Interaction of human recombinant αA‐ and αB‐crystallins with early and late unfolding intermediates of citrate synthase on its thermal denaturation

FEBS Letters

Rajaraman, K¹  Raman, B¹  Ramakrishna, T¹  Rao, Ch.Mohan¹ 

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

关键词: α-Crystallin;    Molecular chaperone;    Citrate synthase;    Unfolding intermediate;    Interaction;   

DOI  :  10.1016/S0014-5793(01)02451-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have investigated the role of recombinant human αA- and αB-crystallins in the heat-induced inactivation and aggregation of citrate synthase. Homo-multimers of both αA- and αB-crystallins confer protection against heat-induced inactivation in a concentration-dependent manner and also prevent aggregation. Interaction of crystallins with early unfolding intermediates of citrate synthase reduces their partitioning into aggregation-prone intermediates. This appears to result in enhanced population of early unfolding intermediates that can be reactivated by its substrate, oxaloacetate. Both these homo-multimers do not form a stable complex with the early unfolding intermediates. However, they can form a soluble, stable complex with aggregation-prone late unfolding intermediates. This soluble complex formation prevents aggregation. Thus, it appears that the chaperone activity of α-crystallin involves both transient and stable interactions depending on the nature of intermediates on the unfolding pathway; one leads to reactivation of the enzyme activity while the other prevents aggregation.

【 授权许可】

Unknown