αA- and αB- crystallins are the two principal components of the α-crystallin family of heat shock proteins which exhibit chaperone activity as well as cyto-protective function. It is well known that α-crystallin binds to misfolded or unfolded proteins and prevents their aggregation. The interactions of various proteins, such as methionine sulfoxide reductase A (MsrA), galectin-related interfiber protein (GRIFIN), histones and creatine kinase enzymes with α- crystallin may be deduced from their changes in abundance in the cell. The alterations in the abundance of histone proteins with a loss of normal chaperone function of α-crystallin suggest their importance in the biochemical mechanisms of hereditary cataract formation. Various proteomic and mass spectrometric methods have been utilised to elucidate the relationships between ɑ-crystallin chaperone function, substrate binding and retinal disorders such as hereditary cataract, retinal neurodegenerative diseases and other systemic disorders and inflammation. A special emphasis on such interactions and in vivo protective roles of α-crystallin, under normal and pathological conditions, may highlight the potential of crystallins as therapeutic agents.
Key words: ɑ-crystallin, misfolded protein aggregation, protein interactions, chaperone, systemic disorder