Enhanced stability of αB-crystallin in the presence of small heat shock protein Hsp27

• Published in: Biochemical and biophysical research communications 2003-03, Vol.302 (4), p.710-714
• Main Authors: Fu, Ling, Liang, Jack J.-N
• Format: Article
• Language: English
• Subjects: alpha-Crystallin B Chain - chemistry; alpha-Crystallin B Chain - genetics; alpha-Crystallin B Chain - metabolism; Animals; Circular Dichroism; Heat-Shock Proteins - chemistry; Heat-Shock Proteins - genetics; Heat-Shock Proteins - metabolism; Hsp27; Humans; Lens αB-crystallin; Molecular Weight; Protein Conformation; Recombinant Proteins - chemistry; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Small heat shock protein; Temperature; Thermal stability
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/S0006-291X(03)00257-2

Lens α-crystallin, αA- and αB-crystallin, and Hsp27 are members of the small heat shock protein family. Both αA- and αB-crystallin are expressed in the lens and serve as structural proteins and as chaperones, but αB-crystallin is also expressed in nonlenticular organs where Hsp27, rather than αA-crystallin, is expressed along with αB-crystallin. It is not known what additional function Hsp27 has besides as a heat shock protein, but it may serve, as αA-crystallin does in the lens, to stabilize αB-crystallin. In this study, we investigate aspects on conformation and thermal stability for the mixture of Hsp27 and αB-crystallin. Size exclusion chromatography, circular dichroism (CD), and light scattering measurements indicated that Hsp27 prevented αB-crystallin from heat-induced structural changes and high molecular weight (HMW) aggregation. The results indicate that Hsp27 indeed promotes stability of αB-crystallin.