Crystallins are the predominant proteins of the eye lens which prevent the heat and oxidative-induced stress-induced aggregation of other proteins. They may be classified into two superfamilies, the α- and βγ- crystallins. The βγ- crystallins are long-lived structural proteins which refract light onto the retina. The microbial crystallins can not only bind to calcium ions, but even able to coordinate other ions such as Mg2+, Sr2+, Co2+, Mn2+, Ni2+, Zn2+ etc. Such metal ions may influence the stability and aggregation propensity of human γS- crystallin as well. Previous studies had even revealed the binding of αA- and αB- crystallins with Cu2+ ions and suppressed the formation of Cu2+ mediated oxygen species and thus protected ascorbic acid from oxidation by copper ions. The residues 71-88 present in mini αA- crystallin, a peptide of αA- crystallin were found to be responsible for the prevention of oxidation. The binding of metal ions to crystallins may influence the formation of protein aggregates, and thus cataract or other disorders but there are some ions which may even help to improve the chaperone activity of α crystallins. Adenosine triphosphate (ATP), the energy currency of the cell improves the chaperone activity of α-crystallins by regulating the chaperone-target substrate interactions. This minireview explores various insights of the interactions of crystallins with metal ions and ATP which may help in the search for more therapeutic molecules in near future.


Crystallins, Chaperone Activity, Interactions, Metal Ions, Protein Aggregates, Disorders, ATP, Therapeutic Molecules,


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