИСТИНА

Alpha-crystallin (CryA) is a structural protein in the vertebrate eye lens with chaperone-like activity. It exists in two isoforms: CryAA, predominantly found in the lens, and CryAB, expressed in various tissues, including the lens, heart, and brain. CryAB plays a vital role in maintaining cellular homeostasis by inhibiting the aggregation of misfolded proteins, thereby preserving lens transparency and preventing cataract formation. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), traditionally known for glycolysis, is recognised as a multifunctional enzyme. GAPDH is ubiquitously expressed in various cell types and is highly susceptible to oxidative stress, which can lead to its inactivation and aggregation. In the lens, oxidative stress is a major contributor to protein damage, including GAPDH oxidation, which may play a role in cataractogenesis. Notably, GAPDH activity is significantly reduced in aging and cataractous lenses. This study investigates the protective role of CryAB against oxidative stress-induced GAPDH damage. Our findings demonstrate that CryAB protects GAPDH from oxidative damage and denaturation. GAPDH incubation with H₂O₂ or guanidinium chloride in the presence of CryAB significantly preserves its enzymatic activity. CryAB prevents GAPDH oxidation and structural denaturation, maintaining its dehydrogenase activity under stress conditions. Furthermore, dynamic light scattering and enzyme-linked immunosorbent assay revealed that CryAB can encapsulate GAPDH. In conclusion, this study highlights the protective role of CryAB in safeguarding GAPDH from oxidative stress and denaturation. CryAB preserves the enzymatic activity of GAPDH, likely through a mechanism involving the encapsulation of GAPDH.