Analysis of crystallin-crystallin interactions by surface plasmon resonance

Abstract

The mechanism of aggregation and insolubilization of lens proteins was examined based on the kinetics of crystallin-crystallin interaction determined by the surface plasmon resonance method on a BIAcore system. Lens proteins are composed mainly of three types crystalline, α-, β-, and γ-crystallin. The present study indicated that α-crystallin shows marked self-interaction. Furthermore, this interaction was shown to be due to αA-crystallin, which is a subunit of α-crystallin. It was also clarified that this mutual interaction of αA-crystallin decreases abruptly after the age of 20 years. On the other hand, it was assumed that αB-crystallin, the other subunit of α-crystallin, may play an important role in interactions with α- and γ-crystallin, while α-crystallin shows chaperone-like activity. Based on the present results, αA- and βB-crystallin may play different roles when α-crystallin displays chaperone-like activity, and also that the decreased chapcrone-like activity of α-crystallin may finally result in cataract formation following aggregation and insolubilization of lens proteins.