| Summary: | 碩士 === 國立成功大學 === 化學系碩博士班 === 93 === α-Crystallin is a members of the family of small-heat-shock proteins.To investigate the structure and chaperone-like activity relationship, wereplaced Asp69 in rat lens αA-crystallin with a positive charged Argresidue and with a hydrophobic Trp residue respectively by site-directedmutagenesis. In comparison with the recombinant αA-crystallin, themutant proteins D69R and D69W displayed similar secondary structureand tertiary structure. ANS fluorescence showed a little higherhydrophobicity for both mutant proteins. Mutant D69R showed similarchaperone-like activity as the recombinant αA-crystallin, whereas mutantD69W showed dramatic changes in the chaperone-like activity. Thermalstability of both D69R and D69W were lower than that of native andrecombinant αA-crystallin. The chaperone-like activity of recombinantαA-crystallin and D69R were enhanced with the increase of temperature,but D69W still showed little chaperone-like activity. Thus, a hydrophilicresidue must be preserved at this position to maintain its structural andfunctional integrity of αA-crystallin.
|
|---|
