Redox‐regulated chaperone function and conformational changes of Escherichia coli Hsp33

FEBS Letters

Mohan Rao, Ch¹  Raman, B¹  Ramakrishna, T¹  Siva Kumar, L.V¹ 

[1] Centre for Cellular and Molecular Biology, Hyderabad 500 007, India

关键词: Molecular chaperone;    Heat shock protein 33;    Oxidative activation;    Conformation;    Hydrophobic surface;   

DOI  :  10.1016/S0014-5793(01)02074-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have studied the chaperone activity and conformation of Escherichia coli heat shock protein (Hsp)33, whose activity is known to be switched on by oxidative conditions. While oxidized Hsp33 completely prevents the heat-induced aggregation of ζ-crystallin at 42°C at a ratio of 1:1 (w/w), the reduced form exhibits only a marginal effect on the aggregation. Far UV–circular dichroism (CD) spectra show that reduced Hsp33 contains a significant α-helical component. Oxidation results in significant changes in the far UV–CD spectrum. Near UV–CD spectra show changes in tertiary structural packing upon oxidation. Polarity-sensitive fluorescent probes report enhanced hydrophobic surfaces in the oxidized Hsp33. Our studies show that the oxidative activation of the chaperone function of Hsp33 involves observable conformational changes accompanying increased exposure of hydrophobic pockets.

【 授权许可】

Unknown