αA-crystallin-derived minichaperone stabilizes αAG98R-crystallin by affecting its zeta potential.

The G98R mutant of αA-crystallin is associated with the development of presenile cataracts. In vitro， the recombinant mutant protein exhibits altered structural and functional characteristics， along with the propensity to aggregate by itself and precipitate. Previously， we have reported that the N-terminal aspartate substituted form of the antiaggregation peptide， DFVIFLDVKHFSPEDLTVK (αA-minichaperone or mini-αA) prevented aggregation of αAG98R. However， the mechanism of stabilization of αAG98R from aggregation is not fully understood. The purpose of this study was to determine whether the surface charge (zeta (ζ) potential) of αAG98R in the presence of the peptide chaperone contributed to the stabilization of mutant protein， and to identify the sites of interaction between αAG98R and the peptide chaperone.