Inhibition of Heat-Induced Aggregation of beta- and gamma-Crystallin by alpha-Crystallin Evaluated by Gel Permeation HPLC

L. Saso, E. Grippa, M. T. Gatto, M. G. Leone, and B. Silvestrini^*

Department of Pharmacology of Natural Substances and General Physiology, University of Rome “La Sapienza”, Piazzale Aldo Moro 5, 00185 Rome, Italy; fax: +39649912480; E-mail: silvestrini@uniroma1.it

^* To whom correspondence should be addressed.

Received April 26, 1999; Revision received June 28, 1999

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The capability of alpha-crystallin (alpha-C), a known molecular chaperon, of protecting beta-C and gamma-C against heat-induced aggregation was studied by gel permeation high performance liquid chromatography. The activity was calculated using a formula based on the changes in the areas under the chromatographic peaks of these proteins, which appeared well separated. When heat-induced aggregation was studied in the range 22-90°C, beta-C appeared more stable than gamma-C. The activity of alpha-C in stabilizing gamma-C but not beta-C was already relevant at 60°C, but the maximum activity was higher (about 35%) for beta-C than for gamma-C. This method could be useful for studying the effect of drugs with potential anti-cataract activity on heat-induced aggregation of individual lens proteins.

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KEY WORDS: crystallins, denaturation, gel permeation high performance liquid chromatography,anti-cataract drugs

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