Analysis of crystallin-crystallin interactions by surface plasmon resonance.
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 BlAcore system. Lens proteins are composed mainly of three types crystallins, alpha-, beta-, and gamma-crystallin. The present study indicated that alpha-crystallin shows marked self-interaction. Furthermore, this interaction was shown to be due to alphaA-crystallin, which is a subunit of alpha-crystallin. It was also clarified that this mutual interaction of aA-crystallin decreases abruptly after the age of 20 years. On the other hand, it was assumed that alphaB-crystallin, the other subunit of alpha-crystallin, may play an important role in interactions with beta- and gamma-crystallin, while a-crystallin shows chaperone-like activity. Based on the present results, alphaA- and betaB-crystallin may play different roles when alpha-crystallin displays chaperone-like activity, and also that the decreased chaperone-like activity of a-crystallin may finally result in cataract formation following aggregation and insolubilization of lens proteins.
Kamei
Akira
A
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Meijo University, Nagoya-shi, Aichi, Japan. kamei@meijo-u.ac.jp
Matsuura
Nobuyuki
N
D000595:Amino Acid Sequence; D001665:Binding Sites; D002852:Chromatography, Ion Exchange; D003459:Crystallins / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007536:Isomerism; D007700:Kinetics; D007908:Lens, Crystalline / Q000737:chemistry; D008969:Molecular Sequence Data; D020349:Surface Plasmon Resonance; D014357:Trypsin
D003459:Crystallins; D014357:Trypsin