Alpha-crystallin does not require temperature activation for its chaperone-like activity.
alpha-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 degrees C of alpha-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 alpha-crystallin was studied at a number of temperatures above and below 30 degrees 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 gamma-crystallin. Contrary to the above notion, the results indicate that alpha-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.
Bhattacharyya
J
J
Department of Chemistry, Bose Institute, Calcutta, India.
Das
K P
KP
D003459:Crystallins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D016650:Fluorescein-5-isothiocyanate; D007328:Insulin / Q000737:chemistry* / Q000378:metabolism; D018832:Molecular Chaperones / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence; D013696:Temperature; D014466:Ultraviolet Rays
D003459:Crystallins; D007328:Insulin; D018832:Molecular Chaperones; D016650:Fluorescein-5-isothiocyanate