α‐Crystallin does not require temperature activation for its chaperone‐like activity

α‐crystallin acts as a molecular chaperone by preventing the aggregation of proteins. Although the mechanism for this activity is not understood there is a proposition that temperature activation at or above 30°C of α‐crystallin is an absolute requirement, thereby suggesting a conformational transition as a trigger for the activity. In an attempt to unravel the putative temperature‐activity relationship, the chaperone‐like activity of α‐crystallin was studied at a number of temperatures above and below 30°C. Chaperone activity was monitored against aggregation of the insulin‐B chain induced by cleavage of disulfide bond of insulin and also against photo‐aggregation of γ‐crystallin. Contrary to the above notion, the results indicate that α‐crystallin does not require thermal activation for its chaperone function and that it can efficiently function as a molecular chaperone even at temperatures below the previously reported transition temperature.