Chaperone‐like activity and surface hydrophobicity of 70S ribosome

FEBS Letters

Singh, Ranvir¹  Rao, Ch.Mohan¹ 

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

关键词: Ribosome;    Protein;    Folding;    Aggregation;    Chaperone;    Hydrophobicity;    Insulin;    Crystallin;    Lactalbumin;    ANS;    8-anilino-1-naphthalene sulfonate;    DTT;    dithiothreitol;    BCA;    bovine carbonic anhydrase;    TMA-10;    Tris–HCl buffer (pH 7.5) 30 mM ammonium chloride;    5 mM mercaptoethanol with 10 mM magnesium acetate;   

DOI  :  10.1016/S0014-5793(02)03243-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Ribosomes have been shown to mediate refolding of proteins in vitro. In order to understand the mechanism of action, we have explored the 70S ribosome surface for hydrophobicity, one of the important aspects in chaperone–target protein interaction. We find that the 70S ribosome displays significant hydrophobicity on its surface when probed with the hydrophobic fluorophore 8-anilino-1-naphthalene sulfonate. To understand the functional significance of this hydrophobicity we investigated the ability of the ribosome to prevent aggregation of insulin B chain and α-lactalbumin induced by reducing the interchain and intrachain disulfide bond respectively with dithiothreitol (DTT) and photo aggregation of γ-crystallin at 37°C. The 70S ribosome offers complete protection towards light-induced aggregation of γ-crystallin (at 1:2 (w/w) ratio of crystallin:ribosome) and DTT-induced aggregation of α-lactalbumin (at 1:3) and there is appreciable protection (at 1:3) against the aggregation of insulin B chain. We also investigated the role of 70S ribosome in refolding of bovine carbonic anhydrase. Ribosomes improved the folding yield in a concentration-dependent manner. These results clearly demonstrate a general chaperone-like activity of 70S ribosome and implicate its surface hydrophobicity.

【 授权许可】

Unknown